AltME groups: search

(but can never solve the switch problem completely, because any value 
used as default could appear in the block  - you have to use find)

i'd actually implement switch using parse. i find it very useful 
to be able to specify multiple values for the same block.

switch1: func [
    "Selects a choice and evaluates what follows it."
    [throw]
    value "Value to search for."
    cases [block!] "Block of cases to search."
    /default case [block!] "Default case if no others are found."
    /local blk
][
	value: find cases value
	if value [value: find next value block!]
    either value [do first value] [if default [do case]]
]

parse find block value [to block! ..etc..]

I'm enamoured with the multiple action block version, so I'll see 
if I can make a nice FIND-based version of that.

Ok, here it is:
; FIND-based, multi-action
switch3: func [

    "Selects a choice and evaluates the first block that follows it. 
    This occurs for every matching value and following block found."

    [throw] ; <-- allows RETURN to be used by the user to jump out of 
    an enclosing function (not just this one)
    value "Value to search for."
    cases [block!] "Block of cases to search."
    /default case [block!] "Default case if no others are found."

    /local result done? ; <-- flag so we know whether an action block 
    was done. (Can't just check 'result, could be unset!)
][
	while [cases: find cases value][

  either cases: find next cases block! [set/any 'result do first cases 
  done?: yes][break]
	]
	either done? [
		get/any 'result
	][
		if default [do case]
	]
]


my-switch: :switch3   ; <--- set to the function we want to test


;test
repeat n 10 [
	print [
		n

  my-switch/default n [2 4 6 ['even] 1 3 5 ['odd]] [mold "--default--"]
	]
]
my-switch 1 []
my-switch/default 1 [] [probe "--default, ok--"]
my-switch 1 [1 [probe "ok"]]
my-switch 2 [1 [probe "bad"]]
my-switch 1 [1 2 [probe "ok"]]
my-switch 2 [1 2 [probe "ok"]]
my-switch 3 [1 2 [probe "bad"]]

; multiple action blocks
my-switch 1 [1 2 [probe "ok"] 1 3 4 [probe "ok#2"]] ; <-- 
my-switch 2 [1 2 [probe "ok"] 1 3 4 [probe "bad"]]
my-switch 3 [1 2 [probe "bad"] 1 3 4 [probe "ok"]]
my-switch 4 [1 2 [probe "bad"] 1 3 4 [probe "ok"]]
my-switch 5 [1 2 [probe "bad"] 1 3 4 [probe "bad"]]


my-switch/default 5 [1 2 [probe "bad"] 1 3 4 [probe "bad"]] [probe 
"--default, ok--"]

anyone built a function to find duplicate elements in a block and 
return them in a separate block?

; Something like this?


    split-unique: func [block [any-block!] /local uniq dupe dest] [
        uniq: copy []
        dupe: copy []
        foreach item block [
            dest: either find/only uniq item [dupe] [uniq]
            append/only dest item
        ]
        reduce [uniq dupe]
    ]

you got me into a spin, I rarely do this kind of fun , here is my 
best and shortest solution:

(its also 3 times faster than Geomol's, using his block data ;-)

duplicates: func [serie /local word][

 remove-each word copy serie [same? find serie word find/last serie 
 word] 
]

>> duplicates [a b b c b a]
== [a b b b a]

you can add the 'unique call to clean up the block if you like 
>> unique duplicates  [1 1 2 2 3 4 5 5 6 7 8]
== [1 2 5]

(before using SAFE-EVAL you should test the first element of the 
STM-BLOCK to find out whether it is one of the functions you are 
willing to evaluate)

Anyway... I'm thinking, that maybe it would be good to find solution 
where I will not need nested block at all.

yeah... I think the conclusion is ... don't worry about the number 
of bytes (and thus mem) when using plain integers with my index block, 
as it's much smaller than the dictionary anyways.. and unless Im 
shown otherwise, the crawling of it (find/ foreach, append) should 
be about as fast as any other method, right?

This is the client; put it in the folder containing the files you 
want to send.

rebol []
ip: request-text/title/default "IP Address: " "localhost"
port-num: request-text/title/default "Port Number: " "2006"
url: to-url rejoin ["tcp://" ip ":" port-num]
system/options/binary-base: 64  ; best binary encoding


print ["This program SENDS all files in its folder to receive-files-tcp." 
newline]
print "NOTE: receive-files-tcp must be running on the remote"
print ["computer before starting this program." newline]

files: read %. ; Note that 'files is a block of file names.
save %file-names files
server: open url

insert server compress as-binary read/binary %file-names ;send file 
names
file-block: []
foreach file files [
    if not find file "/" [insert file-block file] ;remove folders
]
files: file-block
foreach file files [
    insert server compress as-binary read/binary file
    print ["Successfully sent file: " file]
]
close server

ask [newline "The files transfer is complete. Press <Enter> to close."]

Given a block with one element:
>> blk: [1]
== [1]
I move the blk pointer forward one position:
>> blk: next blk
== []
I then append one element:
>> append blk 1
== [1 1]

and the head of blk is shown, which is the behaviour of append. The 
address of blk is the same:
>> blk
== [1]
I now clear the whole block:
>> clear head blk
== []
and append yet another element to the now empty block:
>> append blk 1
== [1]
But blk now points to the tail of the block!
>> blk
== []

Shouldn't I see the element at the position of blk? I mean, blk should 
now point to the head of the block, right? I couldn't find this in 
RAMBO.

Gregg, well in the back of my mind since I started programming with 
BASIC, C and Assembler (which, without wanting to start an Altme-war, 
I refer to as 'procedural' as opposed to OO), I was just wondering 
if there was another "object-oriented" way. You know, like "find" 
but with special parameters that tell it to do what my "foreach" 
actually does. I don't know, it just seemed kind of "Dorky." : )

I'm writing an app that will produce php code to help me administer 
mysql db's. I'm at the point where it can read the table and field 
data and create objects with that info. Now I'm at the part where 
it goes back and pulls that data out. So, I've assigned each table 
an index # then in the "columns" object, it refers back to that index. 
Since I have a block of those column objects I was just looking for 
a spiffy way of finding which ones, for example, of finding all of 
the objects that are part of table index #3.

I've always used the "foreach " method but you know, I'm always looking 
for a way to improve my code. Thanks Gregg for your input.

Hi Rebol community, I was wondering about how you deal with error 
handling in Rebol in those situations where you have a number of 
network operations which are likely to fail part of the time. Of 
course, you already raised the timeout for network protocols (system/schemes/default/timeout: 
0:10). Now say your script contains a number of network operations 
(read url, for example) wrapped in user functions. This is a very 
common situation.

For example:

fetch-actual-ip: does [

        page: read-url-with-basic-auth http://192.168.1.1/Status.htm(http-basic-auth-key 
        router_username router_password)
	parse page [thru <td class="stdbold" nowrap> copy ip to </td>]
	return to-tuple ip
]


Now this is fine, but if your read operation fails, the script will 
abort. You would like the function to try again a couple of times.


The first thing you would be tempted to do is to redefine the function 
to repeat the function in case of error or unexpected result. A recursive 
function like the next one may provide some solace: 

fetch-actual-ip: does [

        page: read-url-with-basic-auth http://192.168.1.1/Status.htm(http-basic-auth-key 
        router_username router_password)
        either none? tmp: find/tail page "ip address"
                [
                print "Retrying..."
                retries: retries + 1

                if retries > 10 [print "Retried 10 times. Exiting" quit]
                fetch-actual-ip
               ] [

                parse tmp [thru <td class="stdbold" nowrap> copy ip to </td>]
                retries: 0
                return to-tuple ip
                ]
]


You might have a number of user functions and each can fail, so transforming 
every user function into a recursive one with its own error handling 
block can be tedious. 


Wouldn't it be better to abstract the process with a meta-function 
that accepts as input the user function itself? The error handling 
logic would then be exclusively handled by that meta-function, which 
will save you from redundancy if you have multiple user functions. 

Let's do it:


retry: func [external_function [function!] retries [integer!] /local 
.retry [function!] tries [integer!] value] [
	tries: 0
	.retry: func [.external_function [function!]] [
		either not error? try [value: .external_function]
			[
			if not none? value [return value]
			]
			[
			print "Retrying..."
			tries: tries + 1

   if tries > retries [print rejoin ["Tried function " tries " times. 
   Exiting"] return]
			.retry :.external_function
			]
	]
	.retry :external_function
]

Now you call the short version of fetch-actual-ip like this:

retry :fetch-actual-ip 5

(try the user function 'fetch-actual-ip up to 5 times)

Anyone wants to comment or improve on this?

Another opinion piece;
While developing I've taken to starting each script with


;; if a symbol exists and is true, when will evaluate the block of 
code
;; when/not will evaluate the code if the symbol is not set
when: func ['condition [word!] code [block!] /not] [
    either not [
        unless value? condition code
    ][
        if all [value? condition  get condition] code
    ]
]

This allows for

; See if testing requested as script argument or it could be set 
by a caller
when/not testing [

    if all [system/script/args  find system/script/args "/test"] [
        testing: on
    ]
]
; If requested, try loading the test facility or stub it.
when testing [
    absent test [
        if error? try [do %../Test/test.r] [
            test: func ["test stub" drop [block!]] []
        ]
    ]
]


I had been using  given  and  absent (for when/not).  Anyone got 
a better way of handling conditional load sequences and command line 
argument passing that supports development cycles while not having 
to change the code for testing, autodocing  and production rollout?

I am trying to pull some information out of a moderately formatted 
wiki and am tripping over something simple.


I have grabbed what equates to a record in a table so far that looks 
as follows.

||Key 123||Description text||Status||02/23/08||Y||

I have parse giving me this as a block of values.


Since this wiki is only loosely formatted the first field varies 
one line to the next, sometimes might just be Key, or *Key ###.  
What I am working too hard at is how to test a line is a pure Key 
### value.  I went looking using find for "Key "(with the space) 
 values but that still picks up "*Key ###" values.  I have multiple 
key types but generally it follows the pattern of trying to avoid 
the leading * lines and any line that isn't a known Key with some 
number following it.


My old procedural habits would like a simple substring so I can test 
from the beginning for x number of characters.


I have tried copy/part but am not getting the range syntax correct.


I am also thinking I should just further split the field to the key+number 
so I can test that both parts exist and have appropriate values. 

Suggestions or nudges towards enlightenment?

; I liked this feature of ICON/UNICON where a func can have an initially 
block so I have this in REBOL
initial: func [wd [word!] /list /local functions]
  [
    functions: []
    if list [return functions]
    f: find functions wd
    either (found? f) 
      [return false] 
      [append functions wd return true]
  ]    


initially: func ['wd [lit-word!] blk [block!]][
    if (initial wd) [do blk]
]
; and to test initially
test: func [str [string!] /local prefix [string!]][
    prefix: ""
    initially 'test [prefix: "tested "]
    print [prefix str]
]
; which runs as, say
test "this"
; first time giving "tested this" and thereafter "this"
; thoughts on whether useful enough to go into the org library ?

It relies on the FIND finding blocks based on whether they are the 
same, not equal. That means that the reference to the code block 
that is passed to INITIALLY can itself be used as a tag.

To check for the logic! value FALSE, you have to reduce the block:


>> if find reduce [false true] false [print "The logic! value false 
is in the series"]
The logic! value false is in the series

>> if find reduce ['false true] false [print "The logic! value false 
is in the series"]
== none

Diss'ing IDE's might alienate some Smalltalk folk.  I cannot imagine 
maintaining an application suite such as I deal with everyday without 
an IDE.  I just wish it was not eclipse ...  Of course only wimps 
used a Disk Operating System and real men code in machine codes only 
... and real pro's dictated their SNOBOL punch cards to lovely assistants 
...  and ANT scripts are for sissies.  Some must have ridiculed Tcl, 
Expect and TK in their day ... but if my IDE can facilitate my efforts 
to systematically (key word there) shrirnk company''s codebase as 
it becomes more reliable with better test coverage then maybe a refactoring 
browser would be a good tool after all.  Even better if it is an 
integrated part of the IDE, as in Dolphin Smalltalk or Squeak Smalltalk 
or Smalltalk/X or Cincom Visual Smalltalk.  Not that I couldn't survive 
on grep and diff's.  But once the codebase is too large for any one 
person to author or maintain on their lonesome, a tool that remebers 
what you did last and where can be a god-send.  If you want to know 
hell without an IDE join an actuarial department working in APL. 
 There you don't even know if they have talent: you just hope most 
of it works as each quarter rolls around and try to survive year-end. 
 But you know they're smart, cuz after all, they're actuaries - and 
look at all that APL code in all those files ... of course a few 
of them look back wistfully at their student days in C with Borland's 
decent IDE.  REBOL [
    File: %vid-usage.r
    Date: 09-Jan-2004   
    Title: "VID Usage"
    Purpose: "VID Usage Tutorial with Runnable Examples"
    Version: 1.2.1
    Author: "Cybarite"
    Edits: RobertS
    Source: {
        Based on %easy-vid.r by Carl Sassenrath.

        Clips from various sites including email that are attributed in the 
        section
        }
    library: [
        level: 'intermediate
        platform: 'all
        type: [tutorial]
        domain: [gui]
        tested-under: [view 1.2.8.3.1 on W2K]
        support: none
        license: none
        see-also: none
    ]
]
 
flash "Fetching image..."
read-thru/to http://www.rebol.com/view/demos/palms.jpg%palms.jpg

read-thru/to http://www.rebol.com/graphics/reb-logo.gif%rebo-logo.gif
read-thru/to http://www.rebol.com/view/bay.jpg%bay.jpg
pic: %palms.jpg
unview

customer: make object! [  ; this sets a default customer object in 
case the user does not push the samples in order
        name: "Rosetta Stone"
        date-of-birth: 14-March-1959        
]

stylize/master [text-note: txt maroon bold]         ; this sets a 
default for users who run the samples out of order
; polished is an image that is embedded in this script file
; so that no outside files need to be loaded.
; This technique is used in many of the REBOL samples

polished: load #{      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}
content: {VID Usage - REBOL Visual Interfaces


===Updates

--01-Apr-2008


* Fixed oddity with last item on stylesheets which was locking up 
some versions of VIEW

---09-Jan-2004

* Fixed slider initialize. 

* Focus section was not parsed out. --- fixed

* Fixed some text errors for the parsing of ===


---07-Jan-2004

* Revived vid-usage.r 

* added more examples from the script library

* manage source as vid-usage.leo an outliner file

---12-August-2001

Added supply examples. See:

!List/Supply

!List With Supplied Data

!Supply List With Scroll

---13-August-2001

!Add Subpanel example ported by Anton

===Caveats

---Work In Progress


This is a work in progress. Whether the progress will continue depends 
on the feedback.

---All Rights Reserved


The work is based on the documentation of REBOL View provided by 
REBOL Technology and its mailing list.

All rights to this documentation remain the property of REBOL Technology.

---Plagiarized Examples


Things are shamelessly plagiarized.  There are many experts on the 
mailing list whose work is included here; most notably the examples 
from the REBOL documentation.

---Approach


The approach that this document uses is to use REBOL/View/VID to 
demonstrate its abilities and give a visual tutorial. To enable this 
some changes have been made to the core %easyvid.r program from Carl 
Sassenrath. A scoll bar was added to the right pane because it was 
just too difficult to constrain the examples to the screen real estate 
that was available.

---Order Order


The order of the items needs some work. The easyvid presentation 
approach today does not allow for the drilling down and expansion 
of an outline tree which is needed for a large amount of documentation.


The preferred approach is to put a multi-level tree for navigation 
purposes and then allow navigation up and down the tree. 


===To Do

* make this a true outline tree

* re-organize it better


* update as requested and as possible by suggestions on AltME's REBOL 
world under group EasyVID

* correct numerous flaws


* better scrolling implementation using the updates that have been 
used in other examples such as Didier's %delete-email.r


* allow clipping to clipboard like AltME does on a row for the source 
examples




===Introduction to VID

With REBOL/View it's easy and quick to create your own user
interfaces. The purpose of this tutorial is to teach you the
basic concepts or REBOL/View interfaces in about 20 minutes.

VID is REBOL's Visual Interface Dialect.  A dialect is an
extension of the REBOL language that makes it easier to express
or describe information, actions, or interfaces.  VID is a
dialect that provides a powerful method of describing user
interfaces.

VID is simple to learn and provides a smooth learning curve from
basic user interfaces to sophisticated distributed computing
applications.


---Creating VID Interfaces

VID interfaces are written in plain text. You can use any text
editor to create and edit your VID script. Save your script
as a text file, and run it with REBOL/View.

!Note: Using a word processor like Word or Wordpad is not
recommended because files are not normally saved as text.
If you use a word processor, be sure to save the output
file as text, not as a document (.doc) file.


Recommendation: Look at TextPad from http://www.textpad.com




===Minimal VID Example

Here is a minimal VID example.  It creates a window that
displays a short text message.  Only one line of code
is required:

    view layout [text "Hello REBOL World!"]

You can type this line at the REBOL console prompt, or save
it in a text file and run it with REBOL.  If you save it
as a file, the script will also need a REBOL header. The
header tells REBOL that the file contains a script. Here
is an example of the script file with a header:

    REBOL [Title: "Example VID Script"]

    view layout [text "VID Example!"]

