/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2010-2013, University of Amsterdam All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(unicode, [ unicode_property/2, % ?Code, ?Property unicode_map/3, % +In, -Out, +Options unicode_nfd/2, % +In, -Out unicode_nfc/2, % +In, -Out unicode_nfkd/2, % +In, -Out unicode_nfkc/2 % +In, -Out ]). :- use_foreign_library(foreign(unicode4pl)). /** Unicode string handling This library is a wrapper around the [[utf8proc][http://www.public-software-group.org/utf8proc]] library, providing information about Unicode code-points and performing operations (mappings) on Unicode atoms. The central predicate is unicode_map/3, mapping a Unicode atom to another Unicode atom using a sequence of operations. The predicates unicode_nfd/2, unicode_nfc/2, unicode_nfkd/2 and unicode_nfkc/2 implement the four standard Unicode normalization forms. Lump handling: == U+0020 <-- all space characters (general category Zs) U+0027 ' <-- left/right single quotation mark U+2018..2019, modifier letter apostrophe U+02BC, modifier letter vertical line U+02C8 U+002D - <-- all dash characters (general category Pd), minus U+2212 U+002F / <-- fraction slash U+2044, division slash U+2215 U+003A : <-- ratio U+2236 U+003C < <-- single left-pointing angle quotation mark U+2039, left-pointing angle bracket U+2329, left angle bracket U+3008 U+003E > <-- single right-pointing angle quotation mark U+203A, right-pointing angle bracket U+232A, right angle bracket U+3009 U+005C \ <-- set minus U+2216 U+005E ^ <-- modifier letter up arrowhead U+02C4, modifier letter circumflex accent U+02C6, caret U+2038, up arrowhead U+2303 U+005F _ <-- all connector characters (general category Pc), modifier letter low macron U+02CD U+0060 ` <-- modifier letter grave accent U+02CB U+007C | <-- divides U+2223 U+007E ~ <-- tilde operator U+223C == @see http://www.public-software-group.org/utf8proc */ system:goal_expansion(unicode_map(In, Out, Options), unicode_map(In, Out, Mask)) :- is_list(Options), unicode_option_mask(Options, Mask). %! unicode_map(+In, -Out, +Options) is det. % % Perform unicode normalization operations. Options is a list % of operations. Defined operations are: % % * stable % Unicode Versioning Stability has to be respected. % * compat % Compatiblity decomposition (i.e. formatting information is lost) % * compose % Return a result with composed characters. % * decompose % Return a result with decomposed characters. % * ignore % Strip "default ignorable characters" % * rejectna % Return an error, if the input contains unassigned code % points. % * nlf2ls % Indicating that NLF-sequences (LF, CRLF, CR, NEL) are % representing a line break, and should be converted to the % unicode character for line separation (LS). % * nlf2ps % Indicating that NLF-sequences are representing a paragraph % break, and should be converted to the unicode character for % paragraph separation (PS). % * nlf2lf % Indicating that the meaning of NLF-sequences is unknown. % * stripcc % Strips and/or convers control characters. % NLF-sequences are transformed into space, except if one of % the NLF2LS/PS/LF options is given. % HorizontalTab (HT) and FormFeed (FF) are treated as a % NLF-sequence in this case. % All other control characters are simply removed. % * casefold % Performs unicode case folding, to be able to do a % case-insensitive string comparison. % * charbound % Inserts 0xFF bytes at the beginning of each sequence which % is representing a single grapheme cluster (see UAX#29). % * lump % (e.g. HYPHEN U+2010 and MINUS U+2212 to ASCII "-"). % (See module header for details.) % If NLF2LF is set, this includes a transformation of % paragraph and line separators to ASCII line-feed (LF). % * stripmark % Strips all character markings % (non-spacing, spacing and enclosing) (i.e. accents) % NOTE: this option works only with =compose= or =decompose=. %! unicode_nfd(+In, -Out) is det. % % Characters are decomposed by canonical equivalence. unicode_nfd(In, Out) :- unicode_map(In, Out, [stable,decompose]). %! unicode_nfc(+In, -Out) is det. % % Characters are decomposed and then recomposed by canonical % equivalence. It is possible for the result to be a different % sequence of characters than the original. % % @see http://en.wikipedia.org/wiki/Unicode_equivalence#Normal_forms unicode_nfc(In, Out) :- unicode_map(In, Out, [stable,compose]). %! unicode_nfkd(+In, -Out) is det. % % Characters are decomposed by compatibility equivalence. unicode_nfkd(In, Out) :- unicode_map(In, Out, [stable,decompose,compat]). %! unicode_nfkc(+In, -Out) is det. % % Characters are decomposed by compatibility equivalence, then % recomposed by canonical equivalence. unicode_nfkc(In, Out) :- unicode_map(In, Out, [stable,compose,compat]). %! unicode_property(?Char, ?Property) is nondet. % % True if Property is defined for Char. Property is a term % Name(Value). Defined property-names are: % % * category(atom) % Unicode code category of Char. This is one of Cc, Cf, Cn, % Co, Cs, Ll, Lm, Lo, Lt, Lu, Mc, Me, Mn, Nd, Nl, No, Pc, Pd, % Pe, Pf, Pi, Po, Ps, Sc, Sk, Sm, So, Zl, Zp, Zs. When % testing, a single letter stands for all its subcategories. % E.g. to test form a letter, you can use % % == % unicode_property(C, category('L')) % == % % * combining_class(integer) % * bidi_class(atom) % * decomp_type(atom) % * decomp_mapping(list(code)) % * bidi_mirrored(bool) % * uppercase_mapping(code) % * lowercase_mapping(code) % * titlecase_mapping(code) % * comb1st_index(code) % * comb2nd_index(code) % * comp_exclusion(bool) % * ignorable(bool) % * control_boundary(bool) % * extend(bool) % * casefold_mapping(list(code)) % % @tbd Complete documentation unicode_property(Code, Property) :- nonvar(Code), nonvar(Property), !, '$unicode_property'(Code, Property). unicode_property(Code, Property) :- nonvar(Code), !, property(Property), '$unicode_property'(Code, Property). unicode_property(Code, Property) :- var(Code), !, between(0, 0x10ffff, Code), property(Property), '$unicode_property'(Code, Property). property(category(_)). property(combining_class(_)). property(bidi_class(_)). property(decomp_type(_)). property(decomp_mapping(_)). property(bidi_mirrored(_)). property(uppercase_mapping(_)). property(lowercase_mapping(_)). property(titlecase_mapping(_)). property(comb1st_index(_)). property(comb2nd_index(_)). property(comp_exclusion(_)). property(ignorable(_)). property(control_boundary(_)). property(extend(_)). property(casefold_mapping(_)).