forked from dylan-lang/strings
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strings.dylan
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strings.dylan
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Module: %strings
// TODO: optimization
// TODO: which are sealed?
// TODO: what to do about methods for non byte-strings?
define constant <string-or-char> = type-union(<string>, <character>);
// eXpression IF. (Not that the built-in IF isn't an expression.)
define macro xif
{ xif(?test:expression, ?true:expression, ?false:expression) }
=> { if (?test) ?true else ?false end }
{ xif(?test:expression, ?true:expression) }
=> { if (?test) ?true end }
end;
define sealed generic alphabetic?
(string-or-character :: <string-or-char>, #key) => (alphabetic? :: <boolean>);
define method alphabetic?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
uppercase-code?(code) | lowercase-code?(code)
end;
define method alphabetic?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(alphabetic?, slice(string, start, epos))
end;
define sealed generic alphanumeric?
(string-or-character :: <string-or-char>, #key) => (alphanumeric? :: <boolean>);
define method alphanumeric?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
uppercase-code?(code) | lowercase-code?(code) | decimal-digit?(char)
end;
define method alphanumeric?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(alphanumeric?, slice(string, start, epos))
end;
define sealed generic graphic?
(string-or-character :: <string-or-char>, #key) => (graphic? :: <boolean>);
define method graphic?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
as(<integer>, ' ') <= code & code <= as(<integer>, '~')
end;
define method graphic?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(graphic?, slice(string, start, epos))
end;
define sealed generic printable?
(string-or-character :: <string-or-char>, #key) => (printable? :: <boolean>);
define method printable?
(char :: <character>, #key) => (b :: <boolean>)
graphic?(char) | whitespace?(char)
end;
define method printable?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(printable?, slice(string, start, epos))
end;
define sealed generic control?
(string-or-character :: <string-or-char>, #key) => (control? :: <boolean>);
define method control?
(char :: <character>, #key) => (b :: <boolean>)
~ printable?(char)
end;
define method control?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(control?, slice(string, start, epos))
end;
define sealed generic whitespace?
(string-or-character :: <string-or-char>, #key) => (whitespace? :: <boolean>);
define method whitespace?
(char :: <character>, #key) => (b :: <boolean>)
select (char)
// Space, tab, newline, formfeed, carriage return
' ', '\t', '\n', '\f', '\r' => #t;
otherwise => #f;
end select
end;
define method whitespace?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(whitespace?, slice(string, start, epos))
end;
define sealed generic uppercase?
(string-or-character :: <string-or-char>, #key) => (uppercase? :: <boolean>);
define method uppercase?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
uppercase-code?(code)
end;
define method uppercase?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(uppercase?, slice(string, start, epos))
end;
define sealed generic lowercase?
(string-or-character :: <string-or-char>, #key) => (lowercase? :: <boolean>);
define method lowercase?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
lowercase-code?(code)
end;
define method lowercase?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(lowercase?, slice(string, start, epos))
end;
define sealed generic octal-digit?
(string-or-character :: <string-or-char>, #key) => (octal? :: <boolean>);
define method octal-digit?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
as(<integer>, '0') <= code & code <= as(<integer>, '7')
end;
define method octal-digit?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(octal-digit?, slice(string, start, epos))
end;
define sealed generic decimal-digit?
(string-or-character :: <string-or-char>, #key) => (decimal? :: <boolean>);
define method decimal-digit?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
as(<integer>, '0') <= code & code <= as(<integer>, '9')
end;
define method decimal-digit?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(decimal-digit?, slice(string, start, epos))
end;
define sealed generic hexadecimal-digit?
(string-or-character :: <string-or-char>, #key) => (hexadecimal? :: <boolean>);
define method hexadecimal-digit?
(char :: <character>, #key) => (b :: <boolean>)
let code = as(<integer>, char);
as(<integer>, '0') <= code & code <= as(<integer>, '9')
end;
define method hexadecimal-digit?
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (b :: <boolean>)
every?(hexadecimal-digit?, slice(string, start, epos))
end;
define sealed generic char-equal-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
define method char-equal-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
lowercase(char1) = lowercase(char2)
end;
define sealed generic char-less-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
define method char-less-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
lowercase(char1) < lowercase(char2)
end;
define sealed generic char-greater-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
define method char-greater-ic?