You can also add buttons and other gadgets to the script. The
example below displays a text, list of files, and a button:

    view layout [
        h2 "File List:"
        text-list data read %.
        button "Great!"
    ]

!Click on the examples above to see how they will appear on your
screen.  Click on their close box to remove them.  All of the
examples that follow can be viewed this way.


===Window Management


The code that displays the examples also shows how to manage the 
number of windows that are open.


Look at the show-example block in the code near the end of this script.


The location of the example window is also managed here by keeping 
track of the co-ordinates for the sample. After the sample window 
is moved, the next use will open at the same location.



===Pre-loaded Images


For this script, the image which represented a Portable Network Graphic
definition of an image is held in the script and loaded.


For a small number of graphics, this can achieve some packaging and
performance benefits.


The image "polished" is used through the script to achieve the polished 
steel
look that is one the outer frame.

    backtile polished orange
    button 200x50 "Polished Steel Look" polished 


===Two Basic Functions

Two functions are used to create graphical user interfaces
in REBOL: VIEW and LAYOUT.

The LAYOUT function creates a set of graphical objects.  These
objects are called faces.  You describe faces with words and

values that are put into a block and passed to the LAYOUT function.

The VIEW function displays faces that were previously created by
LAYOUT. The example below shows how the result of
the LAYOUT function is passed to the VIEW function, and the
interface is displayed.

    view layout [
        text "Layout passes its result to View for display."
        button "Ok"
    ]

Click on the above example to view it.

!Note: the block provided to a layout is not normal REBOL code,
it is a dialect of REBOL.  Using a dialect makes it much easier
to express user interfaces.



===Styles

Styles describe faces.  The examples above use the text and
button styles to specify a text line and a button. REBOL has
40 predefined face styles. You can also create your own custom
styles.  Here are a few example styles:

    view layout [
        h1 "Style Examples"
        box brick 240x2
        vtext bold "There are 40 styles built into REBOL."
        button "Great"
        toggle "Press" "Down"
        rotary "Click" "Several" "Times"
        choice "Choose" "Multiple" "Items"
        text-list 120x80 "this is" "a list" "of text"
        across
        check
        radio radio
        led
        arrow
        below
        field "Text Entry"
    ]


The words like backdrop, banner, box, text, and button are styles.

===Facets

Facets let you modify a style.  For instance, you can change the
color, size, text, font, image, edge, background, special
effects, and many other facets of a style.

Facets follow the style name.  Here is an example that shows
how you modify the text style to be bold and navy blue:

    view layout [txt bold navy "Facets are easy to use."]

The words bold and navy are not styles.  They are facets that
modify a style. Facets can appear in any order so you don't
have to remember which goes first.  For example, the line
above could be written as:

    view layout [txt "Facets are easy to use." navy bold]

Many facets that can be specified.  Here is an example that
creates bold red text centered in a black box.

    view layout [txt 300 bold red black center "Red Text"]

You can create facets that produce special effects, such
as a gradient colored backdrop behind the text:

    view layout [
        vtext bold "Wild Thing" effect [gradient 200.0.0 0.0.200]
    ]

===Custom Styles

Custom styles are shortcuts that save time.  When you define a
custom style, the facets you need go into the new style.  This
reduces what you need to specify each time you use the style,
and it allows you to modify the look of your interface by
changing the style definitions.

For example, here is a layout that defines a style for red
buttons.  The style word defines the new style, followed by
the old style name and its facets.

    view layout [
        style red-btn button red
        text "Testing red button style:"
        red-btn "Test"
        red-btn "Red"
    ]

So, if you wanted to create a text style for big, bold,
underlined, yellow, typewriter text:

    view layout [
        style yell tt 220 bold underline yellow font-size 16
        yell "Hello"
        yell "This is big old text."
        yell "Goodbye"
    ]


===Master Stylesheet 

REBOL holds its styles in a master stylesheet. When you are
sure that you want to share them without having to add the
style sheet line then do it as follows:

First add the style to the master sheet:

    button 200x50 "Define text-note as maroon bold text" [stylize/master 
    [
        text-note: txt maroon bold      
    ]]

    button 200x50 "Define text-note as white italic text" [stylize/master 
    [
        text-note: txt white italic     
    ]]

Then invoke it:

    view layout [
        across
        size 200x200

        return text-note "This shows a master stylesheet style in use." 

        return text-note "This shows another usage of the same style."

        return text-note "If you want to see the other style displayed, click 
        the Add Style section again and then use the other button"
    ]
    
    
===Note About Examples

!From this point forward, all examples will assume that
the view and layout functions are provided.  Only the layout
block contents will be shown.  To use these examples in your
scripts, you will need to put them in a layout block, as was
shown earlier.

For example, code that is written as:

    view layout [button red "Test it"]

will now appear as:

    button red "Test it"


===Face Sizes

The size of a face depends on its style.  Most styles, such as
buttons, toggles, boxes, checks, text-lists, and fields, have a
convenient default size.  Here are some examples.

    button "Button"
    toggle "Toggle"
    box blue
    field
    text-list

If no size is given, text will automatically compute its size,
and images will use whatever their source size is:

    text "Short text line"
    text "This is a much longer line of text than that above."
    image %palms.jpg

You can change the size of any face by providing a size facet.
The size can be an integer or a pair.  An integer specifies
the width of the face.  A pair specifies both width and height.
Images will be stretched to fit the size.

    button 200 "Big Button"
    button 200x100 "Huge Button"
    image %palms.jpg 50x50
    image %palms.jpg 150x50

===Color Facets

Most styles have a default color.  For example the body of
buttons will default to a teal color.  To modify the color of
a face, provide a color facet:

    button blue "Blue Button"
    h2 red "Red Heading"
    image %palms.jpg orange

Colors can also be specifed as tuples. Each tuple contains three
numbers: the red, green, and blue components of the color. Each
component can range from 0 to 255. For example:

    button 200.0.200 "Red + Blue = Magenta" 200
    image %palms.jpg 0.200.200 "Green + Blue"

Some face styles also allow more than one color.  The effect of
the color depends on the style.  For text styles the first color
will be used for the text and the second color for the background
of the text:

    txt "Yellow on red background" yellow red
    banner "White on Navy Blue" white navy

For other styles, the body of the face is the first color, and
the second color will be used as its alternate.

    button "Multicolor" olive red
    toggle "Multicolor" blue orange
===Layout Commands


To drop user interface elements on the canvas according to VIDs 
directional layout controls 

---Across

You are placing elements in a row orientation
    
    across 
    return button "A" button "B" button "C"
    return button "D" button "E" button "F"
    

---Below

You are placing elements in a column orientation

    below 
    return button "A" button "B" button "C"
    return button "D" button "E" button "F"

---Mix

You can mix the directional controls 

    across 
    return button "A" button "B" 
    below button "C" 
    across button "D" button "E" button "F"


---Padding


The pad keyword creates extra padding between styles. It uses a pair 
or integer value. When it is an integer, spacing is created either 
horizontally (across) or vertically (below). When it is a pair, the 
spacing will be created both horizontal and vertically. The following 
example illustrates both uses. First, the buttons "one" and "two" 
are padded with an integer representing 40 pixels in one direction. 
Then the buttons "three" and "four" are padded with a pair representing 
40x40 pixels. 

    across 
    button "one" pad 40 button "two" return 
    button "three" pad 40x40 button "four" 


Padding can be negative.
    
        backtile polished orange
        pad 200x200 button "A"
        pad -100x-100 button "B"
        
---Guide

A guide is a virtual alignment control

      title "Buttons Without A Guide" 
    button "one"   button "two"  return 
    button "three" button "four" return 
    button" five" button "six" 

With an implicit guide location

    title "Buttons With An Implicit Guide Location" 
    guide 
    button "one"   button "two"  return 
    button "three" button "four" return 
    button" five" button "six" 

With an explicit guide location

    across title "Buttons With An Explicit Guide Location"
    guide 55x100 
    button "one"   button "two"  return 
    button "three" button "four" return 
    button" five" button "six" 
    
===Tabstops

Tabs can be used for alignment.

---Across

    tabs 200 ; sets tabs every 200 pixels   
    across button 20 "A" tab button 20 "B" tab button 20 "C" 
    tabs 100 ; sets tabs every 100 pixels   
    return button 20 "D" tab button 20 "E" tab button 20 "F"
    
---Below

    tabs 200 ; sets tabs every 200 pixels   
    below button 20 "A" tab button 20 "B" tab button 20 "C" 
    tabs 100 ; sets tabs every 100 pixels   
    return button 20 "D" tab button 20 "E" tab button 20 "F"

---Explicit Settings

Tabstops can be set at explicit values 

    tabs [100 124  166 212 300]

    across tab button 20 "A" tab button 20 "B" tab button 20 "C" tab 
    button 20 "D"
    
===Color Facets

Most styles have a default color.  For example the body of
buttons will default to a teal color.  To modify the color of
a face, provide a color facet:

    button 200 blue "Blue Button"
    h2 red "Red Heading"
    image polished orange

Colors can also be specifed as tuples. Each tuple contains three
numbers: the red, green, and blue components of the color. Each
component can range from 0 to 255. For example:

    button 200.0.200 "Red + Blue = Magenta" 200
    image polished 0.200.200 "Green + Blue"


Some face styles also allow more than one color.  The effect of the 
color depends on the style.  For text styles the first color will 
be used for the text and the second color for the background of the 
text:

    txt "Yellow on red background" yellow red
    title "White on Navy Blue" white navy


For other styles, the body of the face is the first color, and the 
second color will be used as its alternate.

    button 200 "Multicolor" olive red
    toggle 200 "Multicolor" blue orange


From the mailing list, there was a problem reported in changing button 
color:

    view layout [
        b: button "New color" [
            b/color: random 255.255.255 
            show b
        ]
    ]
    

And the answer was that the gradient of the color was preventing 
this change from working:


    style color-changing-button button 0.0.0        ; new style overwrites 
    gradient effect
    b: color-changing-button "New color" [
        b/color: random 255.255.255 
        show b
    ]

===Text Facets


Most faces will accept text to be displayed.  Even graphical faces 
can display text.  For example, the box and image faces will display 
text if it is provided:

    box blue "Box Face"
    image polished "Image Face"


Most button faces will accept more than one text string. The strings 
will be shown as alternates as the face is selected.

    button 200 "Up" "Down"
    toggle 200 "Off" "On"
    rotary 200 "Red" "Green" "Blue" "Yellow"
    choice 200 "Monday" "Tuesday" "Wednesday" "Thursday" "Friday"

    text-list 200 "Monday" "Tuesday" "Wednesday" "Thursday" "Friday"


When other datatypes need to be displayed as text, use the form function 
to convert them first:

    button 250 form now
    field form first read %.
    
===Normal Text Style


Normal text is light on dark and can include a number of facets to 
set the font, style, color, shadow, spacing, tabbing, and other attributes.

    text "Normal"
    text "Bold" bold
    text "Italic" italic
    text "Underline" underline
    text "Bold italic underline" bold italic underline
    text "Big" font-size 32
    text "Serif style text" font-name font-serif
    text "Spaced text" font [space: 5x0]

Text also includes these predefined styles:

    title "Title" 200
    vh1 "vh1"
    vh2 "vh2"
    vh3 "vh3"
    vh4 "vh4"
    label "Label"
    
    
===Document Text Style


Document text is dark on light and can also include a number of facets 
to set the font, style, color, shadow, spacing, tabbing, and other 
attributes.

    txt "Normal"
    txt "Bold" bold
    txt "Italic" italic
    txt "Underline" underline
    txt "Bold italic underline" bold italic underline
    txt "Big" font-size 32
    txt "Serif style text" font-name font-serif
    txt "Spaced text" font [space: 5x0]

Document text also includes these predefined styles:

    title "Centered title" 200
    h1 "Heading 1"
    h2 "Heading 2"
    h3 "Heading 3"
    h4 "Heading 4"
    tt "Typewriter text"
===Text Entry Fields


Text input fields accept text until the enter or tab key is pressed. 
 A text input field can be created with:

    field

To make the field larger or smaller, provide a width:

    field 30
    field 300

Fields will scroll when necessary.


Larger amounts of text can be entered in an area.  Areas also accept 
an enter key and will break lines.

    area

You can also specify the area size:

    area 160x200


To force the text in an area to wrap rather than scroll horizontally, 
provide the wrap option:

    area wrap
===Text Setting


To set the value of a text field under program control, use /text: 
e.g.

    across backtile polished
    return t1: txt      200 "This is some original text"
    return f1: field    200 "Some field text"   
    return a1: area  {Some original area text.} wrap 200x80
    return button 200 "Change Text" [
        t1/text: "Some different text" 
        f1/text: "Some new field text"

        a1/text: {Some wrapping text in the^/ area field to^/ show that this^/ 
        is supported}
        show [t1 f1 a1]
    ]
    
===Text Lists

Text lists are easy to create.  Here is an example.

    text-list "Eureka" "Ukiah" "Mendocino"

You can also provide it as a block:

    text-list data ["Eureka" "Ukiah" "Mendocino"]


Almost any type of block can be provided. Here is a list of all the 
files in your current directory:

    text-list data read %.

Here is a list of all the words REBOL has scanned:

    text-list data first system/words
===Scrolling Text List


A style to allow maintenance of lists from Brett Handley on the REBOL 
list:

        style updatable-text-list text-list
        with [
            update-slider: does [
                sld/redrag lc / max 1 length? head lines
            ]
        ]

        tl: updatable-text-list 300x100 data copy system/locale/months
        button  300x20 "Delete first entry on the list" [
            remove tl/data tl/update-slider show tl
        ]
        button 300x20 "Append the 'now' timestamp to list" [
            append tl/data mold now tl/update-slider show tl
        ]
===Text List Picked Values

    list-of-letters: text-list "a" "b" "c" "d" "e" 
    button 200  "Pick Item 3" [
        clear list-of-letters/picked 

        append list-of-letters/picked pick list-of-letters/data 3 
        show list-of-letters
    ]
===Images

By default an image will be scaled to fit within a face.

    image 60x60 polished
    image polished red

Images can be framed in a number of ways:

    image 100x100 polished frame blue 5x5
    image 100x100 polished bevel
    image 100x100 polished ibevel 6x6

Most other faces can accept an image as well as text:

    box 100x100 polished
    button "Button" polished purple
    toggle "Toggle" polished blue red
    field bold  "This is a field." polished effect [emboss tile]

    field bold "This is another field." polished effect [brighten 100]

The image can be provided as a filename, URL, or image data.



===Backdrops

A backdrop can be a color, an effect, an image, or a combination
of the three.  For example a backdrop color would be written as:

    backdrop navy
    title "Color Backdrop" gold

To create a backdrop effect provide it on the line:

    backdrop effect [gradient 1x1 0.0.100 100.0.0]
    title "Gradient Backdrop" gold

A backdrop image can be a file, URL, or image data:

    backdrop polished
    title "Image Backdrop" red

The backdrop image can be colorized:

    size 400x500 
    backdrop polished blue
    title "Blue Image Backdrop"

The image can include an effect:

    backdrop polished effect [fit gradcol 1x1 100.0.0 0.0.250]
    title "Gradient Image Backdrop"
    
===Backtile

To make a backdrop use a tile effect there are two options:

    backdrop polished effect [tile]
    banner "This shows a backdrop with a tile effect"
    
or

    backtile polished
    banner "This demonstrates backtile"


Note the difference between:

    size 400x500 
    backdrop polished
    banner "Here one image is stretched to cover the canvas"

and

    size 400x500 
    backtile polished
    banner "Here one image is repeated to cover the canvas"
    
===Effect Facets


A range of effects are supported for faces.  All of these effects 
are performed directly on the face when it is rendered. Here are 
examples of a few possible effects in top to bottom then left to 
right order:

    style polished-steel image 80x60 polished 
    polished-steel effect [flip 1x1]
    polished-steel effect [rotate 90]
    polished-steel effect [reflect 1x1]
    polished-steel effect [crop 0x50 120x60 fit]
    polished-steel effect [grayscale]
    polished-steel effect [invert]
    polished-steel effect [difference 200.0.0]
    polished-steel effect [tint 80]
    return
    polished-steel effect [contrast 50]
    polished-steel effect [brighten 50]
    polished-steel effect [sharpen]
    polished-steel effect [blur]
    polished-steel effect [colorize 204.0.0]
    polished-steel effect [gradcol 1x1 150.0.0 0.0.150]
    polished-steel effect [gradmul 0x1 0.100.0]
    polished-steel effect [grayscale emboss]


Effects can be used in combination to create other interesting results. 
 However, keep in mind that the computations are performed in real 
time.  If complex combinations are required, a temporary image should 
be created with the to-image function.


===Actions


An action can be associated with almost any face. To do so, follow 
the face style with a block:

    button "Test" [alert "test"]


The block is used as the body of a function that is passed the face 
and the current value (if the face has one).  For example:

    toggle "Toggle" [alert form value] 
    rotary "A" "B" "C" [alert form value]
    text "Click Here" [alert  face/text]

If a second block is provide, it is used for the alternate
actions (right key):


    button "Click Here" [view/new layout [txt "action"]] [view/new layout 
    [txt "alt-action"]]


Use variables to modify the contents or state of other faces. For 
example, the slider will update the progress bar:

    slider 200x16 [p1/data: value show p1]
    p1: progress

!More action on actions needed...

===Show


After the state is changed for a user interface element, it must 
be re-drawn to be reflected on the user interface canvas.

