print does not return any value,
I had to work around that in encompass... (hence the /silent refinement)
you can build up a function which returns no value:
a: func [data][
; do what you want with data
return unset 'data
]
the above is not really usefull but if you want to free the memory used up by data
(cause each word in a function keeps its value in between each function call), then
this is one way of ensuring it does not hang around.
ladislav and gabrielle might correct me if I'm wrong.
-MAx
---
"You can either be part of the problem or part of the solution, but in the end, being
part of the problem is much more fun."
> -----Original Message-----
> From: Tim Johnson [mailto:[EMAIL PROTECTED]
> Sent: Friday, November 28, 2003 2:38 PM
> To: [EMAIL PROTECTED]
> Cc: [EMAIL PROTECTED]
> Subject: [REBOL] No return Value???
>
>
>
> Hello Rebols:
> I've got a question:
> I've written a function called 'fetch, which has print
> stubs to help follow the flow control.
>
> If you evaluate 'print with 'fetch, no value is
> returned.
>
> Can someone tell me why this is so?
> TIA
> tim
>
> (example and code follows)
> Example:
> >> do %test-fetch.r
> Script: "Untitled" (none)
> >> fetch 'abc
> type = 'word
> val is unset
> returning unset words as default value
> == none
> >> fetch 'print
> type = 'word
> val is set
>
> The code for 'fetch and helper function 'safe-reduce
> follows:
> REBOL[]
> ;
> --------------------------------------------------------------
> -----------------
> make object! [
> default-value: none
> set 'fetch func[ {safe data retrieval. Handles any value}
> val [any-type!]
> /seed {set default value} /deep {If block, reduce}
> /same {If unset return 'val}
> /local tmp][
> either word? val[
> print "type = 'word"
> either value? val[
> print "val is set"
> get val
> ][
> print "val is unset"
> either same[
> print "returning unset
> word as the word"
> val
> ][
> print "returning unset
> words as default value"
> default-value
> ]
> ]
> ][ ; any other type but 'word
> print ["type = " (type? val)]
> either block? val[
> either deep[
> safe-reduce/deep val
> ][
> safe-reduce val
> ]
> ][
> val
> ]
> ]
> ]
> ]
> ;
> --------------------------------------------------------------
> -----------------
> safe-reduce: function[blk[block!] {reduce block, leaving unset values}
> /deep {reduce nested blocks} ][rblk _reduce][
> dummy: func[val /deep][val] ; pass
> ; below a function assignment using the prefix colon
> _reduce: either deep[:safe-reduce][:dummy]
> ; since 'reduce is a native value (compiled into binary)
> ; try it first
> either all[(not deep) (rblk: attempt[reduce blk])][
> print "Used native 'reduce"
> rblk
> ][
> print "Block with unset values, using 'safe-reduce"
> rblk: make block! length? blk
> foreach element blk[
> either word? element[
> either value? element[
> append rblk (get element)
> ][
> append rblk element
> ]
> ][
> either block? element[
> append/only rblk
> _reduce/deep element
> ][
> append rblk element
> ]
> ]
> ]
> rblk
> ]
> ]
> --
> Tim Johnson <[EMAIL PROTECTED]>
> http://www.alaska-internet-solutions.com
> --
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>
>
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