(char1 :: <character>, char2 :: <character>) => (eq? :: <boolean>);
lowercase(char1) > lowercase(char2)
end;
define sealed generic string-compare
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2, ignore-case?)
=> (result :: one-of(-1, 0, 1));
define method string-compare
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>),
ignore-case? :: <boolean>)
=> (result :: one-of(-1, 0, 1))
%string-compare(string1, string2, start1, end1, start2, end2, ignore-case?)
end;
define sealed generic string-equal?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (equal? :: <boolean>);
define method string-equal?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0,
end1 :: false-or(<integer>),
start2 :: <integer> = 0,
end2 :: false-or(<integer>))
=> (equal? :: <boolean>)
let ignore-case? = #f;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = 0
end method string-equal?;
define sealed generic string-less?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (less? :: <boolean>);
define method string-less?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>))
=> (less? :: <boolean>)
let ignore-case? = #f;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = -1
end method string-less?;
define sealed generic string-greater?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (greater? :: <boolean>);
define method string-greater?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>))
=> (greater? :: <boolean>)
let ignore-case? = #f;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = 1
end method string-greater?;
define sealed generic string-equal-ic?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (equal? :: <boolean>);
define method string-equal-ic?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>))
=> (equal? :: <boolean>)
let ignore-case? = #t;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = 0
end method string-equal-ic?;
define sealed generic string-less-ic?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (less? :: <boolean>);
define method string-less-ic?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>))
=> (less? :: <boolean>)
let ignore-case? = #t;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = -1
end method string-less-ic?;
define sealed generic string-greater-ic?
(string1 :: <string>, string2 :: <string>, #key start1, end1, start2, end2)
=> (greater? :: <boolean>);
define method string-greater-ic?
(string1 :: <string>, string2 :: <string>,
#key start1 :: <integer> = 0, end1 :: false-or(<integer>),
start2 :: <integer> = 0, end2 :: false-or(<integer>))
=> (greater? :: <boolean>)
let ignore-case? = #t;
%string-compare(string1, string2,
start1, end1 | string1.size,
start2, end2 | string2.size, ignore-case?) = 1
end method string-greater-ic?;
define sealed generic lowercase
(string-or-char :: <string-or-char>, #key)
=> (new-string-or-char :: <string-or-char>);
define method lowercase
(char :: <character>, #key) => (new-char :: <character>)
as-lowercase(char)
end;
define method lowercase
(string :: <string>, #key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (new-string :: <string>)
let epos :: <integer> = epos | string.size;
lowercase!(copy-sequence(string, start: start, end: epos))
end method lowercase;
define sealed generic lowercase!
(string-or-char :: <string-or-char>, #key)
=> (string-or-char :: <string-or-char>);
define method lowercase!
(char :: <character>, #key) => (new-char :: <character>)
as-lowercase(char)
end;
define method lowercase!
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (string :: <string>)
let epos :: <integer> = epos | string.size;
range-check(string, string.size, start, epos);
for (i from start below epos)
string[i] := lowercase(string[i])
end;
string
end method lowercase!;
define sealed generic uppercase
(string-or-char :: <string-or-char>, #key)
=> (new-string-or-char :: <string-or-char>);
define method uppercase
(char :: <character>, #key) => (new-char :: <character>)
as-uppercase(char)
end;
define method uppercase
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (new-string :: <string>)
let epos :: <integer> = epos | string.size;
uppercase!(copy-sequence(string, start: start, end: epos))
end method uppercase;
define sealed generic uppercase!
(string-or-char :: <string-or-char>, #key)
=> (string-or-char :: <string-or-char>);
define method uppercase!
(char :: <character>, #key) => (new-char :: <character>)
as-uppercase(char)
end;
define method uppercase!
