Can this be done?
[1/3] from: Steven::White::ci::bloomington::mn::us at: 23-Apr-2003 10:01
I see a deficiency in the REBOL documenatation. It is possible to find
out what a given function does, but it is hard to go in reverse, to find
out which function to use to execute a given idea.
I want to write a function that will pop up an alert box with text
based on a message number that is passed to the function. The "alert"
function will take a data name that identifies its text, but it does not
seem to take a data name which identifies the NAME of the text--sort of
like double indirect addressing.
I have enclosed a sample script that shows what I want to do. The key
statement is the "alert" statement. I am wondering if there is some
function that can be applied to MSG-ID so that REBOL will evaluate
MSG-ID to get the name of the message, and then evaluate the name of the
message to get the actual message.
Thank you.
#####################################
This is a test program to find out how to
make an alert box with a variable message.
REBOL [
]
; -- These are the possible message texts that can go
; -- in the alert box. Each is identified by a name
; -- that consists of a literal "MSG-" followed by
; -- a unique three-digit number.
;
MSG-001: "This is message number one"
MSG-002: "This is message number two"
; -- This function displays an alert box with message
; -- text based on a three-digit number passed to the
; -- function. The function uses the three-digit number
; -- to create a name for the message text, and then
; -- uses that name to get the message text.
; -- (At least, that is the plan, since this does not
; -- work.)
SHOWALERT: func [
;
; -- description of the function and its parameters --
;
"Display alert box with message based on passed message number"
MSG-NUMBER [string!] "Message number as three-byte string"
][
;
; -- the "code" for the function --
;
; -- Generate the word whose value is the NAME of the desired text
;
MSG-ID: append "MSG-" MSG-NUMBER
;
; -- Pop up an alert box containing the desired text.
; -- MSG-ID will evaluate to MSG-nnn where nnn is the message
; -- number. We would like the value of MSG-ID to be evaluated
; -- AGAIN to obtain the text that is the value of the word
; -- that is the value of MSG-ID--a bit of double indirect
; -- addressing.
;
alert [ MSG-ID "CLEAR" ]
]
SHOWALERT "001"
print "Returned from SHOWALERT function"
;###### end of sample script ##############
Steven White
City of Bloomington
2215 W Old Shakopee Rd
Bloomington MN 55431-3096
USA
952-563-4882 (voice)
952-563-4672 (fax)
[swhite--ci--bloomington--mn--us]
[2/3] from: antonr:iinet:au at: 24-Apr-2003 3:05
Try this out:
>> get MSG-ID: to-word append "MSG-" "002"
== "This is message number two"
then
alert [ get MSG-ID "CLEAR" ]
You will need to do your own zero padding.
But why not convert the id string to an integer?
Can't you put all messages in a block?:
id: to-integer "002"
msg: [
"message one"
"message two"
]
alert reduce [pick msg id "clear"]
or maybe
>> msg: [001 "message one" 002 "message two"]
== [1 "message one" 2 "message two"]
>> select msg to-integer "002"
== "message two"
Anton Rolls.
[3/3] from: greggirwin:mindspring at: 23-Apr-2003 11:34
Hi Steven,
You're close! I stripped out the comments for brevity. You need to
turn the string into a word so REBOL can find its value, then use GET
to retrieve the value.
MSG-001: "This is message number one"
MSG-002: "This is message number two"
SHOWALERT: func [
"Display alert box with message based on passed message number"
MSG-NUMBER [string!] "Message number as three-byte string"
][
MSG-ID: to word! join "MSG-" MSG-NUMBER
alert reduce [ rejoin [MSG-ID " - " get msg-id] "CLEAR" ]
]
SHOWALERT "001"
-- Gregg