[REBOL] Re: Web site update
From: lmecir:mbox:vol:cz at: 1-Jul-2004 20:53
Gabriele Santilli napsal(a):
>Mine is surely slower because it isn't using the nice trick you
>are using. :-)
>
You have got my permission to use my implementation if you like (there
is one little bug I have to correct). The corrected version should be:
cfunc: func [
{make a closure}
[catch]
spec [block!] {Help string (opt) followed by arg words (and opt
type and string)}
body [block!] {The body block of the closure}
/local spc locals
] [
body: copy/deep body
spc: make block! 1 + length? spec
insert/only spc [throw]
locals: make block! length? spec
parse spec [
any [
set item any-word! (
insert tail locals to word! :item
insert tail spc to get-word! :item
insert/only tail spc [any-type!]
) | skip
]
]
throw-on-error [
build-func spec 'context [
do func only spc only body insert bind locals context
]
]
]
>#do [document {
>GET-ALL takes a block of words (only WORD!s) and returns a block
>with the respective values. For example:
> a: 1
> b: 2
> get-all [a b] ; == [1 2]
>The difference with REDUCE is that GET-ALL does not evaluate (just
>uses GET/ANY).
>}]
>
BTW, I always thought, that reduce [:a] should be interpreted in such a
way, that we could obtain a block containing *any* type value including
unset! and error! type.
>#do [document {
>CLOSURE creates functions with a dynamic context. It can be used just
>like FUNC, except that it creates a new context at each invocation
>of the function.
>}]
>
>closure:
> func [
> "Defines a closure with given spec and body." [catch]
> spec [block!] "Help string (opt) followed by arg words (and opt type and string)"
> body [block!] "The body block of the closure"
>
> /local word words
> ] [
> words: make block! 2 + length? spec
> parse spec [
> any [
> set word [word! | refinement!] (insert tail words to word! word)
> | skip
> ]
> ]
> throw-on-error [
> make function! spec reduce [
> 'localize words 'copy/deep body
> ]
> ]
> ]
>
>Regards,
> Gabriele.
>
I see two exceptions above - 'localize and 'copy cannot be locals of the
function, i.e. they aren't allowed to occur in Spec. You would have to
use some trick or the BUILD-FUNC function to cure this.
-L