Accomplish this with the show message.

    backtile polished
    across 
    toggle "Toggle State"  
            [   cybernetics?/data: not cybernetics?/data
                show cybernetics?]  

    return  label "Are you interested in cybernetics?" cybernetics?: 
    check 

One show command can be used for multiple user interface elements

        backtile polished orange
        across
        b1: check label "Red" return
        b2: check label "Green" return

        button 200 "Change State But No Refresh" [b1/data: not b1/data b2/data: 
        not b2/data] return
        button "Show" [show [b1 b2]]
===Hide

A user interface element can also be hidden.

        backtile polished orange
        across
        c1: check 
        hide-button: button "Hide" [hide c1] return
        show-button: button "Show" [show [c1 d2]]


The show-button action tries to show a user interface element 'd2' 
that does not exist.
REBOL/View ignores these.
===Invisible Faces


To make a button invisible when the view is opened, you can define 
an invisible button style

This approach sets the show? value to false when the user interface 
element is initialized.

    across

    style invisible-button button with [append init [show?: false]]
    late-shower: invisible-button "I'm Here" return
    return button 200 "Show Invisible Button" [show late-shower]
    
This works for the other visible user interface element.

===Focus

A user interface element can programmatically be given the focus.

    across backtile polished 
    button 200 "Set focus to Phone Field" [focus f2] 
    return label "Name: "   f1: field 100 
    return label "Phone: " f2: field 100 

    return button 200 "Remove focus from Phone Field" [unfocus f2] 
    return button 200 "Hide the Phone Field" [hide f2] return

---Focus Defect


!Note that the tab function shows a hidden field. I have assumed 
that this is a defect. If a field is hidden, the tab button should 
not make it visible. This has been previously sent to feedback.

===Radio Buttons


A radio button is used to make a choice between mutually exclusive 
values. Your preferred programming language is REBOL or C++ or PL/1 
or APL but it is only one of those.

            across backtile polished

            radio of 'programming-language pad 0x-4 label "REBOL" return

            radio of 'programming-language pad 0x-4 label "C++" return

            radio of 'programming-language pad 0x-4 label "PL/1" return

            radio of 'programming-language pad 0x-4 label "APL" return


To mix two groups of radio buttons on one screen, associate them 
with their groups using the "of 'word". In the above, the grouping 
is 'programming-language.

            across backtile polished

            radio of 'programming-language pad 0x-4 label "Language: REBOL" return

            radio of 'programming-language pad 0x-4 label "Language: C++" return

            radio of 'editor pad 0x-4 label "Editor: TextPad" return

            radio of 'editor pad 0x-4 label "Editor: Notepad" return


The padding in the above is needed to keep the label aligned with 
the radio button.

            across backtile polished orange

            radio of 'programming-language pad 0x-4 label "REBOL" return

            radio of 'programming-language          label "APL" return
            
            
            
            

===Radio Button Settings


A radio button is not very useful unless you can find out what its 
setting is and change that setting under program control.


            across backtile polished orange

            rebol-radio:    radio of 'programming-language  [programming-language: 
            'rebol] pad 0x-4 label "REBOL" return

            apl-radio:      radio of 'programming-language  [programming-language: 
            'apl]         label "APL" return
            button 200 "Toggle radio button" [

                    apl-radio/data: not rebol-radio/data: not rebol-radio/data
                    show [rebol-radio apl-radio]
            ]
            
===Check Box

---Purpose


A check box is used to allow user interface choices where the choices 
are not mutually exclusive.

        across backtile polished orange
        c1: check label "Likes animals" return
        c2: check label "Like Monkees" return
        c3: check label "Like The Animals"
        
---State


A check box is not much good if you can't get and set its state (on 
or off).

        across backtile polished orange
        c1: check label "Likes animals" return
        c2: check label "Like Monkees" return
        
    button "Set State" [
        c1/data: true 
        show c1
        c2/data: false
        show c2
    ]
 
 
===Sensor

---Purpose


A sensor is an invisible user interface element. Using a sensor only 
makes sense in a few instances. 


If you want a keycode action where there is no visible user interface 
element to link the action to then a sensor can be used.


This sensor code adds an Escape or Back or Enter action that will 
close the window. 

    sensor 1x1 keycode [#"^M" #" " #"^(back)" #"^(ESC)"] [unview]


Or if you want to make portions of an image 'hot' instead of putting 
buttons on top of the image, then a sensor will achieve this.

        across backtile polished orange

        txt "Click on the upper left section of the gray image to invoke 
        the sensor action"

        return animage: image 100x100 polished      ; here the image is just 
        the polished area

        at animage/offset sensor 50x50 [alert "You pushed over the sensor"]
        
===Displaying Script Values


If the script has a standard format headings, including custom ones, 
these can be used in the application by picking them from the system/script/header.

        backtile polished
        across banner "About"

        return text font-size 16    rejoin ["Title: "           form system/script/header/title]

        return text font-size 16  rejoin ["Originator: "    form system/script/header/author] 
              

        return text font-size 16  rejoin ["Modifier: "      form system/script/header/modifier]

        return text font-size 16  rejoin ["Version: "       form system/script/header/version]

        return text font-size 16  rejoin ["Updated: "       form system/script/header/date]
        return button "OK" [unview] 

===Toggle


A toggle button represents boolean state - either on or off. The 
button stays down until toggled again.
Colors and text can be paired for "on" and "off" state.

    toggle "Up" "Down" red blue

To set the state via program control, use:

        across backtile polished
        return t1: toggle "Up" "Down" red blue
        return button polished 204.0.0 100 "Toggle State" [
            t1/state: not t1/state
            show t1
        ]


===Rotary Buttons


Rotary buttons are a different sort of user interface device. They 
can cause some challenges because the state is what's showing so 
you have to blindly "toggle" to get to a state that you want.  But 
for quick and easy uses where the user is familiar with the options, 
they can be handy.  If you plan to use them for a long list of items 
such as shown  below, they might give you some usability concerns.


---Example

        across backtile polished
        rotary data ["First" "Second" "Third"]

---Setting State

        across backtile polished

        return r1: rotary data (my-options: ["First" "Second" "Third"])
        return button 200 "Change Rotary State" [
            r1/data: next r1/data
            if tail? r1/data [r1/data: head r1/data]
            show r1
        ]

---Example - Usability For Unfamiliar List Contents


The rotary button demonstrated here contains some information unfamiliar 
to most (Saturn's satellites). Use it to to set the state so that 
"Calypso" is set. Doable but without knowing the order each re-paint 
has to be checked to ensure that it is not "Calypso" before clicking 
again.  If you do click past the choice that you want, there is no 
back function so you have to cycle through again.

        return rotary data [

            "Pan" "Atlas" "Prometheus" "Pandora" "Epimetheus" "Janus" "Mimas" 
            "Enceladus" "Tethys" "Telesto" "Calypso" "Dione" "Helene" "Rhea" 
            "Titan" "Hyperion" "Iapetus" "Phoebe"        
        ]


===Arrows


REBOL/View supports arrows as simple user interface elements. Actions 
can be associated with them.



---Arrowheads And Actions

By default, the arrow is 20x20

    across size 200x100 
    backtile polished
    at 50x50 arrow left 
        [alert "You pressed the left arrow"] 

        [alert "You pushed the alternate button on the left arrow"] 
    at 70x30 arrow up
    at 90x50 arrow right [alert "You pressed the right arrow"]
    at 70x70 arrow down
    
---Very Sharp Arrows


And with a little work the arrows and boxes can be merged to look 
sharper. Here is a "sharp at both ends" arrow from the block diagram 
script by Carl:

    origin 0
    backcolor white
    at 0x0 box 40x40 white effect [arrow rotate 270]
    at 110x0 box 40x40 white effect [arrow rotate 90]
    at 24x10 box black 100x20
    
---Arrow Blend

So that shows you how to make an arrow blend into your background

    size 100x100
    across backdrop gray
    at 50x50 box 40x40 gray effect [arrow rotate 90]
    at 40x67 box 25x5 black
    
===LED

LEDs would be used to display state (on or off).  

Clicking the LED toggles its state and changes its color.

LEDs do not support alternate mouse button actions.

    across banner "Light Emitting Diode"
    return 

    l1: led 10x10 [alert "LED left mouse action"] label "Alert status"

    l2: led 10x10 [alert "LED left mouse action"] label "Network status"
    return button "Change state" [
        l1/data: not l1/data
        l2/data: not l2/data 
        show [l1 l2]        
    ]
    
===Box


---Boxing

Draw boxes of any heigth and width with the box style

    box "Large Box" 200x400 polished orange
    
---Boxes As Lines


If you make the box narrow enough or short enough it is a line (or 
a dot).

    across size 300x300 backtile polished
    at 50x0 box 3x100 gold
    at 0x50 b1: box 100x3 gold
    at 10x10 box 5x5 red
    
---Boxes Can Grow

    across size 300x300 backtile polished
    at 150x0 b1: box 100x3 gold
    return pad 0x100 button "Grow Down" [
        for i 3 300 1 [
            b1/size/y: 1 + b1/size/y
            wait 00:00:00.01
            show b1
        ]
    ]

    return pad 0x100 button "Back Up" [
        for i 300 3 -1 [
            b1/size/y: b1/size/y - 1
            wait 00:00:00.01
            show b1
        ]
    ]

You might even find a use for it.


---Grid Effect

Not sure of the use for this yet but here is what you can do:


 return box "Grid Lock" with [effect: [grid 20x20 8x8 4x3]] white 
 300x200
 

 return box "Grid Lock" with [effect: [grid 20x20 5x5 3x3]] white 
 - 80 300x200
 
===Frame

Earlier versions of REBOL VID supported frames in layouts such as
view layout [frame "This is the Bay" %bay.jpg]

These are no longer valid.

But frames can be put around some user interface devices:

    image 100x100 polished frame red
    
===List


A list is an iterated sub layout and takes a layout block that uses 
the Visual Interface Dialect. The styles in the layout will be repeated 
until there is no more room to fit them within the list dimensions.


---Why


A face can be iterated to create a number of virtual faces. For instance, 
when displaying a list of ten buttons, each of the buttons does not 
need to be created as a separate object. If the buttons only differ 
by a few facets (such as position, text, and action taken on selection), 
a model face can be created and iterated for its other position. 
This is useful when creating scrolling lists of files and other data 
sets that share the same appearance. 

---Supply


Supply provides the data to the list for an iterated face.

    do [cnt: 0
        list-collection: [aqua sky water]    
    ]
    backtile polished orange
    across
    list-displayed: list 100x72 [
        origin 0 space 0x0 across
        color-field: txt bold 80x24
    ] supply [
            if none? one-color: pick list-collection count [exit]
            face/text: do pick [one-color] index

    ]

    return txt gold 180 "OK ... but not too useful"


---Supply Columns

Maybe adding some more columns would be better.

Here I'll add a column of buttons that display the color name
and a column of text strings in italic.

    do [
        cnt: 0
        list-collection: [aqua sky water gold silver coffee]    
    ]
    backtile polished orange
        across
        list-displayed: list 300x200 [
            origin 0 space 0x0 across
            color-field: txt bold 80x24
            color-button: button 80x24
            pad 5x1
            txt 100 italic
        ] supply [

                if none? one-color: pick list-collection count [exit]
                face/text: do pick [
                    [one-color]
                    [to-string one-color]
                    [rejoin ["  " to-string one-color]]
                    ] index 
    ]
    

    return txt gold 300 {A bit more interesting but the last row repeats 
    to fill the list size. Some of the other VID components will automatically 
    stretch to fit the size needed (such as this txt field) but the list 
    does not behave that way.  You have to make the list size fit its 
    data or make it smaller and add a vertical scroll capability. That 
    is shown a little later on.}

===List With Supplied Data

This example is to show adding action to the list
and adds a horizontal line between the rows.


    do [
        cnt: 0
        list-collection: [aqua sky water gold silver coffee]    
    ]
    backtile polished orange
        across

        list-displayed: list water edge [size: 6x6 color: silver]  350x96 
        [  
            origin 0 space 0x0 across

            color-field: txt 60 [alert rejoin ["You pressed the " face/text " 
            text field"]]
            pad 45x0            

            color-button: button 80 [alert rejoin ["You pressed the " face/text 
            " button"]]
            pad 5x0
            txt 120 italic

            return box 350x1 white      ; this causes a horizontal line to appear 
            between each row

        ] supply [

                if none? one-color: pick list-collection count [exit]
                face/text: do pick [
                    [one-color]
                    [to-string one-color]
                    [rejoin ["  " to-string one-color]]
                    ] index 
    ]


===Supply List With Scroll

This example shows a supplied list with a scroll capability.
More colors are added to demonstrate scrolling.

Note that this is a verbose list of code where I added comments
for my understanding of how the scroll was linked to the list.
The same effect can be accomplished with fewer lines of code.
    

    do [    ; first this do block creates the data definitions needed.
        slider-position-clicked:  0
        count: 0    
        x: 450
        y: 300

        row-y: 16           ; the row height includes the data plus any separator 
        lines 

        list-size: to-pair reduce [x y]     ; this is the size of the display 
        list  
        separator-size: to-pair reduce [x 1]
        slider-size: to-pair reduce [24 y ]
        list-collection: [

            aqua           bar-color   base-color     beige         black    
                  blue           brick          brown      

        button-color   coal        coffee         crimson       cyan     
              forest         gold           gray       

        green          ivory       khaki          leaf          linen    
              magenta        main-color     maroon     

        mint           navy        oldrab         olive         orange   
              over-color     papaya         pewter         

            pink           purple      rebolor        red           sienna   
                  silver         sky            snow

        tan            teal        violet         water         wheat    
              white          yellow        
        ]    
        
        supply-style: stylize [

                button-fixed: button left coal to-pair reduce [80 row-y]        ; 
                these keep the row elements the same height

                text-fixed: txt to-pair reduce [160 row-y]          
        ]
        
        data-size: length? list-collection  
    ]
    

    backtile polished orange                        ; this section layouts 
    out the list
        
        across

        list-position: at                                   ; the position 
        is captured here in order to later put the slider beside it
        list-displayed: list linen 
            edge [size: 6x6 color: tan]  list-size [  
            origin 0 space 0x0 across
            styles supply-style

            text-fixed [alert rejoin ["You pressed the " face/text " text field"]]

            button-fixed [alert rejoin ["You pressed the " face/text " button"]]
            pad 5x0 

            text-fixed 80 italic [alert rejoin ["You pressed the italic " face/text 
            " text field"]]

            return box separator-size gray      ; this causes a horizontal line 
            to appear between each row

        ] supply [
                count: count + slider-position-clicked  

                if none? one-color: pick list-collection count [exit]
        face/text: 
            either count > (1 + data-size) 
            [""]
            [
                             do pick [

                                    [one-color]                                                      
                                           ; this is supplied to the first txt field (text-fixed)

                                    [to-string one-color]                                           ; 
                                    this is supplied to the button (button-fixed)

                                    [rejoin ["  " to-string one-color " "]]     ; this value is supplied 
                                    to the last text-fixed field
                            ] index 
                    ]
        ]


        ; now add a slider to the side of the list



        at list-position + (list-size * 1x0)                             
           ; this finds the top right border of the list widget
        vertical-slider: slider slider-size to-integer y / row-y
        [

                    slider-position-clicked: vertical-slider/data   ; the slider has 
                    to be bound to the size of the list                

                        * ((1 + data-size) - ((y / (1 + row-y))))       ; including the row 
                        height
                    if slider-position-clicked <> count [
                        count: slider-position-clicked 
                        show list-displayed
                    ]
                ]


===Slider


A slider is interactive user interface element. The data of a slider 
varies from 0 to 1.

    backtile polished   orange across
    slider-1: slider 200x40 
    return button 200 "Move first slider to 50%" [
        slider-1/data: .5 
        show slider-1
    ]

    return txt 200 "The second slider in this example is initialized 
    to the 80% mark."  
    return slider 200x40 with [append init [data: .8]]
    
===Progress Indicator


The progress-1 face in this example is a progress indicator. Because 
it is only displaying information, it is non-interactive i.e. you 
can not change its value by dragging its edges.  The alternate button 
is not supported on a progress indicator.

    backtile polished   orange across
    slider 200x40 [
        progress-1/data: value 
        field-1/text: join (to-integer (100 * value)) " %"
        show [progress-1 field-1]
    ] 
    return progress-1: progress
    return field-1: field
===Panels 


Panels are used to create sub-panes that can be more easily managed 
by grouping

the user interface devices on a panel. The first example below shows 
how to use panels for layout alignment. By creating a panel definition, 
all of the components defined within it are aligned relative to its 
origin.

    across backtile polished brick
    tabs 50
    return panel-1: panel 250x120 [
        backtile polished
        across
        return button water 200 "Button A"
        return button aqua  200 "Button B"
        return button sky   200 "Button C" 
    ]


    at panel-1/offset + panel-1/size panel 60x90 [  ; start at the bottom 
    right corner of panel-1
        backtile polished
        across
        return button tan       20 "1"
        return button coffee    20 "2"
    ]
    
---Multiple SubPanels example


This example from the REBOL html documentation shows how to easily 
hide and show sections of a user interface by displaying them on 
the face area of a box.  


        do [                                ; define two panels
            panel1: layout [
                    origin 8x8
                    h2 "Panel 1"
                    field "Field 1"
                    field "Field 2"
                    button "The Answer" [alert "I know nothing."]
            ]


            panel2: layout [
                origin 8x8
                    h2 "Panel 2"
                    across
                    txt "X:"
                    slider 150x16
                    return
                    txt "Y:"
                    slider 150x16
                    return
                    check [panel2/color: maroon  show panel2]
                    txt "Don't click this"
                    return 
                    check [panel2/color: silver  show panel2]
                    txt "Click this" 
                    return
                ]

                panel1/offset: 0x0
                panel2/offset: 0x0
        ]


        vh2 "Subpanel Examples"     ; now demonstrate panel use
        guide
        pad 20
        button "Panel 1" [panels/pane: panel1  show panels]
        button "Panel 2" [panels/pane: panel2  show panels]
        button "Quit" [unview]
        return
        box 2x140 maroon
        return
        panels: box 220x140
        do [panels/pane: panel1]
        
===Simple Default Style Override


The style's default look can be overriden easily with one line of 
code. 


