[REBOL] Re: COLLECTing results
From: brett:codeconscious at: 24-Jul-2003 21:26
Thanks Andrew, Gabriele, Volker and Robert for your responses.
Latest function below.
Andrew wrote:
> Note: compose/deep and: do [(block)]
Sorry Andrew I don't quite understand what you mean. But I have got rid
compose completely now :^)
Gabriele wrote:
> Small note: you should bind your RESULT word to a fresh context
Thanks for the alert. That prompted me to use USE, but then I realised I
would have a potential naming clash. Then I realised I don't need a result
variable or special context at all! Collect has gone very minimalistic :^)
Volker wrote:
> regarding filtering: there is 'remove-each
Thinking that it is faster to not insert than to insert then remove I
modified Collect to include a filter in the most efficient way I knew how.
Then I compared the timing of this function with just using Volker's
suggestion of removing later using Remove-each. The latter was faster. So I
ripped out my filter code again :^)
Robert wrote:
> did you had a look at the C++ STL library?
No, I haven't - I don't use C++. Sounds interesting though.
Collect is using a code generation approach - I wonder where it can lead.
collect: func [
{Collects block evaluations, use as body in For, Repeat, etc.}
block [block!] "Block to evaluate."
/init result "Initialise the result series."
/only "Inserts into result using Only refinement."
] [
result: any [result make block! 100]
reduce [
pick [insert insert/only] not only 'tail result 'do :block
result
]
]
Regards,
Brett.