(string :: <string>,
#key start :: <integer> = 0, end: epos :: false-or(<integer>))
=> (string :: <string>)
let epos :: <integer> = epos | string.size;
range-check(string, string.size, start, epos);
for (i from start below epos)
string[i] := uppercase(string[i])
end;
string
end method uppercase!;
define sealed generic pad
(string :: <string>, width :: <integer>, #key fill, start, end: epos)
=> (new-string :: <string>);
define method pad
(string :: <string>, width :: <integer>,
#key fill :: <character> = ' ',
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
// Always return a new string, even if no padding is done.
let slen = string.size;
let nlen = max(width, slen);
let spos = floor/(width - slen, 2); // start of "string" in "new"
let new = make(<string>, size: nlen);
for (i :: <integer> from 0 below spos)
new[i] := fill;
end;
for (si :: <integer> from 0 below slen,
ni :: <integer> from spos below spos + slen)
new[ni] := string[si];
end;
for (i :: <integer> from spos + slen below nlen)
new[i] := fill;
end;
new
end method pad;
define sealed generic pad-right
(string :: <string>, width :: <integer>, #key fill, start, end: epos)
=> (new-string :: <string>);
define method pad-right
(string :: <string>, width :: <integer>,
#key fill :: <character> = ' ',
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
// Always return a new string, even if no padding is done.
let slen = string.size;
let nlen = max(width, slen);
let spos = width - slen; // start of "string" in "new"
let new = make(<string>, size: nlen);
for (ni :: <integer> from 0 below spos)
new[ni] := fill;
end;
for (si :: <integer> from 0 below slen,
ni :: <integer> from spos below nlen)
new[ni] := string[si];
end;
new
end method pad-right;
define sealed generic pad-left
(string :: <string>, width :: <integer>, #key fill, start, end: epos)
=> (new-string :: <string>);
define method pad-left
(string :: <string>, width :: <integer>,
#key fill :: <character> = ' ',
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
// Always return a new string, even if no padding is done.
let slen = string.size;
let nlen = max(width, slen);
let new = make(<string>, size: nlen);
for (i :: <integer> from 0 below slen)
new[i] := string[i];
end;
for (i :: <integer> from slen below nlen)
new[i] := fill;
end;
new
end method pad-left;
define sealed generic strip
(string :: <string>, #key test, start, end: epos) => (new-string :: <string>);
define method strip
(string :: <string>,
#key test :: <function> = whitespace?,
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
let untest = complement(test);
let epos :: <integer> = epos | string.size;
let left = %find-key(string, untest, start, epos);
if (~ left)
strip-right(string, test: test, start: start, end: epos)
else
let right = %find-key-from-end(string, untest, start, epos) | epos;
copy-sequence(string, start: left, end: right)
end if
end method strip;
define sealed generic strip-left
(string :: <string>, #key test, start, end: epos) => (new-string :: <string>);
define method strip-left
(string :: <string>,
#key test :: <function> = whitespace?,
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
let epos :: <integer> = epos | string.size;
copy-sequence(string,
start: %find-key(string, complement(test), start, epos) | epos,
end: epos)
end;
define sealed generic strip-right
(string :: <string>, #key test, start, end: epos) => (new-string :: <string>);
define method strip-right
(string :: <string>,
#key test :: <function> = whitespace?,
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (new-string :: <string>)
let epos :: <integer> = epos | string.size;
copy-sequence(string,
start: start,
end: %find-key-from-end(string, complement(test), start, epos)
| string.size)
end;
define sealed generic starts-with?
(string :: <string>, pattern :: <string>, #key ignore-case?, start, end: epos)
=> (starts-with? :: <boolean>);
define method starts-with?
(string :: <string>, pattern :: <string>,
#key ignore-case?,
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (starts-with? :: <boolean>)
let plen :: <integer> = pattern.size;
let epos :: <integer> = epos | string.size;
if (plen <= epos - start)
%string-compare(string, pattern, start, start + plen, 0, plen, ignore-case?) = 0
end
end method starts-with?;
define sealed generic ends-with?
(string :: <string>, pattern :: <string>, #key ignore-case?, start, end: epos)
=> (ends-with? :: <boolean>);
define method ends-with?
(string :: <string>, pattern :: <string>,
#key ignore-case?,
start :: <integer> = 0,
end: epos :: false-or(<integer>))
=> (ends-with? :: <boolean>)
let slen :: <integer> = string.size;
let plen :: <integer> = pattern.size;
let epos :: <integer> = epos | string.size;
if (plen <= epos - start)
%string-compare(string, pattern, epos - plen, epos, 0, plen, ignore-case?) = 0
end
end method ends-with?;
// I decided that slice shouldn't be included in the new strings
// library because it complicates the DEP too much. At some point it
// may be worth writing a separate DEP to include slice in
// common-dylan. There are some interesting and complicated issues.
