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Source for wiki StringSlicesCowan version 6
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cowan
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127.11.51.1
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StringSlicesCowan
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== String slice library ==
This is a library for manipulating textual content based on ''string slices'', which are references to part of a Scheme string, and ''string cursors'', which are pointers into strings. It is not defined whether the string slice type is disjoint from strings, or whether string cursors are a disjoint type at all. String slices are immutable, and it is an error to mutate the underlying string.
In addition, string cursors may or may not be the same as character-based indexes into strings. For example, in an implementation whose internal representation of strings is UTF-8, string cursors may be pointers to individual bytes in the string. However, the operations provided here (with the exception of those in the Compatibility section) are entirely independent of the character repertoire supported by the implementation.
This proposal also contains a useful subset of SRFI 13, which manipulates strings directly with some allowances for shared substrings (which are both then and now provided only on Guile). The string operations of this proposal are defined in terms of the string slice operations. Unlike SRFI 13, it does not provide ''start'' and ''end'' arguments, as their functionality is subsumed by slices. In addition, the low-level procedures are not provided, nor are any mutation operations. Procedures with the same names and functions as SRFI-13 procedures are marked [SRFI 13]; note that they don't necessarily support all of the arguments of the SRFI 13 versions.
Procedures marked [R7RS-small] are available in the small language, and are not exported by implementations of this proposal. They are included only for completeness.
All predicates passed to procedures defined in this proposal may be called in any order and any number of times, except as otherwise noted.
== Issues ==
1. Allow negative indices in constructors?
2. Titlecase doesn't really fit; keep it?
3. Keep functional update?
4. Keep string trees?
5. Keep compatibility routines, possibly in a different package?
== String constructors ==
`(make-string ` ''k'' [ ''char'' ]`)` [R7RS-small]
`(string `''char'' ...`)` [R7RS-small]
`(string-unfold `''stop? mapper successor'' [ ''seed'' ]`)`
`(string-unfold-right `''stop? mapper successor'' [ ''seed'' ]`)`
`(char->string `''char''`)`
== String slice constructors ==
`(string-slice-whole `''string''`)`
`(string-slice `''string start end''`)`
`(string-subslice `''slice start end''`)`
`(string-slice/cursors `''string start-cursor end-cursor''`)`
`(string-subslice/cursors `''string start-cursor end-cursor''`)`
`(string-slice-transform `''proc slice arg'' ...`)`
`(char->string-slice `''char''`)`
== Predicates ==
`(string-slice? `''obj''`)`
`(string? `''obj''`)` [R7RS-small]
`(string-slice-null? `''slice''`)`
`(string-null? `''string''`)` [SRFI 13]
`(string-slice-every `''pred slice''`)`
`(string-every `''pred string''`)` [SRFI 13]
`(string-slice-any `''pred slice''`)`
`(string-any `''pred string''`)` [SRFI 13]
`(string-slice-whole? `''slice''`)`
`(is-char? `''char''`)`
`(in-char-set? `''char-set''`)`
== Selection ==
`(string-slice-ref `''slice k''`)`
`(string-ref `''string k''`)` [R7RS-small]
`(string-slice-take `''slice n''`)`
`(string-take `''string n''`)` [SRFI 13]
`(string-slice-take-right `''slice n''`)`
`(string-take-right `''string n''`)` [SRFI 13]
`(string-slice-drop `''slice n''`)`
`(string-drop `''string n''`)` [SRFI 13]
`(string-slice-drop-right `''slice n''`)`
`(string-drop-right `''string n''`)` [SRFI 13]
`(string-slice-split-at `''slice n''`)`
`(string-split-at `''string n''`)` [SRFI 13]
`(string-slice-replicate `''slice from to''`)`
`(string-replicate `''string from to''`)`
== Padding, trimming, and compressing ==
`(string-slice-pad `''slice len'' [ ''char'' ]`)`
`(string-pad `''string len'' [ ''char'' ]`)` [SRFI 13]
`(string-slice-trim `''slice len'' [ ''char'' ]`)`
`(string-trim `''string len'' [ ''char'' ]`)` [SRFI 13]
