Allow MAP-EACH to work on any-string!

[Siskin-Bot]

Submitted by: fork

It would be nice if map-each could take a string in and give a string back.

>> map-each ch "abc<def>ghi&jkl" [
    switch/default ch [
        #"<" ["<"]
        #">" [">"]
        #"&" ["&"]
    ] [
        ch
    ]
]
== "abc<def>ghi&"

The concept here would be that it would take in a string, give it to you character-by-character, and then you could produce a character or string to add to what ultimately becomes a string output.

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^{Imported from: CureCode [ Version: r3 master Type: Wish Platform: All Category: Native Reproduce: Always Fixed-in:none ]
Imported from: metaeducation/rebol-issues#2157}

Comments:

Rebolbot commented on Jun 22, 2014:

Submitted by: BrianH

MAP-EACH should work on strings, but shouldn't by default return a string, it should continue to return a block; that would make it more useful for polymorphic code. Making it return a string should be done with an /as option (similar to Oldes/Rebol-issues#724, with errors triggered for incompatible types), or with an /into option (#709); that would also make it more useful for polymorphic code. Why should the type of the input constrain the output type, when we could have controlled conversion? See Oldes/Rebol-issues#2081 for an example of this kind of controlled conversion.

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Rebolbot added the Type.wish on Jan 12, 2016

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Hostilefork commented on Oct 8, 2018:

Ren-C follows the convention of always producing a BLOCK!, while accepting other series types as input. This leans on some of the justifications given for getting rid of the /INTO refinement....accepting the generality of blocks and looking for other means of optimization.

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Hostilefork added the Ren.resolved on Oct 8, 2018

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