[REBOL] Test, please ignore
From: volker::nitsch::gmail::com at: 2-Aug-2005 1:24
---------- Forwarded message ----------
From: Volker Nitsch <[volker--nitsch--gmail--com]>
Date: Aug 2, 2005 1:19 AM
Subject: test
To: ich <[volker--nitsch--gmail--com]>
Hi Tim,
On 8/1/05, Tim Johnson <[tim--johnsons-web--com]> wrote:
> * Anton Rolls <[antonr--lexicon--net]> [050801 01:38]:
> >
> > Hi Tim,
> >
> > Your code below seems to be generating code using a macro.
> > It seems extremely unwieldy to me and needs a clever
> > bit of rebol to shrink it to its essence.
> >
> > What are the changing parts (what value and type are they) ?
> >
> > It looks to me like the changing parts are:
> >
> > - widget style
> > - widget feel
> >
> > where the feel is just used to detect different key presses (?)
> >
> > I would love to know the intention of your code so we
> > can refactor it.
>
> <grin> We just did. We refactored it in rebol. Yes. python
> is cumbersome, but it scales well, and some
> customers want it. Even the code below could be
> factored more. FI: dispatch should be a method
> of kblists...
>
> tim
>
Maybe looking at other languages and showing how to do that in rebol is
not to bad for bilinguists. After all rebol can do pretty conventional oops..
And i would learn what
return ' %s %s,' % (name,dispatch[layout['type']])
does! :)
So lets enter a lesson of Dr Rebols tutorial
SQUEEZING CODE LIKE A PYTHON!
Ok, first lets enter the area of rebol-psychology.
Did you know rebol has a first self and a second self?
And when getting older, even got a third? see:
pdp: func[dump][print mold/all do ?? dump]
proof: context[
me: does[pdp[first self]]
metoo: does[pdp[ second self]]
methree: does[pdp[ third self]]
me metoo methree
]
--output:
dump: [first self]
[self me metoo methree]
dump: [second self]
[
#[object! [
me: #[function! [][pdp [first self]]]
metoo: #[function! [][pdp [second self]]]
methree: #[function! [][pdp [third self]]]
]] #[function! [][pdp [first self]]] #[function! [][pdp [second
self]]] #[function! [][pdp [third self]]]]
dump: [third self]
[me: #[function! [][pdp [first self]]] metoo: #[function! [][pdp
[second self]]] methree: #[function! [][pdp [third self]]]]
(Exercise: figure out what these selfs are ;)
> > Anton.
> >
> > > # Example: explicit
> > > def do_sql(name,layout):
> > > dispatch = {
> > > 'radio':kbLists.do_sql_radio(),
> > > 'text':kbLists.do_sql_text(),
> > > 'textarea':kbLists.do_sql_textarea(),
> > > 'decimal':kbLists.do_sql_decimal(),
> > > 'uinteger':kbLists.do_sql_uinteger(),
> > > 'select':kbLists.do_sql_select(),
> > > 'date':kbLists.do_sql_date(),
> > > 'checkbox':kbLists.do_sql_checkbox(),
> > > 'password':kbLists.do_sql_text(),
> > > }
> > > return ' %s %s,' % (name,dispatch[layout['type']])
>
i hope i get it:
pdp: func [dump] [print mold/all do ?? dump]
; python can easily put kbLists.do_sql_radio() in a list.
; rebol likes to buck when getting functions from pathes.
; so i resort to using functions, more ugly, other way shown later.
; i want to stay close to python-code.
do_sql: func [name layout /local dispatch] [
dispatch: reduce [
"radio" get in kb-lists 'do_sql_radio
"text" get in kb-lists 'do_sql_text
; ..
]
reduce [name select dispatch layout/type]
]
kb-lists: context [
do_sql_radio: does [#radio]
do_sql_text: does [#text]
; ..
]
layo: [
type "radio"
; ..
]
pdp [do_sql "name" layo]
; if the dispatchees are always from lb-lists, we can do
do_sql: func [name layout /local dispatch word] [
dispatch: [
"radio" do_sql_radio
"text" do_sql_text
; ..
]
word: select dispatch layout/type
reduce [name get in kb-list word]
]
; and if the words match to the names, like "radio" -> "do_sql_radio"
do_sql: func [name layout /local dispatch word] [
word: to-word join "do_sql_" name
reduce [name get in kb-list word]
]
; i guess python has similar ways to get from a string to a function,
; tell me ;)
> to elaborate: python automagically builds in internal dictionary
> with the declared class members. Among other things, it allows
> testing for validity of keyword values...
> thus the 'for item in keys' test loop.
>
See rebol-psychology above ;)
> > > # Example: using builtin _dict_ in class constructor
> > > def __init__(self, url='', text='', **kw):
> > > self.target = None
> > > self.onClick = None
> > > self.onMouseOver = None
> > > self.onMouseOut = None
> > > self.url = url
> > > self.text = text
> > > # target ... text constitutue self.__dict__ when they are
> > > # preceded by 'self.'
> > > for item in kw.keys():
> > > if self.__dict__.has_key(item):
> > > self.__dict__[item] = kw[item]
> > > else:
> > > raise KeyError, `item`+' not a valid parameter
> > > for this class.'
> >
clazz: context [
; extra 'demo^init to allow super-call, we are pythonizing
init: demo^init: func [kw /url url* /text text*] [
foreach item next first kw ; the "keys", skip 'self
[
either in self item [
self/:item: get in kw item
; if it can be functions, else kw/:item is ok
] [
make error! rejoin [
"KeyError, " item " not a
valid parameter for this class."
]
]
]
self
]
; can be initialized immediate
target: on-click: on-mouse-over: on-mouse-out: none
]
demo: make clazz []
probe demo/init context [on-click: does["click"]]
probe demo/init context [on-magic: does["magic"]]
; in this simple case we would use the inbuild stuff of course:
demo: make clazz [
on-click: does["click"]
]
> --
> Tim Johnson <[tim--johnsons-web--com]>
> http://www.alaska-internet-solutions.com
> --
> To unsubscribe from the list, just send an email to
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>
--
-Volker
Any problem in computer science can be solved with another layer of
indirection. But that usually will create another problem.
David
Wheeler
--
-Volker
Any problem in computer science can be solved with another layer of
indirection. But that usually will create another problem.
David
Wheeler
