Anonymous user
Apply a callback to an array: Difference between revisions
→{{header|Raven}}: Added REBOL example.
(→{{header|Oz}}: Simplified) |
(→{{header|Raven}}: Added REBOL example.) |
||
Line 903:
dup *
list</lang>
=={{header|REBOL}}==
<lang REBOL>REBOL [
Title: "Array Callback"
Date: 2010-01-04
Author: oofoe
URL: http://rosettacode.org/wiki/Apply_a_callback_to_an_Array
]
map: func [
"Apply a function across an array."
f [native! function!] "Function to apply to each element of array."
a [block!] "Array to process."
/local x
][x: copy [] forall a [append x do [f a/1]] x]
square: func [x][x * x]
; Tests:
assert: func [code][print [either do code [" ok"]["FAIL"] mold code]]
print "Simple loop, modify in place:"
assert [[1 100 81] = (a: [1 10 9] forall a [a/1: square a/1] a)]
print [crlf "Functional style with 'map':"]
assert [[4 16 36] = map :square [2 4 6]]
print [crlf "Applying native function with 'map':"]
assert [[2 4 6] = map :square-root [4 16 36]]</lang>
Output:
<pre>Simple loop, modify in place:
ok [[1 100 81] = (a: [1 100 81] forall a [a/1: square a/1] a)]
Functional style with 'map':
ok [[4 16 36] = map :square [2 4 6]]
Applying native function with 'map':
ok [[2 4 6] = map :square-root [4 16 36]]</pre>
=={{header|Ruby}}==
| |||