How do I pick elements from a block using a string in Rebol?
Given this block
fs: [
usr [
local [
bin []
]
share []
]
bin []
]
I could retrieve an item using a path notation like so:
fs/usr/local
How do I do the same when the path is a string?
path: "/usr/local"
find fs path ;does not work!
find fs to-path path ;does not work!
posted by: AnonMouse 26-Feb-2013/12:21:41-8:00
Are you trying to do this?
do "fs/usr/local"
R E B O L []
fs: [
usr [
local [
bin []
]
share []
]
bin []
]
probe fs/usr/local
probe do "fs/usr/local"
probe do join "fs" "/usr/local"
halt
Output:
[
bin []
]
[
bin []
]
posted by: Nick 26-Feb-2013/18:21:13-8:00
And just for fun:
select select fs to-word "usr" to-word "local"
:)
posted by: Nick 26-Feb-2013/18:50:19-8:00
I use "do" for things like:
R E B O L [title: "Calculator"]
view layout [
origin 0 space 0x0 across
style btn btn 50x50 [append f/text face/text show f]
f: field 200x40 font-size 20 return
btn "1" btn "2" btn "3" btn " + " return
btn "4" btn "5" btn "6" btn " - " return
btn "7" btn "8" btn "9" btn " * " return
btn "0" btn "." btn " / " btn "=" [
attempt [f/text: form do f/text show f]
]
]
R E B O L [title: "Math Test"]
random/seed now
question: does [rejoin [random 10 " + " random 20]]
view layout [
f1: field question
text "Answer:"
f2: field [attempt [
alert either (to-integer f2/text) = (to-integer do f1/text)
["Yes!"]["No"]
f1/text: question show f1 focus f2
]]
]
posted by: Nick 26-Feb-2013/18:55:51-8:00
(Any time you want to evaluate or "execute" concatenated strings of code).
posted by: Nick 26-Feb-2013/18:58:33-8:00
You could take the "do" dialect even farther in that last example:
R E B O L [title: "Math Test"]
random/seed now
question: [rejoin [random 10 " + " random 20]]
view layout [
f1: field (do question)
text "Answer:"
f2: field [attempt [
alert either (to-integer f2/text) = (to-integer do f1/text)
["Yes!"]["No"]
f1/text: do question show f1 focus f2
]]
]
posted by: Nick 27-Feb-2013/9:24:28-8:00
That really helps! Thank you Nick!
posted by: AnonMouse 4-Mar-2013/15:27:05-8:00
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