creating fields in a layout
Hi,
I'm wondering what is wrong with the code that I have here. I want 9 fields to appear across the screen but I don't seem to be able to get them out of the block or string that they are in and append them to the layout. Here is the code:
R E B O L []
lo: [ across ]
for i 1 9 1 [
repend lo [ rejoin ["fld" i ": " "field"]]
]
view layout lo
posted by: john 10-May-2014/23:58-7:00
>> repend lo [ to set-word! join "fld" 1 'field ]
== [fld1: field]
posted by: Graham 11-May-2014/0:24:35-7:00
Hi Graham,
Thanks for that. But where can I find that in the documentation?
posted by: John 11-May-2014/0:56:23-7:00
You have to understand what the difference between words and strings is.
Something like
[ field1: ]
is a set-word! in a block. You can start with a word! or a string!
to set-word! 'field1
or
to set-word! "field1"
posted by: Graham 11-May-2014/1:03:02-7:00
This is pretty foundational stuff. If you haven't read a book on programming in Rebol, I suggest you do so and get this (now) free book
http://www.lulu.com/shop/olivier-auverlot-and-peter-william-alfred-wood/rebol-a-programmers-guide/ebook/product-17515075.html
posted by: Graham 11-May-2014/1:05:24-7:00
Thanks for the reference. Now I have expanded the program and would like it to create more rows but now my i variable does not have a value which I suppose is covered in the book. Here is the code. Perhaps you would be so kind as to tell me what the trouble is with the i variable? R E B O L []
lo: [ across space 0 ]
i:0
for j 1 20 1 [
for k 1 9 1 [
i: i + 1 [
repend lo [to set-word! join "fld" i 'field 100]
]
]
repend lo 'return
]
view layout lo
posted by: John 11-May-2014/1:24:57-7:00
[
repend lo [to set-word! join "fld" i 'field 100]
]
is just a block. You're not doing anything with it.
I suspect you want
for k 1 9 1 [
repend lo [to set-word! join "fld" ++ i 'field 100]
]
posted by: Graham 11-May-2014/1:31:31-7:00
Yes that works like a million bucks. Thx
R E B O L []
lo: [ across space 0 ]
i: 0
for j 1 20 1 [
for k 1 9 1 [
i: i + 1
repend lo [to set-word! join "fld" i 'field 100]
]
repend lo 'return
]
view layout lo
posted by: john 11-May-2014/1:38:54-7:00
Hi
If Graham or Nick or anyone could answer this, I hope it will be instructive. When Graham suggested ++ i, instead of i: i + 1 he was assuming a fuction:
++: func ['word] [set word 1 + get word]
Of course, that works but why? I assumed you could write a function as follows:
++ func [num] [num: num + 1] .
That does NOT work over the function suggested by Graham. But why? Thx for any help.
posted by: John 11-May-2014/17:20:43-7:00
'num is a local variable in the function. It doesn't change the value of the word outside that context.
posted by: Nick 11-May-2014/20:47:22-7:00
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