For example, to make the default button size 200x200 with a water 
color, use

    style button button 200x200 water
    button "Big Blue Button" [unview]

To make the toggle some different default colors:

    style toggle toggle crimson sky
    toggle "Up" "Down"


Note that these stay in effect until they are overridden so if you 
use the default values, exercise some care unless you meant to do 
that. 



===Image Maker


An option used by Carl in some of his programs is to let View create 
specific icons so that you have portability and more control of look 
of the image then if you referenced an external file such as gif 
that was a bullet display. Here's how to do that:

    do [    
        make-image: func [xy wh eff] [
            eff: layout [
                size 20x20 at xy
                box wh effect eff
            ]
        eff/color: rebolor
        to-image eff
        ]


        dot: make-image 6x5 9x9 [gradient 1x1 255.0.0 0.0.0 oval key 0.0.0]

        dot-big: make-image 8x7 12x12 [gradient 1x1 255.0.0 0.0.0 oval key 
        0.0.0]
        arr: make-image 3x3 14x14 [arrow 0.0.127 rotate 90]
        ard: make-image 3x3 14x14 [arrow 0.0.127 rotate 180]    

    ]   ; end of "do" - it is needed here because easyvid approach is 
    expecting vid dialect commands

    banner "Presentation Points"
    size 400x300 across

    style label label gold     ; make a label's text be a different color 
    than the default
    return image dot label "This is bullet point number 1" 
    return image dot label "This is bullet point number 2"
    return image arr label "This is arrow point number 1"

    return image ard label "This is an arrow making a different point"

    return image dot-big pad 0x4 area 300x80 wrap "And because these 
    arrows and dots are images, action can be added to them to make them 
    'hot' with mouse actions including 'over'."
    
===Needs Some Work

!More to come.  These still need to be covered in this
tutorial:

    text-list data [
        icon
    ]
    
===Digital Clock

    origin 0
    banner "00:00:00" rate 1 effect [gradient 0x1 0.0.150 0.0.50]

        feel [engage: func [face act evt] [face/text: now/time  show face]]


 


===REBOL Logo

 image %rebo-logo.gif [unview]

===Paint Drops

REBOL one liner by Vincent Ecuyer


 b: box rate 9 effect[draw[pen(random snow)circle(random 99x99)2]blur]box 
 1x1 rate 9 effect[draw[(b/image: to-image b)]]
 
===eMailer

One line emailer by Doc Kimbel

Assumes you have set up your email in set-user



 e: field "Email" s: field "Subject" m: area "Body" btn "Send"[send/subject 
 to-email e/text m/text s/text alert "ok"]
 
===Hello World

 text "Hello World!" button "Close" [unview]
===Three Buttons

 button "Yes" button "Maybe" button "No"

===View Web Text

 text 800x600 read http://www.rebol.com
 
===View Image

 image %palms.jpg
 
===View Image and File Name


Here a do block is used to initialize the file variable within the 
layout code.

 do [file: %palms.jpg]
 image file  text form file
 
 
===View Image behind File Name


Here a do block is used to initialize the file variable within the 
layout code.

 do [file: %palms.jpg]

 image file form file
 
 
===Buttons From Images

    backdrop 40.70.140
    stat: text bold "Click a Button" 100x20 240.140.40 center
    button "Bay Test"  %bay.jpg 100x100 [
        stat/text: "Upper" 
        show stat
    ]
    button "Blue Test" %bay.jpg 100x100 10.30.180 [
        stat/text: "Lower" 
        show stat
    ]
===View List


 list blue 320x200 [across text white 200 text white 100] data [
    ["John" 100] 
    ["Joe" 200] 
    ["Martin" 300]
 ]
===Movie Credits



    backdrop %bay.jpg effect [fit]

    text center bold 240x30 "REBOL, The Movie" yellow font [size: 16]
    credits: text {

 Edit This File 

 To Add Your Own Credits 
 

 It is very simple to do. 

 Only takes a minute. 

 Only REBOL Makes It Possible...

 } white bold center 240x180 rate 30 para [origin: 0x+100]
        feel [engage: func [f a e] [

            if a = 'time [f/para/origin: f/para/origin - 0x1 show f]
        ]
    ]



===Fire Demo

    box 150x150 with [
        edge: none
        img: image: make image! 150x150
        rate: 20
        text: "FIREBOLEK"
        font: make font [size: 24 color: 255.125.0]

        basic: [draw [image make pair! reduce [(random 3)  - 2 -1] img]]
        effects: reduce [
            append copy basic [blur luma -10]
            append copy basic [sharpen luma -10 blur]
            append copy basic [contrast 10 blur luma -5]        
        ]
        effect: first effects
        feel: make feel [
            engage: func [f a e][
                switch a [

                    down [f/effects: next f/effects if tail? f/effects [f/effects: head 
                    f/effects] f/effect: first f/effects show f]

                    time [show f repeat i f/size/x - 4 [poke f/image (f/size/x * f/size/y) 
                    - i - 2 (random 255.0.0 + random 0.127.0) * 3] f/img: to-image f] 
                           
                ]       
            ]
        ]
    ]
    text 150 {classical fire demo for REBOL^/
 press on fire to see other effects.^/   
 Written by ReBolek, 2001 in 15 mins.^/
 We need new category on Assembly:^/
 less-than-kb-demo ;-)} with [font: make font  [size: 9]]
===Bezier 

Oldes Bezier Line Demo

See script library for %bezier-curve.r

Uses functions and data initialized at script startup

The end points are draggable to change the curve!!!!


Here a do block is used to allow executable lines for initialization 
purposes.

 do [

    draw-beziere-curve: has [result pp x0 x1 x2 x3 y0 y1 y2 y3 cx bx 
    ax cy by ay t tx ty s] [
    result: make block! 120
    pp: p0/size/x / 2
    x0: p0/offset/x + pp
    y0: p0/offset/y + pp
    x1: p1/offset/x + pp
    y1: p1/offset/y + pp
    x2: p2/offset/x + pp
    y2: p2/offset/y + pp 
    x3: p3/offset/x + pp
    y3: p3/offset/y + pp

    insert result compose [
        pen 155.0.0
        line (p0/offset + pp) (p1/offset + pp)
        line (p2/offset + pp) (p3/offset + pp)
        pen 255.255.255 line (p0/offset + pp)
    ]    
    cx: 3 * (x1 - x0)
    bx: 3 * (x2 - x1) - cx
    ax: x3 - x0 - cx - bx
    cy: 3 * (y1 - y0)
    by: 3 * (y2 - y1) - cy
    ay: y3 - y0 - cy - by
    
    t: s: 0.01 ;this value sets quality of the curve
    
    while [t <= 1][
        tx: to integer! (

                (ax * (t * t * t)) + (bx * (t * t)) + (cx * t) + .5
            ) + x0
        ty: to integer! (

                (ay * (t * t * t)) + (by * (t * t)) + (cy * t) + .5
            ) + y0

        t: t + s
        insert tail result to pair! reduce [tx ty]
    ]
    return result
 ]


 click?: false
 mouse-pos: 0x0


 ]

    origin 0

    bkg: box black 400x400 with [effect: reduce ['draw make block! 120]]
    style point box 10x10 with [

        effect: [draw [pen 0.255.0 fill-pen 0.200.0 circle 4x4 4]]
        changes: [offset]
        feel: make feel [
            engage: func [f a e][
                if a = 'down [click?: on mouse-pos: e/offset]
                if a = 'up   [click?: off]
                if find [over away] a [
                    if click? [
                        f/offset: f/offset + e/offset - mouse-pos
                        bkg/effect/2: draw-beziere-curve
                        show [bkg f]
                    ]
                ]
            ]
        ]
    ]
    at 300x200 p0: point
    at 200x100 p1: point
    at 200x300 p2: point
    at 100x200 p3: point
    do [bkg/effect/2: draw-beziere-curve]
                   
===Buttons Galore

Buttons galore from the library script %buttons.r


Here a do block is used to execute the initialization needed within 
the layout block.



    do [
        group: ["rotary" "test" "button"]
    ]

    origin 20x10
    backdrop effect [gradient 0x1 100.20.0]

    vh1 "52 Button Click-up - Each with a different click effect..."

    vtext bold "Here is a small sampling of the thousands of button effects 
    you can create. (This is 78 lines of code.)"
    at 20x80 guide
    button "simple"
    button form now/date
    button "colored" 100.0.0
    button "text colored" font [colors: [255.80.80 80.200.80]]
    button with [texts: ["up text" "down text"]]
    button "bi-colored" colors [0.150.100 150.20.20]

    button with [texts: ["up color" "down color"] colors: [0.150.100 
    150.20.20]]
    button "image" pic
    button "color image" pic 200.100.50

    button "flip color" pic with [effects: [[fit colorize 50.50.200][fit 
    colorize 200.50.50]]]
    button "blink" with [rate: 2 colors: [160.40.40 40.160.40]]
    return

    button "multiply" pic with [effects: [[fit][fit multiply 128.80.60]]]
    button "brighten" pic with [effects: [[fit][fit luma 80]]]

    button "contrast" pic with [effects: [[fit][fit contrast 80]]]
    button "horiz flip" pic with [effects: [[fit][fit flip 1x0]]]

    button "vert reflect" pic with [effects: [[fit][fit reflect 0x1]]]
    button "invert" pic with [effects: [[fit][fit invert]]]

    button "vert grad" with [effects: [[gradient 0x1 0.0.0 0.200.0] [gradient 
    0x1 0.200.0 0.0.0]]]

    button "horiz grad" with [effects: [[gradient 1x0 200.0.0 200.200.200][gradient 
    1x0 200.200.200 200.0.0]]]

    button "both grad" with [effects: [[gradient 1x0 140.0.0 40.40.200] 
    [gradient 0x1 40.40.200 140.0.0]]]

    button "blink grad" with [rate: 4 effects: [[gradient 1x0 0.0.0 0.0.200] 
    [gradient 1x0 0.0.200 0.0.0]]]

    button "blink flip" pic with [rate: 8 effects: [[fit][fit flip 0x1]]]
    return
    button "big dull button with several lines" 100x80 0.0.100

    button "dual color" pic 50.50.100 100.50.50 100x80 with [edge: [color: 
    80.80.80]]

    button "big edge" pic 100x80 with [edge: [size: 5x5 color: 80.80.80] 
    effects: [[fit colorize 50.100.50][fit]]]

    button "oval reflect" pic 50.100.50 100x80 with [effect: [fit reflect 
    1x0 oval]]
    return

    button "text on top" pic 100x80 with [font: [valign: 'top] effects: 
    [[fit gradcol 1x1 200.0.0 0.0.200] [fit gradcol -1x-1 200.0.0 0.0.200]]]

    button "text on bottom" pic 100x80 50.50.100 with [font: [valign: 
    'bottom] effects: [[fit][fit invert]]]

    button "big text font" pic 100x80 with [font: [size: 24] effects: 
    [[fit multiply 50.100.200][fit]]]

    button "cross flip" pic 50.100.50 100x80 with [effect: [fit flip 
    0x1 reflect 0x1 cross]]
    return
    toggle "toggle"
    toggle "toggle red" 100.0.0 
    toggle "toggle up" "toggle down"
    toggle "toggle colored" 0.150.100 150.20.20
    toggle "up color" "down color" 0.150.100 150.20.20

    toggle "toggle multiply" pic with [effects: [[fit][fit multiply 128.80.60]]]

    toggle "toggle contrast" pic with [effects: [[fit][fit contrast 80]]]
    toggle "toggle cross" pic with [effects: [[fit][fit cross]]]

    toggle "toggle v-grad" with [effects: [[gradient 0x1 0.0.0 0.200.0] 
    [gradient 0x1 0.200.0 0.0.0]]]

    toggle "toggle h-grad" with [effects: [[gradient 1x0 200.0.0 200.200.200][gradient 
    1x0 200.200.200 200.0.0]]]

    toggle "toggle both" with [effects: [[gradient 1x0 140.0.0 40.40.200] 
    [gradient 0x1 40.40.200 140.0.0]]]
    return
    rotary data group
    rotary data reduce [now/date now/time]
    rotary data group 100.0.0 0.100.0 0.0.100

    rotary data group with [font: [colors: [255.80.80 80.200.80]]]
    rotary data group with [colors: [0.150.100 150.20.20]]
    rotary data group pic
    rotary data group pic 200.100.50

    rotary data group pic with [effects: [[fit colorize 50.50.200][fit 
    colorize 200.50.50]]]

    rotary data group with [effects: [[gradient 0x1 0.0.0 0.200.0] [gradient 
    0x1 0.200.0 0.0.0]]]

    rotary data group with [effects: [[gradient 1x0 200.0.0 200.200.200][gradient 
    1x0 200.200.200 200.0.0]]]

    rotary data group with [effects: [[gradient 1x0 140.0.0 40.40.200] 
    [gradient 0x1 40.40.200 140.0.0]]]
===Paint Program


This section is a clip of the layout portion of Frank Sievertsen's 
remarkable paint program. Open this example to enable a quick link 
to the real source:


 button "Browse Source" [browse http://www.reboltech.com/library/html/paint.html]
 button "Close" [unview]


In the example below, a DO block is used to execute initialize code.

 do [

    color: fill-color: start: draw-image: draw-pos: tmp: none
    type: 'box
    undos: [] redos: []
    draw: func [offset /local tmp] [
        compose [
            pen (color/color) fill-pen (fill-color/color)
            (type) (start) (either type = 'circle [
                tmp: offset - start
                to-integer square-root add tmp/x ** 2 tmp/y ** 2
            ] [offset])
        ]
    ]
 ]
 
        backdrop effect compose [gradient 1x1 (sky) (water)]
        across
        draw-image: image white 300x300 effect [draw []]
        feel [engage: func [face action event] [
            if all [type start] [
                if find [over away] action [
                    append clear draw-pos draw event/offset
                    show face
                ]
                if action = 'up [
                    append/only undos draw-pos
                    draw-pos: tail draw-pos
                    start: none
                ]
            ]
            if all [type action = 'down] [
                start: event/offset
            ]
        ]]
        do [draw-pos: draw-image/effect/draw]
        guide
        style text text [
            tmp: first back find face/parent-face/pane face
            tmp/feel/engage tmp 'down none
            tmp/feel/engage tmp 'up none
        ]
        label "Tool:" return
        radio [type: 'line] text "Line"
        return
        radio [type: 'box] on text "Box"
        return
        radio [type: 'circle] text "Circle"
        return
        style color-box box 15x15 [

            face/color: either face/color [request-color/color face/color] [request-color]
        ] ibevel
        color: color-box 0.0.0 text "Pen"
        return
        fill-color: color-box text "Fill-pen"
        return
        button "Undo" [if not empty? undos [
            append/only redos copy last undos
            draw-pos: clear last undos
            remove back tail undos
            show draw-image
        ]]
        return
        button "Redo" [if not empty? redos [
            append/only undos draw-pos
            draw-pos: insert draw-pos last redos
            remove back tail redos
            show draw-image
        ]]
===Font Lab

Carl's Font lab



Here a do block is used to initialize some values needed in the layout

 do [

    change-styles: func [style start facet subfacet value /local v][
    start: find style/pane start
    foreach f start [
        f: in f facet
        if subfacet <> 'none [f: in get f subfacet]
        either block? value [

            if not block? get f [set f either none? get f [copy []][reduce [get 
            f]]]

            either v: find get f value [remove v][head insert get f value]
        ][set f value]
    ]
    show style
 ]

 chg: func ['facet 'subfacet value] [
    change-styles external-view norm-start facet subfacet value
 ]
 shad: does [chg font shadow sdir * to-integer sl2/data * 16]
 sdir: 1x1
 sz: 180x40
 sx2: sz/x / 2 
 ]



    style tgl toggle 60
    style lab vtext bold
    backcolor rebolor
    space 0x5
    across 

    p: choice 180 "Sans-Serif Style" "Serif Style" "Fixed Width Style" 

