How about this?
collector: func [args [block!] init [series!] code [block!]] [
args: union args [/local out emit]
func args compose [
out: copy (reduce [init])
emit: func [val] [
repend out val
]
(code)
out
]
]
"explicit"
double: collector [series] [] [
foreach num series [
emit 2 * num
]
]
probe double [1 2 3 4]
"inline"
probe do collector [] [] [foreach num [1 2 3 4] [emit 2 * num]]
On 5/12/06, Ladislav Mecir <[EMAIL PROTECTED]> wrote:
>
> Gregg Irwin napsal(a):
> > ; Accepts only word! and block! values for args now.
> >
> > ; Uses 'ins as the name for the first value in the function body.
> > ; and its value is set just before the function is made (for
> > ; visual context).
> >
> >
> ; two comment typos corrected
>
> collect: func [
> [throw]
> {Collects values, returning them as a series.}
> 'emit [word!] "Word used to collect values"
> block [block!] "Block to evaluate"
> /into dest [series!] "Where to append results"
> /only "Insert series values as series"
> ] [
> ; Create a new context containing just one word (the EMIT
> ; argument) and set the 'emit word to refer to the new context
> ; word. Note the care taken to suppress possible conflicts and
> ; undesired evaluations.
> emit: reduce [emit]
> emit: first use emit reduce [emit]
> use [dst ins] copy/deep [
> ; copy/deep lets us use just as the fallback value [] here.
> dst: any [:dest []]
> ; make the function used to collect values.
> ins: either only [[insert/only]] [[insert]]
> set emit func [value [any-type!]] compose [
> (ins) tail :dst get/any 'value
> get/any 'value
> ]
> do bind/copy block emit
> head :dst
> ]
> ]
>
> -L
>
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>
>
--=20
-Volker
"Any problem in computer science can be solved with another layer of
indirection. But that usually will create another problem." David
Wheeler
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