// I think it could be worth it, but it's not a huge win so not
// urgent. --cgay
define function slice
(string :: <string>, start :: <integer>, _end :: false-or(<integer>))
=> (new-string :: <string>)
let len :: <integer> = string.size;
let _end :: <integer> = _end | len;
// Negative indexes are relative to the end of the string.
if (_end < 0)
_end := len + _end;
end;
if (start < 0)
start := len + start;
end;
range-check(string, string.size, start, _end);
copy-sequence(string, start: start, end: _end)
end function slice;
define generic split-lines
(string :: <string>, #key remove-if-empty?) => (lines :: <sequence>);
define sealed method split-lines
(string :: <string>, #key remove-if-empty? :: <boolean>) => (lines :: <sequence>)
let epos :: <integer> = string.size;
reverse!(iterate loop (bpos :: <integer> = 0, parts :: <list> = #())
let (sep-start, sep-end)
= iterate find-eol (i = bpos) // Recognize CR alone, CRLF, or LF alone.
if (i < epos)
select (string[i])
'\r' =>
let i2 = i + 1;
let char2 = (i2 < epos) & string[i2];
values(i, (char2 = '\n' & i + 2) | i2);
'\n' =>
values(i, i + 1);
otherwise =>
find-eol(i + 1);
end select
end if
end iterate;
let part = copy-sequence(string, start: bpos, end: sep-start | epos);
case
~sep-start =>
xif(remove-if-empty? & empty?(part),
parts,
pair(part, parts));
sep-end = epos => // trailing EOL
pair(part, parts);
remove-if-empty? & empty?(part) =>
loop(sep-end, parts);
otherwise =>
loop(sep-end, pair(part, parts));
end
end)
end method split-lines;
/// Utilities
define inline function uppercase-code?
(code :: <integer>) => (true? :: <boolean>)
as(<integer>, 'A') <= code & code <= as(<integer>, 'Z')
end;
define inline function lowercase-code?
(code :: <integer>) => (true? :: <boolean>)
as(<integer>, 'a') <= code & code <= as(<integer>, 'z')
end;
define inline function %string-compare
(string1 :: <string>, string2 :: <string>,
start1 :: <integer>, end1 :: <integer>,
start2 :: <integer>, end2 :: <integer>,
ignore-case? :: <boolean>)
=> (result :: one-of(-1, 0, 1))
range-check(string1, string1.size, start1, end1);
range-check(string2, string2.size, start2, end2);
let eq? :: <function> = xif(ignore-case?,
method (c1 :: <character>, c2 :: <character>)
as-lowercase(c1) == as-lowercase(c2)
end,
\==);
let less? :: <function> = xif(ignore-case?,
method (c1 :: <character>, c2 :: <character>)
as-lowercase(c1) < as-lowercase(c2)
end,
\<);
iterate loop (i1 :: <integer> = start1, i2 :: <integer> = start2)
case
i1 = end1 =>
xif(i2 = end2, 0, -1);
i2 = end2 =>
1;
otherwise =>
let c1 = string1[i1];
let c2 = string2[i2];
case
eq?(c1, c2) => loop(i1 + 1, i2 + 1);
less?(c1, c2) => -1;
otherwise => 1;
end;
end case
end iterate
end function %string-compare;
define inline function range-check
(sequence :: <sequence>, _size :: <integer>, _start :: <integer>, _end :: <integer>) => ()
when (_start < 0 | _start > _size)
element-range-error(sequence, _start)
end;
when (_end < 0 | _end > _size)
element-range-error(sequence, _end)
end
end;
define inline function %find-key-from-end
(string :: <string>, test :: <function>, start :: <integer>, epos :: <integer>)
=> (key :: false-or(<integer>))
iterate loop (i = epos - 1)
if (i >= start)
xif (test(string[i]),
i + 1,
loop(i - 1))
end
end iterate
end function %find-key-from-end;
// Like find-key but accepts start/end args. Would like to add them to find-key.
define function %find-key
(seq :: <sequence>, test :: <function>, start :: <integer>, epos :: <integer>)
=> (key :: false-or(<integer>))
iterate loop (i = start)
if (i < epos)
xif(test(seq[i]),
i,
loop(i + 1))
end
end
end function %find-key;