        [chg font name pick reduce [font-sans-serif font-serif font-fixed] 
        index? p/data]
        return
    tgl "Bold" [chg font style [bold]]
    tgl "Italic" italic [chg font style [italic]]
    tgl "Lined" underline [chg font style [underline]]
    return
    tgl "Left" of 'tg1 [chg font align 'left]
    tgl "Center" of 'tg1 [chg font align 'center]
    tgl "Right" of 'tg1 [chg font align 'right]
    return
    tgl "Top" of 'tg2 [chg font valign 'top]
    tgl "Middle" of 'tg2 [chg font valign 'middle]
    tgl "Bottom" of 'tg2 [chg font valign 'bottom]
    return
    lab "Size:" 60x20 font []

    sl: slider 120x20 [chg font size max 8 to-integer sl/data * 40] 
     with [append init [data: .5]]
    
    return
    lab "Space:" 60x20 font []

    sl1: slider 120x20 [chg font space (1x0 * to-integer sl1/data * 20) 
    - 5x0]
    return
    lab "Shadow:" 60x20 font []
    sl2: slider 120x20 [shad]  with [append init [data: .5]]
    return
    lab "Shad Dir:" 60x20
    arrow left  [sdir: sdir * 0x1 + -1x0 shad] pad 6
    arrow right [sdir: sdir * 0x1 + 1x0 shad]  pad 6
    arrow up    [sdir: sdir * 1x0 + 0x-1 shad] pad 6
    arrow down  [sdir: sdir * 1x0 + 0x1 shad]  pad 6
    return
    button sx2 "Text Color" [chg font color request-color]
    button sx2 "Area Color" [chg color none request-color]
    return

    button sx2 "Help" [alert "Click the controls on the left to change 
    text on the right."]
    button sx2 "Close" #"^Q" [unview]
    below
    at p/offset + (p/size * 1x0) + 10x0
    norm-start:
    Title "Title" sz
    h1 "Heading 1" sz
    h2 "Heading 2" sz
    h3 "Heading 3" sz
    h4 "Heading 4" sz
    h5 "Heading 5" sz
    at norm-start/offset + (norm-start/size * 1x0) + 10x0
    banner "Banner" sz
    vh1 "Video Heading 1" sz
    vh2 "Video Heading 2" sz
    vh3 "Video Heading 3" sz
    vtext "Video Text" sz
    text "Document Text" sz
    

===Windows Clipboard


---Cut or Copy to Clipboard


Normal Windows cut and copy commands are supported e.g. on a field, 
contents can be copied to the clipboard. Programmatic access is also 
supported for text contents.

    across 
    label "Entry field: "
    return input-field: field 200 "Enter your text here"

    return button 200 "Copy Entry field data to clipboard" [write clipboard:// 
    input-field/text]

    return button 200 "Show Clipboard Contents" [alert read clipboard://] 


---Clearing The Clipboard


    across 
    button 200 "Clear The Clipboard" [write clipboard:// ""]

    return button 200 "Show Clipboard Contents" [alert read clipboard://] 



---Paste from Clipboard


Normal Windows paste commands are supported e.g. on a field, contents 
can be pasted. Programmatic access is also supported for text contents.

    across 

    button 200 "Show Clipboard Contents" [alert read clipboard://] 
===Requesters


REBOL View supports an assortment of requesters. 


The results of the request-* code are returned as its value e.g. 
chosen-date: request-date


---Request Yes | No | Cancel


Provides the user the capability to pick from choices "Yes" | "No" 
| "Cancel"

The result is "True" | "False" | none

    do [user-response: none]

    button "Simple Request" 200 [user-response: request "Do you want 
    to abandon your input so far?"]
    button "View User Response" 200 [alert form user-response]
    

---Pick A Color

    do [chosen-color: gold] 
    button "Pick Color" 200 [chosen-color: request-color]
    button "View Chosen Color" 200 [alert form chosen-color]



---Pick An Answer

The request allows a descriptive value then 1, 2, or 3 options.


    button "Format" 100 [request ["Your message goes here. It will wrap 
    if it is very very long." "Choice 1" "Choice 2" "Choice 3"]]
    

    button "Example 1" 100 [request ["Pick The Color of Your New Model 
    T" "Black"]]
    

    button "Example 2" 100 [request ["Pick one country" "England" "France"]]


    button "Example 3" 100 [request ["Run Extract Script?" "Yes" "No" 
    "Cancel"]]


---Pick A Date

    do [chosen-date: 01-Jun-1990]
    button "Pick Date" 200 [chosen-date: request-date]
    button "See Chosen Date" 200 [alert form chosen-date]

---Get A LogonID and Password

    do [credentials: none]
    button "Get Credentials" 200 [credentials: request-pass]
    button "View Credentials" 200 [
        view/new layout [
            size 200x200 backtile polished orange 
            across banner "Credentials" 
            return label "LogonID:  " txt pick credentials 1
            return label "Password: " txt pick credentials 2
        ]
    ]


---Pick A File


Format: REQUEST-FILE /title title-line button-text /file name /filter 
filt /keep    

        do [filter-block: ["*.gif" "*.jpg" "*.png" "*.bmp"]]

        button "Pick Any File" 300 [request-file "Select"]      

        button "Pick With A Title" 300 [request-file/title "Pick The Data 
        File to Process" "OK"]

        button "Change the Action Button Name" 300 [request-file/title "Pick 
        The Data File to Process" "OK"]        

        button "Keep Results" 300 [request-file/title/keep "Previous Select 
        On This Button Is Kept" "OK"]

        button "Filter Files" 300 [request-file/title/filter "Pick An Image 
        File" "OK" filter-block]    



---Request Text Input

Format: REQUEST-TEXT /offset xy /title title-text /default str
    

    button "Request Text Input - all default parameters" 300 [request-text]

    button "Request Text Input - with offset to window" 300 [request-text/offset 
    40x40]

    button "Request Text Input - with title" 300 [request-text/title 
    "Input your question"]

    button "Request Text Input - with default" 300 [request-text/default 
    "Key your question here"]

    button "Request Text Input - with all parameters" 300 [request-text/offset/title/default 
    100x100 "Input your question" "Key your question here"]



---Request Download from Net


Request a file download from the net. Show progress. Return none 
on error.

Format: REQUEST-DOWNLOAD url /to local-file

    backtile polished orange    

    button "Request File Download To local REBOL Cache" 300 [request-download 
    http://www.rebol.com/index.html]

    button "Request File Download To This Directory" 300 [request-download/to 
    http://www.rebol.com/index.htmlnone]

    button "Request File Download To Specific File" 300 [request-download/to 
    http://www.rebol.com/index.html%/c/temp.html]

===Message Box


    button "Format" 100 [request ["Your message goes here. It will wrap 
    if it is very very long and tedious." "Close"]] 
    button "Example" 100 [request ["You done good!" "OK"]]



---Confirmation

    button "Exit" 100 [
        request/confirm "Do you want to quit without saving?" []
    ]
    

===Calling the Editor

The REBOL editor is now callable with the editor function

    backtile polished
    button 300 "Create a test file and edit it" [
        write %temp.txt "This is a test file"
        editor %temp.txt
    ] frame 204.0.0 
    

===Calling Windows

With View/Pro the calling of executables is supported.

Here are two simple examples that will work if you have View/Pro 
on a platform where a notepad and calc are avaiable.

    across backtile size 200x200
    return button "Notepad" [call ["notepad.exe"]]
    return button "Calculator" [call ["calc.exe"]]


===Window Options


Note that these are options which are ignored by the easyvid.r code 
that displays them in this tutorial.
Copy the code out and run it standalone in REBOL/View.

---Block Options: No Border and No Title

    view/options layout [
        size 200x200 
        banner "Window Options" 
        button "Close" [unview]
        ] [
            no-border
            no-title
        ]


---Word Option: No Title


Note that the results of this are surprising if you run it from within 
a script that has a title option. It is displayed near location 0x0 
of the resulting window instead of in the window frame that has been 
suppressed. 

    view/options layout [
        size 200x200 
        banner "Window Options" 
        button "Close" [unview]
        ] 'no-title

===REBOL/View Notifiers


REBOL/View supports simple notifiers to send messages to a user interface


---Alert

    button 220 polished "Send alert message" [
        alert "This causes a dialogue box to popup"
    ]





---Flash

Flash is provided to provide a message and keep on processing.

    across size 200x200
    return button 150 "Create Flash Message" [flash "Testing"]
    return button 150 "Unview Flash" [unview]



---Inform

    inform layout  [
        backtile polished sky 

        across text font-size 16 bold underline red "Action complete!" 
        return button "OK"  [unview]]

---Popup

REBOL supports popups  (see note below before running!)

        across size 200x200 
        button "Show Popup" [
            show-popup popup-layout: layout [
                    across size 200x200 
                    backtile polished
                    banner "The Popup Worked" 
                    return button "Unview" [unview]
                ]
        ]
        return button "Hide Popup" [unview/only popup-layout]

I have had some difficulties (process lockup) when using

these popups so just use view layout [...] and skip the popup part.

===Diagram Example


Carl has created some diagrams in REBOL using styles to make an architecture 
diagram.

This is a slightly modified version.


Here again a DO block precedes the layout code for non-layout initiatiation 
... here the definition of a function.

Why make a diagram this way?


1. One reason is that it can be interactive ... the sections are 
all "hot" with a few lines of code.  Here they pop up REBOL Dialogs 
but they could do anything that can be coded even something as simple 
as launching a browser on a different URL for each diagram component. 
 The "Compositor" box demonstrates this by launching your browser 
on the REBOL.com site.


2. Very small footprint size compared to other presentation source 
formats.




 do [
        information: func [info [string!]][
        request/ok reform [ info]
    ]
 ]



    style bx box 255.255.255 0.0.0 font-size 11 font [color: 0.0.0 shadow: 
    0x0] edge [size: 5x2] 
        [request/ok reform ["No information on" face/text]] 

    style bb box bold left top para [origin: 6x10] edge [size: 2x2]
        [request/ok reform ["No information on" face/text]]
    backcolor silver + 30
    at 15x15 h1 486 left "Arch Structure" 
    at 15x50    bb "Client" 506x436 160.80.80 [

        information "Any client machine e.g. branch or Call Centre"]

    at 25x252   bb "Mid-Tier" 486x68 effect [gradient 1x1 169.91.155 
    80.45.75]

    at 25x152   bb "UI" 486x96    effect [gradient 1x1 38.156.82 19.78.41]

    at 25x324   bb "Servers" 486x151   effect [gradient 1x1 103.96.200 
    50.45.100] [

        information "Mid-tiers servers with XYZ relational database server" 
                                                                         
              
    ]

    at 130x216  bx "Compositor" 182x24 bold [browse http://www.rebol.com]

    at 130x60   bx "Browser" 120x24 [information "Branch standard browser"]

    at 130x188  bx "Sound" 182x24 bold [information "Sound services"]
    at 255x60   bx "Win32" 120x24 [information "Win32 App"]

===Column Images


Creates a layout looking (a little) like columns. It uses a gradient 
effect going from darker to lighter

 do [
     column: make image! layout [

            backdrop effect [gradient 1x0 20.20.20 250.240.230 luma 60]
        ]

    column-size: 50x420

    area-size: 400x420  ; height should be the same as column-size
 ]
 backtile polished tan
   across 
   image column-size  column 
   pad -10x0        ; this brings the default VID spacing back
   area wrap area-size  

   edge none        ; take the edge off of area so that it more closely 
   blends 
   shadow 2x2

   pad -10x0 image column-size column  ; if you want a right column

===Tree View of Directory

This is Didier's tree view %request-dir.r


In this sample, you must be online because the code is accessed on 
the Rebol script server

 do [do http://www.rebol.org/library/scripts/request-dir.r
     request-dir
 ]


Note that:

* the script is read from the script library but runs locally

* it is showing the files in your directories


===The emailer Function


The function for emailing has appeared in Jan-2004 on the rebol list.


It is a simple idea ... to create a standard emailer by invoking 
a function emailer. This window will show the source:

  text wrap 400x300 mold get 'emailer

And it is simple to run:

    across size 200x200
    return button 150 "Run emailer" [emailer]


But on my machine there is again a problem - the emailer locks up 
REBOL/View.

Recommendation:

* if it works use it if you like


* use Doc Kimbel's one liner (works for me). Assumes you have set 
up your email in set-user



 e: field "Email" s: field "Subject" m: area "Body" btn "Send"[send/subject 
 to-email e/text m/text s/text alert "ok"]



* better yet, make your own... if the code for the basic is 1 line, 
then a custom version is not far away. Here's an example that allows 
selection of your frequent contacts (entered in the names-addresses 
series) and keeps a journal of email that you have sent (using this 
code) in file email-journal.txt.  Assumes you have setup your user 
profile correctly to allow sending of email.


 do [

  names-addresses: [
    "Contact 1"         [contact1-:-no-such-address-:-com]
    "Contact 2"         [contact2-:-no-such-address-:-com]
    "Contact 3"         [contact3-:-no-such-address-:-com]
  ]

  names: copy []
  foreach [name address] names-addresses [append names name]


  journal?: false  ; set to true if want to journalize sent email
 ]

    e: rotary 200 data sort names
    s: field "Subject" 
    m: area 500x400 wrap "Body" 
    btn "Send"[

        send/subject who-to: select names-addresses e/text m/text s/text 
        alert join "Sent email to: " form who-to
        
        if journal? [
            write/append %email-journal.txt rejoin [
                "[ When-sent: " now/precise 
                " To: " who-to
                " Subject: {" s/text
                "} Message: {" m/text "} ] "
                newline
            ]
        ]
    ]
    btn "Quit" [unview]



It won't take much to change this from the rotary used to a text 
list allowing multiple selections.





===Some More email


Earlier there have been a few examples of sending email. Here are 
a few more that often appear in the mailing list

---Simple Send


This is not a runnable version because you don't need anything but 
REBOL/Core to run it. It has been wrapped in a DO block so it does 
not send errors to the console.

---Quick Send Short Message

 do [
    send [address-:-isp-:-com] "My Message"
 ]
 
---Send Longer Message  

Now a more complex message where there is a body to the message:

 do [
    send [address-:-isp-:-com] {Sample Message
               
    This is the body of the message
    } 
 ]

---Send with One Attachment


Here, so that the sample does not fail, test file(s) are created 
by the code before attempting the send. 

 do [
    test-file: %file-attachment.txt
    write test-file {Just some test data to create a file}
    send/attach [address-:-isp-:-com] {Sample Message
               
    This is the body of the message
    } test-file
 ]
 
---Send with Attachments

And a message with multiple attachments.


Here, so that the sample does not fail, test file(s) are created 
by the code before attempting the send. 

 do [
    files: [%file-attachment.txt %second-attachment.txt]

    foreach file files [write file {Just some test data to create a file}]
    send/attach [address-:-isp-:-com] {Sample Message
               
    This is the body of the message
    } files
 ]
 
---Send to Multiple Addresses


Here, so that the sample does not fail, test file(s) are created 
by the code before attempting the send. 

 do [
    files: [%file-attachment.txt %second-attachment.txt]

    foreach file files [write file {Just some test data to create a file}] 

    send/attach [[address-:-isp-:-com][asecondAddress-:-isp-:-com]] {Sample Message
               
    This is the body of the message
    } files
 ]
 
---Send/only

Same send only just provide the SMTP server with one copy:

Here, so that the sample does not fail, test file(s) are created 
by the code before attempting the send. 

  do [
    files: [%file-attachment.txt %second-attachment.txt]

    foreach file files [write file {Just some test data to create a file}] 

    send/only/attach [[address-:-isp-:-com][asecondAddress-:-isp-:-com]] {Sample 
    Message
               
    This is the body of the message
    } files
 ]
 
---Send With Header


This example uses a Do block to wrap the code. If you execute the 
email should be sent.
But it is unlikely to be delivered.