`(string-slice-trim-right `''slice len'' [ ''char'' ]`)`
`(string-trim-right `''string len'' [ ''char'' ]`)` [SRFI 13]
`(string-slice-trim-both `''slice len'' [ ''char'' ]`)`
`(string-trim-both `''string len'' [ ''char'' ]`)` [SRFI 13]
`(string-slice-compress `''slice'' [ ''char'' ]`)`
`(string-compress `''string'' [ ''char'' ]`)`
== Prefixes and suffixes ==
`(string-slice-prefix `''slice,,1,,'' ''slice,,2,,''`)`
`(string-prefix `''string,,1,,'' ''string,,2,,''`)`
`(string-slice-suffix `''slice,,1,,'' ''slice,,2,,''`)`
`(string-suffix `''string,,1,,'' ''string,,2,,''`)` [SRFI 13]
`(string-slice-prefix-length `''slice,,1,,'' ''slice,,2,,''`)`
`(string-prefix-length `''string,,1,,'' ''string,,2,,''`)`
`(string-slice-suffix-length `''slice,,1,,'' ''slice,,2,,''`)` [SRFI 13]
`(string-suffix-length `''string,,1,,'' ''string,,2,,''`)`
`(string-slice-prefix? `''slice,,1,,'' ''slice,,2,,''`)`
`(string-prefix? `''string,,1,,'' ''string,,2,,''`)` [SRFI 13]
`(string-slice-suffix? `''slice,,1,, slice,,2,,''`)`
`(string-suffix? `''string,,1,,'' ''string,,2,,''`)` [SRFI 13]
== Searching ==
`(string-slice-count `''proc slice''`)`
`(string-count `''proc string''`)` [SRFI 13]
`(string-slice-take-while `''proc slice''`)`
`(string-take-while `''proc string''`)` [SRFI 13]
`(string-slice-drop-while `''proc slice''`)`
`(string-drop-while `''proc string''`)` [SRFI 13]
`(string-slice-break `''proc slice''`)`
`(string-break `''proc string''`)` [SRFI 13]
`(string-slice-drop `''proc slice''`)`
`(string-drop `''proc string''`)` [SRFI 13]
`(string-slice-contains `''slice,,1,, slice,,2,,''`)`
`(string-contains `''string,,1,, string,,2,,''`)` [SRFI 13]
== The whole string slice or string ==
`(string-slice-length `''slice''`)`
`(string-length `''string''`)` [R7RS-small]
`(string-slice-copy `''slice''`)`
`(string-copy `''string'' [ ''start'' [ ''end'' ] ]`)` [R7RS-small]
`(string-slice-reverse `''slice''`)`
`(string-reverse `''slice''`)` [SRFI 13]
`(string-slice-append `''slice'' ...`)`
`(string-append `''string'' ...`)` [R7RS-small]
`(string-slice-concatenate `''list-of-slices''`)`
`(string-concatenate `''list-of-strings''`)` [SRFI 13]
`(string-slice-concatenate-reverse `''list-of-slices''`)`
`(string-concatenate-reverse `''list-of-strings''`)` [SRFI 13]
== Folding and mapping ==
`(string-slice-map `''proc slice'' ...`)`
`(string-map `''proc string'' ...`)` [R7RS-small]
`(string-slice-for-each `''proc slice'' ...`)`
`(string-for-each `''proc string'' ...`)` [R7RS-small]
`(string-slice-fold `''proc nil slice''`)`
`(string-fold `''proc nil string''`)` [R7RS-small]
`(string-slice-fold-right `''proc nil slice''`)`
`(string-fold-right `''proc nil string''`)` [R7RS-small]
== Parsing ==
`(string-slice-split `''slice [''char'' [ ''limit'' ] ]`)`
`(string-slice-split `''slice [''char'' [ ''limit'' ] ]`)`
== Filtering and partitioning ==
`(string-slice-filter `''proc slice''`)` [SRFI 13]
`(string-filter `''proc string''`)`
`(string-slice-remove `''proc slice''`)`
`(string-remove `''proc string''`)`
`(string-slice-partition `''proc slice''`)`
`(string-partition `''proc string''`)`
== Conversion ==
`(string-slice->list `''slice''`)`
`(string-slice->vector `''slice''`)`
{{{
string->list [R7RS-small]
list->string [R7RS-small]
vector->string [R7RS-small]
string->vector [R7RS-small]
}}}
== String cursors ==
{{{
string-cursor-start
string-cursor-end
string-cursor-ref
string-cursor-next
string-cursor-previous
string-cursor-forward
string-cursor-backward
string-cursor-forward-until
string-cursor-backward-until
string-cursor=?
string-cursor<?
string-cursor>?
string-cursor<=?
string-cursor>=?
string-cursor->index
string-index->cursor
string-cursors->string
string-cursor-difference
}}}
== Functional update ==
{{{
string-slice-set
string-set
string-slice-fill
string-fill
string-slice-replace
string-replace
string-slice-insert
string-insert
string-slice-delete
string-delete
}}}
== String trees ==
{{{
string-tree->string
write-string-tree
}}}
== Compatibility ==
{{{
string-slice-upcase
string-slice-downcase
string-slice-foldcase
string-slice=?
string-slice<?
string-slice>?
string-slice<=?
string-slice>=?
string-slice-ci=?
string-slice-ci<?
string-slice-ci>?
string-slice-ci<=?
string-slice-ci>=?
string-slice-titlecase
string-titlecase [SRFI 13]
}}}
time
2014-11-24 03:00:32
version
6