The addresses for me and you should be changed in your use as well 
as the

* Subject

* Organization

* Content 

 do [
   me: [myaddress-:-isp-:-com]
   you: [youraddress-:-isp-:-com]
   header-object: make system/standard/email [
            From: me
            Reply-To: me
            Subject: "Some Stuff"
            Organization: "Cyberia"
            MIME-Version: 1.0 
            Content-Type: "text/plain"
    ]
 send/header you {Test Message
    This is the message body.
    }                 
    header-object 
 ] 

---Send with CC

This adds a copy value in the header-object

 do [
   me: [myaddress-:-isp-:-com]
   you: [youraddress-:-isp-:-com]
   header-object: make system/standard/email [
            From: me
            Reply-To: me
            Subject: "Some Stuff"
            Organization: "Cyberia"
            MIME-Version: 1.0 
            Content-Type: "text/plain"
        cc: [another-address-:-isp-:-com]
    ]
 send/header you {Test Message
    This is the message body.
    }                 
    header-object 
 ] 


   
---Doctored Code

Again Doc Kimbel's one liner that does not waste a character


 e: field "Email" s: field "Subject" m: area "Body" btn "Send"[send/subject 
 to-email e/text m/text s/text alert "ok"]


===Sharp Styles


I really like the style that Didier has put around his email previewer

 do [
    ss-light: stylize [
        text: text feel none
        vtext: vtext feel none
        col-hdg: text black 255.255.204 bold middle effect []
        col-txt: text edge [size: 1x0 color: gray effect: 'bevel]
        ban: vh3 left to-pair reduce [
            50 logo.gif/size/y] edge [

                color: 0.0.0 size: 0x1] feel none with [color: black]
        lab: label para [origin: 2x3 margin: 0x2]
        labe: lab edge [size: 1x1 color: water effect: 'ibevel]
        inf: info 100 font-color yellow
        bkg: backdrop water - 10.10.10
        txt-big: vtext 300 font-size 18 font-color yellow center
        rti: vtext font-size 14 bold
        txt-ch: rti font-color white 170x22 para [
            origin: 2x3] with [font: make font [
                    color: white] colors: [55.95.155 235.170.55]]
        btnb: btn 70.70.70 font-color white

        men: rti 264 edge [size: 1x1 color: water effect: 'bevel] para [origin: 
        20x2 margin: 1x4]

             with [color: water - 40.40.40 effect: first effects: [

                [draw [pen white fill-pen white polygon 5x2 13x10 5x18]] [draw [pen 
                white fill-pen white polygon 2x5 10x13 18x5]]
             ] feel: none]  ;system/view/vid/vid-feel/hot]

        cbox: box 60x20 edge [size: 1x1 color: water effect: 'bevel] [

            if temp: request-color/color first face/data [face/color: temp change 
            face/data temp show face]
        ] with [append init [color: first data]]
    ]
    stylesheet: ss-heavy: stylize/styles [

        col-hdg: col-hdg effect [gradcol 0x1 200.200.160 155.155.104]

        ban: ban effect [merge gradcol 150.180.200 0.0.0] with [color: none]

        bkg: backdrop effect [gradient 1x1 65.125.175 45.75.115 grid 2000x4 
        1999x4 70.130.190 blur]
        txt-big: vtext 300 font-size 18 font-color yellow center
        rti: vtext font-size 14 bold

        txt-ch: txt-ch effect [gradcol -1x1 105.105.105 151.151.151]
        men: men effect [gradcol -1x0 black water]
    ] ss-light
 ]
    styles stylesheet
    space 4x4 origin 4x4 across
    bkg
    pad 15 ban 235 :title para [origin: 32x0]
    pad -254
    image 30x30 %palms.jpg effect [fit key 255.0.255]
}
code: text: layo: external-view: none
sections: []
layouts: []
space: charset " ^-"
chars: complement charset " ^-^/"

rules: [title some parts]

title: [text-line (title-line: text)]

parts: [
      newline
    | "===" section
    | "---" subsect
    | "!" note
    | example
    | paragraph
]

text-line: [copy text to newline newline]
indented:  [some space thru newline]
paragraph: [copy para some [chars thru newline] (emit txt para)]
note: [copy para some [chars thru newline] (emit-note para)]
example: [
    copy code some [indented | some newline indented]
    (emit-code code)
]

section: [
    text-line (
        append sections text
        append/only layouts layo: copy page-template
        emit h1 text
    ) newline
]
subsect: [text-line (emit h2 text)]
emit: func ['style data] [repend layo [style data]]
emit-code: func [code] [
    remove back tail code
    repend layo ['code 460x-1 trim/auto code 'show-example]
]
emit-note: func [code] [
    remove back tail code
    repend layo ['tnt 460x-1 code]
]

show-example: [

    if external-view [xy: external-view/offset  unview/only external-view]
    xcode: load/all face/text
    if not block? xcode [xcode: reduce [xcode]] ;!!! fix load/all
    if here: select xcode 'layout [xcode: here]
    external-view: view/new/offset layout xcode xy
]

page-template: [
    size 500x480 origin 8x8
    backdrop white - 80

    style code tt snow navy bold as-is para [origin: margin: 12x8]
    style tnt txt maroon bold
]

parse/all detab content rules
show-page: func [i /local blk last-face][
    i: max 1 min length? sections i
    append clear tl/picked pick sections i 
    if blk: pick layouts this-page: i [
        f-box/pane: layout/offset blk 0x0 
        last-face: last f-box/pane/pane    ; bh slider

    f-box/pane/pane/1/size: f-box/pane/size: max 500x480 add 20x20 add 
    last-face/offset last-face/size ; bh slider
    update-slider ; bh slider
        show f-box
    ]

    show tl    ; changed to after slider update ; was not refreshing 
    the index display
]


update-slider: does [
    sld/data: 0
    either object? f-box/pane [
        sld/redrag min 1.0 divide sld/size/2 f-box/pane/size/2
        sld/action: func[face event] compose [

            f-box/pane/offset/2: multiply face/data (subtract 480 f-box/pane/size/2)
            show f-box
        ]
    ][
        sld/redrag 1.0 show sld
        sld/action: none
    ]
    show sld
]

main: layout [
    backtile polished
    across
    vh2 title-line return
    tl: text-list 160x480 bold black white data sections [
        show-page index? find sections value
    ]
    h: at
    f-box: box 500x480

  at h + 500x0 sld: slider 24x480                 ; add brett's slider
    at h + 456x-24
    across space 4
    arrow left  keycode [up left] [show-page this-page - 1]
    arrow right keycode [down right] [show-page this-page + 1]
    pad -150

    txt white italic font-size 16 form system/script/header/date/date
]

show-page 1
xy: main/offset + either system/view/screen-face/size/x > 900 [
    main/size * 1x0 + 8x0][300x300]
view main

If I have a block of datatype shouldn't I be able to do?:

find blk datatype!

I would think we would want to be able to find out if a block contains 
a datatype given that we might not know what the datatype is if it 
is populated dynamically.

I looked around a bit and couldn't really find a good solution.  
Is there an easy way to reorder a block that's not sorting it - To 
just move one element.  Say my-block: [a b c d e]  Is there a function 
to just move c to the front of the block, or to push it to the back?

i have about 50,000 word strings in a single block.  I would like 
to do a find/any wordsblock "sear?ch*" ;on it but no go - am i missing 
some fundamental feature of Core or is this broken?

I know :-) I guess you have to wonder what result you want back, 
because it has to search each string in the block. what you are looking 
for is a find on each string in the block and what if that is not 
found in the beginning? Does it return two indexes, one for the string 
and one for the block? That's where /deep comes in.

Why is it, that b is not auto-bound to the function in this example?

>> f: func [b code] [do code]
>> f "hi" [print b]
** Script Error: b has no value


I mean, passing [print b] as an argument to the function, it's just 
a block of words without meaning initially. When handed to f, f takes 
over and will now do it. So f has to find out, what's the meaning 
of the inside of the block. First it finds the word "print", which 
makes sense. Then it find the word "b", and this doesn't makes sense 
to f. Why not?

From !REBOL3 group, following MattAnton's fbionacci func.


Matt, it's a good func, but there are some things to watch out for 
in REBOL, which are different from many other languages.


1) Undeclared vars in func become global. Use the /local refinement 
to declare them.


2) Series values in funcs (e.g. your starting block of [0.0 1.0] 
maintain their value between calls if you don't use COPY. Run your 
function multiple times to see what happens. It may be that you wanted 
this to be a memoizing function, but then why UNSET 'fibonacci-block?.


I think you also mentioned that the challenge was to do it recursively, 
which this isn't. That's a case where you would definitely want to 
memoize. :-)


In any case, this is always fun stuff to think about.  Here's a modified 
version for you to play with. Look at some of the other REBOL funcs 
used, see if you find any bugs, or maybe it will give you ideas for 
other ways to solve the problem.

fibonacci: func [

    "Returns a list of fibonacci numbers, up to the specified count."
	count [integer!] "Number of iterations to run"
	/trace
	/local res n-1 n-2 incr step
] [
    incr: func [word] [set word 1 + get word]
    step: does [incr 'n-1  incr 'n-2]
	res: copy [0.0 1.0]
	set [n-1 n-2] [1 2]
	repeat i count [
		append res add pick res n-1 pick res n-2
		step
		if trace [print [i last res]]
    ]
    res
]
print mold fibonacci 3
print mold fibonacci 46

A hash is a block optimsed for 'find
A list is a block optimised for 'insert and 'append
Hash is very likely to be replaced by something else in R3
A note from Gregg about using list:
http://www.rebol.org/ml-display-thread.r?m=rmlQFPC

As for the clearing of the locals  from a function - here you go:

clear-locals: func [

        {Used as the ending statement within a function to set the function's 
        locals to none value.}
        fnc [function!]
    ][

        set bind first to-block trim/with mold first :fnc "/" first find 
        second :fnc set-word! none
]

Besides it works find it I didn't use the loop  to populate the block.

BACKPORTS! Hot off the presses! Get your new R3 functions, now here 
for R2! Available now, before the next release!

funct: make function! [
    [catch]
    "Defines a user function assuming all set-words are locals."

    spec [block!] "Help string (opt) followed by arg words (and opt type 
    and string)"
    body [block!] "The body block of the function"
    /local r ws wb a
][
    spec: copy/deep spec
    body: copy/deep body
    ws: make block! length? spec
    parse spec [any [

        set a [word! | refinement!] (insert tail ws to-word a) | skip
    ]]
    wb: copy ws
    parse body r: [any [
        set a set-word! (
            unless find wb a: to-word a [insert tail wb a]
        ) |
        hash! | into r | skip
    ]]
    unless empty? wb: difference ws wb [
        remove find wb 'local
        unless find spec /local [insert tail spec /local]
        insert tail spec wb
    ]
    throw-on-error [make function! spec body]
]

functor: make function! [
    [catch]

    "Defines a user function with all set-words collected into a persistent 
    object (self)."

    spec [block!] "Help string (opt) followed by arg words (and opt type 
    and string)"
    body [block!] "The body block of the function"
    /local r wb a

][ ; Note: Words in the spec override the bindings of the object 
words.
    wb: copy []
    parse body r: [any [
        set a set-word! (unless find wb a [insert tail wb a]) |
        hash! | into r | skip
    ]]
    remove find wb [self:]

    throw-on-error [make function! copy/deep spec  bind/copy body construct 
    wb]
]

>> b: 'test   ;; line gets evaluated , b already holds a word!
== test
>> append a :b  ;; word get's added to serries
== [test]
>> type? first a
== word!

>> find a 'test  ;; 'test get's evaluated into a word again so find 
finds it in block
== [test]

>> c: ['test]      ;; 'test is in a block and of course doesn't get 
evaluated as any other thing in a block wouldn't so it stays lit-word!
== ['test]

if you want a block to get evalueated you should reduce it, then 
it will also find it

I think its a good idea to ahve find like that (so that it gives 
subset) but expression would have to be a block so you can put any 
code inthere and things are systematic

of course it would be nice to have something like find/all which 
returns a block of all the occurences

I'm using to highlight parts of strings in a face during a text search. 
so I need to find caret offsets for each and append to the face/effect/draw 
block

the numbers for the  FIND can be supplied from a copy of the block 
with UNIQE

same result using find-remove:

foreach z a [if find a reduce [z] [remove a reduce [z]]]

I get three left over blocks


i I run it again I get one left over block and f I run it a final 
time it reoves the final block

foreach will advance to the next index whether or not the series 
was modified:
>> D: [1 2 3 4 5 6 7 8 9]
== [1 2 3 4 5 6 7 8 9]
>> foreach X D [remove find D X]
== []
>> ? D
D is a block of value: [2 4 6 8]

Chris wrote: "G: re. confused - try stepping through the function 
in the order it is interpreted.  Should be clear by the time 'use 
evaluates the two blocks..."


What I find a bit confusing is, when I have to BIND and when I don't. 
It's the context binding rules in REBOL, that is not 100% clear to 
me. Let me give a simple example:

>> b: [print i]
== [print i]
>> f: has [i] [i: 1 do b]
>> f
** Script Error: i has no value


This doesn't work, because the b block is defined outside the f function, 
outside f's function context. Therefore I have to bind b to f's context, 
like this:

>> f: has [i] [i: 1 bind b 'i do b]
>> f
1


That is clear, and I would expect USE to work by the same rules, 
but it doesn't quite, it seems to me:

>> f: does [use [i] [i: 1 do b]]
>> f
1


By some magic, this works without the need to BIND. I'm a bit confused 
by that.

A non-parse solution (for the replace problem) based on the existing 
replace mezz:

replace-each: make function! [
	target [series!] "Series that is being modified"
	values [block!] "Block of search/replace strings"
	/local len pos
][
	foreach [search replace] values [
		len: length? search
		while [pos: find target search] [
			target: change/part pos replace len 
		]
	]
]

A new idea for the Bindology article enhancement: for a given BLOCK 
and CONTEXT find out, whether the block is in the given context or 
not. Do you think, that such a function might be interesting?

the same goes for /first (find first occurance in a block of multiple 
targets ... a long planned feature)

I wouldn't say We MUST add /SAME to FIND, though it could be useful 
in special cases. Another posssibility, though I want to think about 
it more before standing behind it, would be to allow AT to take an 
index value that is a reference. Hmmm, no, maybe not. It would then 
have to return NONE if the item wasn't in the block. Nevermind.

You could tweak something like this:
    res: make block length? blk
    while [ind: find blk 23]
         [print blk append res index? ind blk: skip blk last res]
    blk: head blk
    probe res


But remember the first rule of REBOL Code Golf: parse always wins.....We're 
now just waiting for a parse guru to show us how :)

indices?-1: func [
	series [series!]
	value
	/local result
] [
	result: make series 0
	while [series: find series value] [
		append result index? series
		series: next series
	]
	result
]

indices?-2: func [
	series [series!]
	value
	/local result
] [
	result: make series 0
	parse series [

  any [1 1 value series: (append result subtract index? series 1) | 
  skip]
	]
	result
]
>> time-block [indices?-1 blk 23] 0,05
== 0.000006591796875

>> time-block [indices?-2 blk 23] 0,05
== 0.000005645751953125

Still this is too slow.. it's fine for 1M data, but 10M and it grinds 
hard.

.. there must be a faster way to find integers in a block (or hash) 
using SELECT, FIND or INDEX?

yes... you do a find, within a while block.   that was the fastest 
loop I did for matching exact SAME? strings.  I'd bet its the best 
here too.

Is there something like "unmold"? I find myself needing to return 
a molded block back to a block all the time.

User friendliness
 is in the eye of the beholder. I consider this:

>> block: [none #[none] true #[true] 0.1 0.10000000000000002]
>> print mold/all block

[none #[none] true #[true] 0.10000000000000001 0.10000000000000002]
>> print mold block
[none none true true 0.1 0.1]


as a problem for me, trying to give me wrong informations, as well 
a a problem for a beginner, who may not even be able to find out 
the informations he obtained were wrong

svv/vid-styles/button/multi/block: func [face blk][ ; <- This only 
does BUTTON for now.
	if pick blk 1 [
		;face/action: func [face value] pick blk 1

  face/action: func [face value /local window word] compose/only [

   window: face/parent-face ; Find the window face <-- (simplistic for 
   now)

   word: window/pane/1/var ; Find a word which references a field in 
   the window. <-- (simplistic for now)
			print "Remake action function."

   face/action: func [face value] probe append append copy [bind-funcs] 
   to-lit-word word (pick blk 1)
			do-face face value
		]

  if pick blk 2 [face/alt-action: func [face value] pick blk 2] ; <- 
  Also need to remake alt-action similarly to action, above.
	]
]
bind-funcs: func [word] [

 foreach window-function [hello][bind second get window-function word]
]

hello: does [f/text: copy "hello" show f]

open-window: does [
	view/new center-face layout ctx: vid-context [
		f: field
		button "Hello" [hello]
		button "Clear" [clear-face f]
	]
]

open-window
open-window
do-events

svv/vid-styles/button/multi/block: func [face blk][ ; <- This only 
does BUTTON for now.
	if pick blk 1 [
		;face/action: func [face value] pick blk 1

  face/action: func [face value /local window word] compose/only [

   window: face/parent-face ; Find the window face <-- (simplistic for 
   now)

   word: window/pane/1/var ; Find a word which references a field in 
   the window. <-- (simplistic for now)
			print "Remake action function."

   face/action: func [face value] probe append append copy [bind-funcs] 
   to-lit-word word (pick blk 1)
			do-face face value
		]

  if pick blk 2 [face/alt-action: func [face value] pick blk 2] ; <- 
  Also need to remake alt-action similarly to action, above.
	]
]
bind-funcs: func [word] [

 foreach window-function [hello][bind second get window-function word]
]

hello: does [f/text: copy "hello" show f]

open-window: has [window ctx] [
	window: view/new center-face layout vid-context/to [
		f: field
		button "Hello" [hello]
		button "Clear" [clear-face f]
		button "Clear window2's field" [clear-face window2/user-data/f]
	] 'ctx
	window/user-data: ctx
	window
]

window1: open-window
window2: open-window
do-events

Graham -- consider using a Trie

[that is more-or-less what skimp.r does, but the skimp data structures 
are badly disorted as I was struggling to find a deeply-nested block 
structure that did not trigger garbage collection bugs in the then-current 
REBOL core. (those bugs have been fixed)]
   http://en.wikipedia.org/wiki/Trie

sorry if I will propose a nonsense, or if the solution already exists, 
but - when using REBOL for data extraction (using parse) and forming 
a block or CSV as a result, I often come to the need of append-only-if-the-item-does-not-exist-already, 
so using following idiom:

if not found? find target value [append target value]


What about adding /not refinement (or other name), so that I could 
append only unique values?

Also - is there any way of how to easily find out, if the block is 
unique? Should I apply 'unique, and compare the length before and 
after? Pity 'unique has /skip refinement, but does not have /compare 
one (as 'sort has), so that I can't set, when I have e.g. record 
of 5 items, I want to 1) set the record size (/skip) 2) select fields, 
upon which we want to define uniquess - could be an integer offset, 
or a block of positions [1 3] ... 'sort allows at least the offset 
via /compare

I found not use ALTER as it's not native.. I usually use the solution 
UNIQUE where the block is not much large, but if efficiency is needed, 
I would just go with:

unless find blk val [append blk val]

HI again. I was wondering how you would approach this matter: I have 
a block of objects (all the same type - they are records of first 
name, last name, unique id, etc) I want to find the index of a particular 
object by unique id. I usually just go through a loop and check each 
object's id for a match and that works but is there a better way? 
 Thanks.

So, mostly, if you work with SQL, you try to find the right context 
of data, limiting your query as much as possible. Then you do a query, 
receive result and browse it. In that case, you already have all 
your data in rebol block already (unless you are reading them from 
port continuously), and it has nothing to do with SQL database anymore 
...

To change data, you could do:
clear next find face/effect/draw 'line
append face/effect/draw data-block

view/new layout [
	the-field: field feel [

		use [body at-key-block key-block][

			; copy the engage function body

   body: copy/deep second get in svv/vid-styles/field/feel 'engage


   ; modify the copy to move the block with the EDIT-TEXT word in it
			; to a new IF then-block
			at-key-block: next find select body [switch act] [key]
			key-block: at-key-block/1

   change/only at-key-block compose/only [probe event/key if true (key-block)]

			; make the new function
			engage: func [face act event] body

		]

	]
]
focus the-field
do-events

view/new layout [
	the-field: field feel [

		use [body at-key-block key-block][

			; copy the engage function body

   body: copy/deep second get in svv/vid-styles/field/feel 'engage


   ; modify the copy to move the block with the EDIT-TEXT word in it
			; to a new IF then-block
			at-key-block: next find select body [switch act] [key]
			key-block: at-key-block/1
			change/only at-key-block compose/only [
				if find "-0123456789.^H^-" event/key (key-block)
			]

			; make the new function
			engage: func [face act event] body

		]

	]
	new-field: field
]
focus the-field
do-events

Hi Rebolinth, there's a compromise between the low-level MAKE FACE 
and the LAYOUT [] approach for single faces called MAKE-FACE. It's 
basically a way to create single faces using the VID style name and 
a spec block for of specifying facets. Of course, MAKE FACE should 
have the lowest overhead, whereas - just as it says - LAYOUT is more 
for describing whole layouts. You may find MAKE-FACE slightly easier 
to create VID-compatble faces without getting into too much detail.

if error? program-error: try [
  view layout [
    h3 "Avoid the console from popping up"

    box 500x100 "Hold down left mouse button and drag to create errors" 
    feel [
      engage: func [face act evt] [
        if find [over away] probe act [
          2 / 0 ; error!
        ]
      ]
    ]
  ] do-events
] [
  ; what to do here to block the events from the view window?
  error-obj: disarm program-error
  inform layout [
    h3 "Program Error!"
    area 300x200 mold error-obj
    button "Close"
  ]
]

system/schemes/system: make object! [
    name: 'system
    title: "System Port"
    spec: none
    info: none
    actor: make native! [[port!]]
    awake: make function! [[
        sport "System port (State block holds events)"
        ports "Port list (Copy of block passed to WAIT)"
        /local event port waked
    ][
        waked: sport/data
        loop 8 [
            if not event: take sport/state [break]
            port: event/port
            if wake-up port event [
                if not find waked port [append waked port]
            ]
        ]
        if not block? ports [return none]
        forall ports [
            if find waked first ports [return true]
        ]
        false
    ]]
    init: make function! [[port][
        port/data: copy []
    ]]
]

For my previous snippet:

>> layout [X: button]

X is just a generic variable name I use when I need a throwaway, 
like others use "foo", "bar", and so on.  Layout is just assigning 
the button object to the word X, which I'm exploring in the next 
few lines like Geomol explained.


I explored system in the same way to find view, then VID, then vid-styles. 
 vid-styles is a block containing a series of alternating names and 
definitions, which the foreach loop is simply going over

you will find it in the RebGUI directory on xpeers

 ... got it the first time, just making sure I was looking at the 
 most current version. FYI, tooltips had me baffled for a long time 
 (they worked for you, consumed tons of CPU for me) until I realized 
 they were only a problem with the new tab-panel implementation ... 
 which now stores all tabs in a pane and uses the show? attribute 
 to work out which one is visible or not (the original stored hidden 
 tabs in a data block). The fix was simple, change the tooltip code 
 to ignore faces with show?: false.

strip tree widget from drop-tree

 ... the tree widget I'm working on is similar to text-list but with 
 leading triangles (indented by level) that toggle between sideways 
 (close leaf) and down (open leaf). Not sure whether Cyphre's one 
 is based on the same [simple] concept.

Can we somehow align while you do RebGUI 2?

 ... as discussed previously (see post from 10-Mar), with the key 
 points being:


 1) Use (and possible extension) of global UI settings (colors, sizes, 
 effects, behaviors) in %rebgui-ctx.r

 2) Widgets should define a 'rebind func if they need to change a 
 statically bound UI setting (e.g. color)
	3) Use the new tab-panel widget

and a fourth:


 4) Layout uses 'tip (not 'tooltip) to specify the widget's tip string!


Note that the current build has had most widget-specific exceptions 
removed, especially from %rebgui-edit.r; and that /dialog (hence 
popup) code has been rewritten to support true modal dialogs (that 
can in turn call additional modal dialogs). The later improvements 
are courtesy of recent REBOL/VIew popup changes.

As append-widget removal was oversimplification imo, especially for 
the widget authors, I created short script, which kind of automates 
the process ....

1) Save the script, e.g. make.r, into the RebGUI root dir

2) create one file, called %my-widget-list.r, containing unnamed 
block, containing file-names. Your widgets can be placed anywhere

3) create backup of %rebgui-widgets.r, call it %rebgui-widgets.old.r, 
in order to be able to easily "remove"  widgets by commenting them 
out in file 2)

Here's the script:
REBOL []

;--- to enable removal of unwanted own widgets, create
;--- copy of rebgui-widgets.r into rebgui-widgets.old.r

;--- remember to do so, when official distro release contains new 
widgets!
if exists? %rebgui-widgets.old.r [
  write %rebgui-widgets.r read %rebgui-widgets.old.r
]

;--- load list of widgets you want to include
;--- file containing un-named block of list of files to include
widgets-to-include: load %my-widget-list.r

template: "^-#include %widgets/^/"

;--- read RebGUI widget list (%rebgui-widgets.r)
tmp: read %rebgui-widgets.r

widget-buffer: copy "^/"

foreach widget-filepath widgets-to-include [ 

   widget: last split-path widget-filepath

   ;--- copy widget to the widget-directory
   write join %widgets/ widget read widget-filepath
  
   ;--- build string containing widget names you want to add ...

   ;--- but only when not already on the list - prevent duplicate entries
   if not found? find tmp widget [

        append widget-buffer (head insert find/tail copy template "/" widget)
   ]

]

;--- append to RebGUI widget-list (%rebgui-widgets.r)
change back back tail tmp (append widget-buffer "]")
write %rebgui-widgets.r tmp

;--- rebuild RebGUI distribution ...
call "create-distribution.r"

Graham - either syntax works.  I had been testing several events 
(away, over, etc.) and Ashley's documentation mentions that you can 
put them all inside a single "on [...]" block.

I find I can refer to my parent table easily with a short path, by 
just doing "insert clear tbl/data ...." from the child window "Save" 
button action and I get what I want.  BUT, that means I didn't encapsulate 
my table name at all like I had hoped within my adddelusers object. 
 I would like to setup each window display with generic widget names, 
and not worry about uniqueness - that's why I thought about trying 
to wrap the guis in objects.  Can that be done?  and if so, will 
I be back to my problem of not knowing how to reference an encapsulated 
widget on another window?

Thanks!

Question: How useful would you find the following, and what other 
aggregate funcs would you find most useful? 

fold: func [
	block [any-block!] "Block of values"
	accum "Accumulator value" 
	f [any-function!] "Function to apply"
][
    foreach val block [accum: f :accum :val]
]
sum: func [block [any-block!]] [fold block 0 :add]
product: func [block [any-block!]] [fold block 1 :multiply]
average: func [block [any-block!]][
    if empty? block [return none]
    divide  sum block  length? block
]

I think I used it like this:
	if not find block item [alter block item]

Hi Anton, did you 'source 'alter?

alter: func [

    {If a value is not found in a series, append it; otherwise, remove 
    it.} 
    series [series! port!] 
    value 
    /local temp
][

    either temp: find series value [remove temp] [append series value]
]

So, you'd better off with:

if not find block item [append block item]

But if you need it, you can use something like that:
alter-count: func[
	block [any-block!]
	value [any-type!]
	/local temp count
][
	either temp: find/tail/skip block :value 2 [
		change temp count: temp/1 + 1
		count
	][
		append block reduce [:value 1]
		1
	]
]
(the name of the function should be probably different)

one-liner version:
alter-count: func[
	block [any-block!]
	value [any-type!]
][

 pick change block: any [find/tail/skip block :value 2 insert tail 
 block :value] 1 + any [block/1 0] -1
]

I tried to run the fledgling Rebol.org test suite against the public 
alpha to get a first impression of the impact of the changes in R3.


The first stumbling block is that RUnit (run.r) accesses system/error
  

I looked in DocBase but couldn't see any reference to the "new" System 
object. Any hints on where to find documentation on the changes to 
the system object?

I thought you might be curious to see how FUNCT works. It's very 
useful:

>> source funct
funct: make function! [[
    {Defines a user function assuming all set-words are locals.}

    spec [block!] {Help string (opt) followed by arg words (and opt type 
    and string)}
    body [block!] "The body block of the function"
    /local ctx
][
    spec: copy/deep spec
    body: copy/deep body
    ctx: make object! 4
    bind/set body ctx
    unless find spec /local [append spec /local]
    append spec words-of ctx
    make function! reduce [spec body]
]]

Ok, I'm building it of several parts. (This may change if I find 
some more clever way of doing it.) First there is a DATA-GRID, which 
is a TIGHT style that contains actors to generate a grid view and 
links to a block of data. DATA-GRID is a slave style in that you 
link it to a data block and then it will display what it can display 
of that block from a start index set in the style, so it works like 
a data window. TEXT-GRID is currently just a variant of DATA-GRID 
with different spacing between cells.


Next, we can move that start index around by attaching a scroller 
to the DATA-GRID, and set the DATA-GRID's ON-SCROLL actor to set 
a new index, based on the input from the scroller. The scroller will 
be set based on the size of the data block versus the size of the 
data grid. Presto, a functioning list view.

I will explain sorting, filtering and all that later.

Here's the current source for LOAD:

load: func [
	{Loads a file, URL, or string.}
	source [file! url! string! any-block! binary!]

 /header  {Includes REBOL header object if present. Preempts /all.}

;	/next    {Load the next value only. Return block with value and 
new position.}

;	/library {Force file to be a dynamic library. (Command version)}
;	/markup  {Convert HTML and XML to a block of tags and strings.}
	/all     {Load all values. Does not evaluate REBOL header.}
	/unbound {Do not bind the block.}
	/local data tmp
][
	; Note: Avoid use of ALL func, because of /all option
	if any-block? :source [return :source]

	data: case [
		string? source [to-binary source]
		binary? source [source]
		; Check for special media load cases: (temporary code)
		find [%.jpg %.jpeg %.jpe] suffix? source [
			return load-jpeg read/binary source
		]

  url? source [read source] ; can this possibly return not binary! 
  ?
		file? source [read source] ; binary! or block of file!
	]

 ; At this point, data is binary!, a block of file!, or something 
 weird.

	if binary? :data [
		unless find [0 8] tmp: utf? data [
			cause-error 'script 'no-decode ajoin ['UTF tmp]
		]

		; Only load script data:
		if any [header not all] [ ; Note: refinement /all
			if tmp: script? data [data: tmp]
		]
	]

	unless block? :data [data: to block! :data] ; reduce overhead

 ; data is a block! here, unless something really weird is going on
	tmp: none
	
	; Is there a REBOL script header:
	if any [header not all] [ ; /header preempts /all
		tmp: unless any [

   ;not any [file? source url? source] ; removed: hdr in string is same
			unset? first data ; because <> doesn't work with unset!
			'rebol <> first data
			not block? second data
		][ ; Process header:
			attempt [construct/with second data system/standard/script]
		]
		; tmp is header object or none here
		case [
			tmp [
				remove data
				either header [change data tmp][remove data]
				tmp: tmp/type = 'module ; tmp true if module
			]
			header [cause-error 'syntax 'no-header data]
		]
	]
	; tmp is true if module, false or none if not

 ; data is a block!, with possible header object in first position

	; Bind to current global context if not a module:
	unless any [
		unbound
		tmp ; not a module
	][
		bind/new data system/contexts/current
	]

 ; data is a block! here, unless something really weird is going on

	; If appropriate and possible, return singular data value:
	unless any [ ; avoid use of ALL
		all
		header ; This fixes a design flaw in R2's LOAD
		;not block? :data ; can this ever happen?
		empty? data ; R2 compatibility
		not tail? next data
	][data: first data]
	; If /all or /header, data is a block here

	:data
]

SELECT works on object! and map! but FIND doesn't. PICK and POKE 
work, but they take keys rather than indexes. There are some (at 
this point undocumented) limits on what can be used as keys too (at 
least you can't use a block as a key in practice), but that may be 
a bug.

something related, in the past i made some tests to simulate hashs 
with integer keys in R2. I used a bitset as an index, mixed with 
block of blocks to store data.

my tests show that for 10000 records,  finding data is near as fast 
as with hashs. 
actually it's incomplete but you have the idea with this:

REBOL []
f: fast-dic: context [
	size: 100000

 hash: 128 - 1	;** hash size speed up the search, must be a power 
 of 2 - 1 (ie. 15, 31, 63, 127, 257 ...)
	master: copy/deep head insert/dup/only [] [] hash + 1
	index: make bitset! size
	flag: func [idx [integer!]][
		unless find index idx [
			insert index idx

   insert/only insert tail pick master idx and hash + 1 idx copy []
		]
	]
	flag?: func [idx [integer!]][find index idx]
	deflag: func [idx [integer!]][
		remove/part index idx
		remove/part find pick master idx and hash + 1 idx 2
	]
] 

t: now/time/precise
loop 10000 bind [flag random 99999] f
print now/time/precise - t
t: now/time/precise
loop 10000 bind [flag? random 99999] f
print now/time/precise - t

The trick with FIND-ALL is that it doesn't reeturn anything - it 
executes a code block wioth each find.

load: func [
	{Loads a file, URL, or string.}

 source [file! url! string! binary! block!] {Source or block of sources}

 /header  {Includes REBOL header object if present. Preempts /all.}

 /next    {Load the next value only. Return block with value and new 
 position.}

;	/library {Force file to be a dynamic library. (Command version)}
;	/markup  {Convert HTML and XML to a block of tags and strings.}
	/all     {Load all values. Does not evaluate REBOL header.}
	/unbound {Do not bind the block.}
	/local data content val rst tmp

][  ; Note: Avoid use of ALL and NEXT funcs, because of /all and 
/next options
	content: val: rst: tmp: none ; In case people call LOAD/local
	
	; Retrieve the script data
	data: case [
		block? source [ ; Load all in block
			return map x source [apply :load [:x header next all unbound]]
		]
		string? source [source] ; Will convert to binary! later
		binary? source [source]
		; Otherwise source is file or url
		'else [
			; See if a codec exists for this file type
			tmp: find find system/catalog/file-types suffix? source word!
			; Get the data, script required if /header
			content: read source  ; Must be a value, not unset
			case [
				binary? :content [content] ; Assumed script or decodable
				string? :content [content] ; Assumed script or decodable
				header [cause-error 'syntax 'no-header source]
				block? :content [content]
				'else [content: reduce [:content]]
			] ; Don't LOAD/header non-script data from urls and files.

  ] ; content is data if content doesn't need copying, or none if it 
  does
	]
	;print [1 "data type?" type? :data 'content true? :content]
	if string? :data [data: to-binary data] ; REBOL script is UTF-8

 assert/type [data [binary! block!] content [binary! string! block! 
 none!]]
	assert [any [binary? :data not header]]
	if tmp [ ; Use a codec if found earlier
		set/any 'data decode first tmp :data

  ; See if we can shortcut return the value, or fake a script if we 
  can't
		case [

   block? :data [if header [insert data val: make system/standard/script 
   []]]

   header [data: reduce [val: make system/standard/script [] :data]]

   (to logic! unbound) and not next [return :data] ; Shortcut return

   any [next any-block? :data any-word? :data] [data: reduce [:data]]
			'else [return :data] ; No binding needed, shortcut return
		]
		assert/type [data block!] ; If we get this far
	]
	;print [2 'data mold to-string :data]
	
	if binary? :data [ ; It's a script
		unless find [0 8] tmp: utf? data [ ; Not UTF-8
			cause-error 'script 'no-decode ajoin ["UTF-" abs tmp]
		]
		; Process the header if necessary
		either any [header not all] [
			if tmp: script? data [data: tmp] ; Load script data
			; Check for a REBOL header
			set/any [val rst] transcode/only data
			unless case [
				:val = [rebol] [ ; Possible script-in-a-block
					set/any [val rst] transcode/next/error rst
					if block? :val [ ; Is script-in-a-block
						data: first transcode/next data
						rst: skip data 2
					] ; If true, val is header spec
				]
				:val = 'rebol [ ; Possible REBOL header
					set/any [val rst] transcode/next/error rst
					block? :val ; If true, val is header spec
				]
			] [ ; No REBOL header, use default
				val: [] rst: data
			]
			; val is the header spec block, rst the position afterwards

   assert/type [val block! rst [binary! block!] data [binary! block!]]
			assert [same? head data head rst]
			; Make the header object

   either val: attempt [construct/with :val system/standard/script] 
   [
				if (select val 'content) = true [
					val/content: any [:content copy source]
				]
			] [cause-error 'syntax 'no-header data]
			; val is correct header object! here, or you don't get here
			; Convert the rest of the data if necessary and not /next
			unless any [next block? data] [data: rst: to block! rst]
			if block? data [ ; Script-in-a-block or not /next
				case [

     header [change/part data val rst] ; Replace the header with the object

     not all [remove/part data rst]	; Remove the header from the data
				]
				rst: none ; Determined later
			]
		] [rst: data] ; /all and not /header
	]

 ; val is the header object or none, rst is the binary position after 
 or none

 assert/type [val [object! none!] rst [binary! none!] data [binary! 
 block!]]

 assert [any [none? rst same? head data head rst] any [val not header]]

 ;print [3 'val mold/all :val 'data mold/all :data "type?" type? :data]
	
	; LOAD/next or convert data to block - block either way
	assert [block? data: case [
		not next [ ; Not /next
			unless any [block? data not binary? rst] [data: to block! rst]
			data
		]
		; Otherwise /next

  block? data [reduce pick [[data] [first+ data data]] empty? data]
		header [reduce [val rst]] ; Already transcoded above
		binary? rst [transcode/next rst]
	]]
	
	; Bind to current global context if not a module
	unless any [ ; Note: NOT ANY instead of ALL because of /all
		unbound
		(select val 'type) = 'module
	][
		bind/new data system/contexts/current
	]
	;print [6 'data mold/all :data 'tmp mold/all :tmp]
	
	; If appropriate and possible, return singular data value
	unless any [
		all header next  ; /all /header /next
		empty? data
		1 < length? data
	][set/any 'data first data]
	;print [7 'data mold/all :data]
	
	:data
]

Steeve .. do you say this to me because of find-each :) .. I mean 
a fing that uses block of code to determine what to find .. like: 
find-each x numbers [ x > 3 ]    ... in same manner as map/fold/filter 
work

I use map reduce and seek  at jsgoo and I can do a lot of stuff with 
those (an appy inject for dictionaries) .. let's say you want to 
check if users with username and password exists in a block of users:

find-each U users [ all [ equal? U/user user equal? U/pwd pwd ] ] 
... much cleaner and more error prone than with foreach IMHO ( and 
these functions show intent of why you are looping through block 
of users )

I think that FIND/all would just return true/false, not a block full 
of positions.

I think he means both. He just talks about TRUE/FALSE for bitsets:


One possible justification would be if FIND/all is useful for other 
series. For example, a FIND/all on a block might return a block of 
results.

hmm... how can i map a directory under a certain path in vhost? im 
trying this:
yp [  root-dir %~/p/ob/yp  alias "/public" %../public/ ]

then for curl http://yp:8080/public/angular-0.9.15.min.js  i get

HTTP/1.1 301 Moved Permanently
Location: /public/angular-0.9.15.min.js/

wtf?

i remember seeing something like "/some/path" [ options ] in a vhost 
config block, but i can't find anything about it now

My first though is to have a map (an image) of countries where each 
country has its own color (call it a color-map) and another map of 
the same size that you display (diplay-map).
Then you have a block of pairs [country-name country-color].
So like this you have a relationship in any sense.


Click the displayed map => find the corresponding pixel in the color-map 
=> find the country name in the block.

To know the edge of the country you want to fill, just find all the 
pixels of this same color in the color-map and poke the corresponding 
pixel on the diplay-map.

intersect is a native so the only way you can get faster performance 
is if you know something about the blocks contents. For example, 
if both blocks contain sorted integers *and* one block is smaller 
than the other *and* the bigger block contains the first value of 
the smaller then the following code *may* be faster than intersect:

	a: [2 3 4]
	b: [1 2 3 4 5]
	x: last b
	b: find b first a
	r: copy []
	foreach i a [
		all [i > x break]
		all [find b i append r i]
	]
	b: first b

Your block scheme probably wouldn't have benefited from asynchronicity 
that much. Or would it have? That would be interesting to find out.

And the programmer that matters when it comes to BIND is the one 
that is calling BIND, and providing the code block. Not the one that 
made the context.

 - this is interesting, again. My note is, that if the context was 
 created to support e.g. the functionality of For, then any subsequent 
 binding is meaningful for me, only if the functionality remains supported. 
 I think this way, even when I am the one calling Bind and providing 
 the block, unfortunately, I may not know, which alternative mentioned 
 by you to use, not knowing the type of the context I obtained.


As opposed to that, when I see a context without 'self, I know, that 
the context was created so, that it is not meant to support 'self 
binding, and that is all I need to know. How would you do it obtaining 
a context of unknown origin, that would contain '"unsolicited" self? 
(of course, not knowing that information, since there is no way how 
you can find that out)

I have a XML file and want to handle it by tags like a nested block. 
Are there are any tricks? Or do I need to use PARSE / FIND etc.

Here's a low-level function to parse and process script headers, 
which shows how many features are built into the base script model 
in R3:

load-script: funct [
	"Decode a script into [header-obj script-ref body-ref]"

 source [binary! string!] "Source code (string will be UTF-8 encoded)"
	/header "Return the header object only, no script processing"

 ;/check "Calculate checksum and assign it to the header checksum 
 field"
	/original "Use original source for Content header if possible"
] compose [
	data: either string? source [to-binary source] [
		unless find [0 8] tmp: utf? source [ ; Not UTF-8
			cause-error 'script 'no-decode ajoin ["UTF-" abs tmp]
		]
		source
	]

 ; Checksum all the data, even that before the header or outside the 
 block
	;sum: if check [checksum/secure data]  ; saved for later
	
	if tmp: script? data [data: tmp] ; Find the start of the script
	
	; Check for a REBOL header
	set/any [hdr: rst:] transcode/only data
	unless case [
		:hdr = 'rebol [ ; Possible REBOL header
			set/any [hdr rst] transcode/next/error rst
			block? :hdr ; If true, hdr is header spec
		]
		:hdr = [rebol] [ ; Possible script-in-a-block
			set/any [hdr rst] transcode/next/error rst
			if block? :hdr [ ; Is script-in-a-block
				unless header [ ; Don't decode the rest if /header
					data: first transcode/next data
					rst: skip data 2
				]
				true
			] ; If true, hdr is header spec
		]
	] [ ; No REBOL header, use default
		hdr: [] rst: data
	]
	; hdr is the header spec block, rst the position afterwards

 ;assert/type [hdr block! data [binary! block!] rst [binary! block!]]
	;assert [same? head data head rst]
	
	; Make the header object, or fail if we can't

 unless hdr: attempt [construct/with :hdr system/standard/header] 
 [
		cause-error 'syntax 'no-header data
	]
	; hdr is a correct header object! here, or you don't get here

 ;if check [append hdr 'checksum  hdr/checksum: sum]  ; calculated 
 earlier

 ;assert [sum =? select hdr 'checksum]  ; Should hdr/checksum be reserved?
	

 if header [return hdr] ; If /header, no further processing necessary

 ; Note: Some fields may not be final because post-processing is not 
 done.
	
	; Skip any whitespace after the header

 ws: (charset [1 - 32]) ; For whitespace skipping (DEL not included)
	if binary? rst [parse rst [any ws rst:]] ; Skip any whitespace
	
	; Check for compressed data and decompress if necessary
	case [
		; Magic autodetection of compressed binary
		tmp: attempt [decompress rst] [
			data: rst: tmp  ; Use decompressed data (no header source)
			append hdr 'compressed  hdr/compressed: true ; Just in case
		]
		; Else not directly compressed (without encoding)
		(select hdr 'compressed) != true [] ; Not declared, do nothing
		; Else it's declared to be compressed, thus should be
		binary? rst [ ; Regular script, check for encoded binary
			set/any [tmp rst] transcode/next/error rst
			either tmp: attempt [decompress :tmp] [
				data: rst: tmp  ; Use the decoded binary (no header source)
				hdr/compressed: 'script  ; So it saves the same way
				; Anything after the first binary! is ignored
			] [cause-error 'script 'bad-press -3] ; Else failure
		]
		; Else it's a block, check for script-encoded compressed binary
		tmp: attempt [decompress first rst] [

   data: rst: tmp  hdr/compressed: 'script  ; It's binary again now
		]
		; Else declared compressed but not compressed, so fail
		'else [cause-error 'script 'bad-press -3]
	]
	
	; Save the script content in the header if specified
	if :hdr/content = true [
		hdr/content: either original [source] [copy source]
	]
	

 ;assert/type [hdr object! data [binary! block!] rst [binary! block!]]
	;assert [same? head data head rst]

 reduce [hdr data rst]  ; Header object, start of source, start of 
 body
]


Note all the commented assert statements: they are for testing (when 
uncommented) and documentation. Also, I later removed the checksum 
calculation from this code because it was the wrong place to put 
it, at least as far as modules are concerned. However, Carl didn't 
know this because he was working on it while I was offline for a 
few days.

Here is the corresponding function in the code reorg, renamed. The 
friendly empty lines and comments haven't been added yet.

load-header: funct/with [
	"Loads script header object and body binary (not loaded)."

 source [binary! string!] "Source code (a string! will get UTF-8 encoded)"

 no-decompress [logic!] "Skip decompression of body (because we want 
 to look at header mainly)"
][
	; This function decodes the script header from the script body.

 ; It checks the 'checksum, 'compress and 'content fields of the header.

 ; It will set the 'content field to the binary source if 'content 
 is true.

 ; It will set the 'compress field to 'script for compressed embedded 
 scripts.

 ; If body is compressed, it will be decompressed (header required).

 ; Normally, returns the header object and the body text (as binary).

 ; If no-decompress is false and the script is embedded and not compressed
	; then the body text will be a decoded block instead of binary.
	; Errors are returned as words:
	;    no-header
	;    bad-header
	;    bad-checksum
	;    bad-compress
	; Note: set/any and :var used - prevent malicious code errors.
	case/all [
		binary? source [data: assert-utf8 source]
		string? source [data: to binary! source]
		not data: script? data [return reduce [none data]] ; no header

  set/any [key: rest:] transcode/only data none ; get 'rebol keyword

  set/any [hdr: rest:] transcode/next/error data none ; get header 
  block

  not block? :hdr [return 'no-header] ; header block is incomplete

  not attempt [hdr: construct/with :hdr system/standard/header][return 
  'bad-header]

  :hdr/content = true [hdr/content: data] ; as of start of header (??correct 
  position??)
		:key = 'rebol [ ; regular script

   rest: any [find rest non-ws rest] ; skip whitespace after header

   ;rest: any [find rest #[bitset! [not bits #{7FFFFFFF80}]] rest] ; 
   skip whitespace
			case/all [

    all [:hdr/checksum :hdr/checksum != checksum/secure rest] [return 
    'bad-checksum]

    no-decompress [return reduce [hdr rest]] ; decompress not done

    :hdr/compress = 'script [set/any 'rest first transcode/next rest]
			] ; rest is now suspect, use :rest
		]

  :key = [rebol] [ ; embedded script, only 'script compression supported
			case/all [
				:hdr/checksum [return 'bad-checksum] ; checksum not supported

    no-decompress [return reduce [hdr rest]] ; decompress not done

    rest: skip first transcode/next data 2 none ; decode embedded script

    :hdr/compress [hdr/compress: unbind 'script  set/any 'rest first 
    rest]
			] ; rest is now suspect, use :rest
		]

  :hdr/compress [rest: attempt [decompress :rest]] ; :rest type-checked 
  by decompress

  not :rest [return 'bad-compress] ; only happens if above decompress 
  failed
	]

 ;assert/type [hdr object! rest [binary! block!]] ; just for documentation
	reduce [hdr rest]
][
	non-ws: charset [not 1 - 32]
]

Notes:

- The other half of the CASE/all style is a lot of explicit shortcut 
RETURN statements, whenever the normal flow differs.

- Errors are returned as a word from the error catalog, which is 
later passed to CAUSE-ERROR.

- Carl redid the checksum calculation so that scripts can verify 
against a checksum in their header, to detect corruption.

- The checksum in the header probably can't be used for the module 
checksum because the header itself matters for modules.

- Compressed scripts lost a couple minor, unimportant features that 
we are likely better without. Quiz: What features?

- Part, but not all of the reason the code is shorter is because 
the doc comments haven't been added yet. The CASE/all style helps 
though.

here my simple but effective r3 search function:

;------------------------------------------------------------
search-body: funct [
	data [object! block! function!] "what to search"
	word [word!] "what to find"
	/paths "only returns paths, not their values"
	/indents i "how many tabs when listing?"
	/into blk "Add matches to this block"
	/path pth [lit-path!] "keep track of path"
][
	
	i: any [i 0]
	
	unless into [
		set 'searched-objects copy [] ; will set in "globals"
	]
	
	either block? :data [
		b: data
	][
		b: body-of :data
	]
	
	
	; locals
	item: none
	match?: false
	blk: any [blk copy []]
	pth: any [all [pth copy pth] to-lit-path ""]
	last-set-word: none
	counter: 0
	
	foreach item :b [
		counter: counter + 1
		
		result: switch/default type?/word :item [
			set-word! [
				last-set-word: :item
				false
			]
			object! [
				; prevent endless cycles on self or inter references.
				unless find searched-objects :item [
					append searched-objects :item
					either block? data [

      search-body/indents/into/path :item word i + 1 blk append copy pth 
      counter
					][

      search-body/indents/into/path :item word i + 1 blk append copy pth 
      to-word last-set-word
					]
				]
				true
			]
			function! [
				either word = to-word last-set-word [
					; adds the definition OF the searched item

     append/only blk to-lit-path append/only copy pth last-set-word
					append/only blk mold :item
				][
					if search-body/indents/into/path :item word i + 1 blk pth [
						; adds a function WITH the searched item in it

      append/only blk to-lit-path append/only copy pth last-set-word
						append/only blk mold :item
					]
				]
				true
			]
			integer! tuple! string! [
				if last-set-word [
					if word = to-word last-set-word [

      append/only blk to-lit-path append/only copy pth last-set-word
						append/only blk  :item
					]
				]
				true
			]
			block! [

    search-body/indents/into/path :item word i + 1 blk append copy pth 
    counter
				true
			]
			
			; this is what we search for
			word! [
				either :item = word [
					match?: true
				][
					false
				]
			]
			
		][
			; these types are not specifically managed by the search
			false
		]
	]
	either into [
		match?
	][
		set 'quiet-search? false
		new-line/skip blk true 2
	]
]
;----------------------------------------------

We can't remove /case. So the new option would not have to be a superset 
of /case, it would be additive. What would you call an option that 
made it consider datatypes? Keep in mind that this option would only 
apply to block types, so would be overhead for other types that implement 
the FIND and SELECT actions.

I guess, that I owe a little more to the readers, so here is an example 
illustrating what I actually mean:

let's define a block as follows:

    a-block: [[1] [2]]


at the present state, it is obvious, that first a-block and second 
a-block are not identical
illustration:

    same? first a-block second a-block ; == false

now, let's use the CHANGE function:

    change/only next a-block first a-block
    a-block ; == [[1] [1]]

due to the way we did it,

and due to reflexivity of identity, first a-block and second a-block 
yield the same value,
after this operation

("the same" in the sense, that there is only one value, which happens 
to be the value both expressions yield.)


since first a-block and second a-block are two expressions yielding 
just one value,
we conclude (as a consequence of that), that the respective value
is not contained in the first slot of the A-BLOCK block

(if it were "contained" in there we could not be able to see, that 
the value is actually not "contained" in there)


Usíng the same approach for any other REBOL value, we can demonstrate, 
that no value is "contained" in "value slot". Since we *can* find 
out "Which value is the first a-block value?" there is only one conclusion 
we can make: using the first a-block expression we can refer to the 
value (this is why I use the words "reference", "refer"), but that 
does not mean, any other "reference" cannot "refer" to that value 
as well, thus the value "is not contained", but just "referenced".

John, you are missing some things others know and find obvious. For 
example, do you know the answer to the following question?

    What is the ratio between

        stringn: func [n] [head insert/dup copy "" #"a" n]


        word: to word! stringn 1 t1: time-block [equal? word word] 0,05

        word: to word! stringn 1000 t2: time-block [equal? word word] 0,05
        t2 / t1

compared to


        string: stringn 1 t1: time-block [equal? string string] 0,05

        string: stringn 1000 t2: time-block [equal? string string] 0,05
        t2 / t1
?

Desiding what to do with block indexes out of range is a tough call, 
I think. I understand the argument not to cause errors, if it can 
be handled somehow, but I'm not sure, handling out-of-range problems 
is always good. What if it's a user bug in the code, that made the 
index get out of range? Then the user won't easily find that bug, 
as it causes no error.


It's not possible to index a block lower than 1 (first element). 
It's only possible to index out of range in the other end of the 
block, getting past the tail. And that can only be done by having 
an index there, and then remove something from earlier in the block. 
When the index is beyond the tail, then it has to be desided what 
to do with
	insert, remove, skip, next, back, pick, select, append
used on that index. (and maybe more like TAIL?, INDEX?, ...)

What does other languages do?