/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2013-2018, University of Amsterdam VU University Amsterdam CWI, 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(atom, [ restyle_identifier/3, % +Style, +In, +Out identifier_parts/2, % +Identifier, -Parts join_identifier_parts/3 % +Style, +Parts, -Identifier ]). :- autoload(library(apply),[maplist/2,maplist/3]). :- autoload(library(ctypes),[is_upper/1]). /** Operations on atoms This library provides operations on atoms that are not covered by builtin predicates. The current implementation is just a start, making code developed in _xpce_ and duplicated in various projects reusable. */ /******************************* * RESTYLE IDENTIFIERS * *******************************/ %! restyle_identifier(+Style, +In, -Out) is det. % % Restyle an identifier by extracting the alnum substrings and % joining them together according to Style. % % @arg Style is one of `'OneTwo'`, `oneTwo`, `one_two`, `'One_Two'` or % a term style(CapitaliseFirst, CapitaliseRest, Separator). % @see join_identifier_parts/3. restyle_identifier(Style, In, Out) :- identifier_parts(In, Parts), join_identifier_parts(Style, Parts, Out). %! identifier_parts(+Identifier, -Parts) is det. % % Parts is a list of atoms that make up Identifier. The parts % found are turned into lowercase, unless all its characters are % uppercase. E.g., % % ?- identifier_parts('sourceCodeURI', X). % X = [source, code, 'URI']. identifier_parts(';', [';']) :- !. identifier_parts('|', ['|']) :- !. identifier_parts('!', ['!']) :- !. identifier_parts(',', [',']) :- !. identifier_parts(Name, Parts) :- atom_codes(Name, Codes), ( phrase(identifier_parts(Parts), Codes) -> true ; maplist(is_symbol_code, Codes) -> Parts = [Name] ). is_symbol_code(Code) :- code_type(Code, prolog_symbol). identifier_parts([H|T]) --> identifier_part(H), !, identifier_parts(T). identifier_parts([]) --> []. identifier_part(H) --> string(Codes, Tail), sep(Tail), !, { Codes = [_|_], atom_codes(H0, Codes), ( maplist(is_upper, Codes) -> H = H0 ; downcase_atom(H0, H) ) }. string(T,T) --> []. string([H|T], L) --> [H], string(T, L). sep([]) --> sep_char, !, sep_chars. sep([T]), [N] --> [T,N], { code_type(T, lower), code_type(N, upper) }. sep([],[],[]). sep_char --> [H], { \+ code_type(H, alnum) }. sep_chars --> sep_char, !, sep_chars. sep_chars --> []. %! join_identifier_parts(+Style, +Parts, -Identifier) % % Join parts of an identifier according to Style. Style is one of: % % - 'OneTwo' % - oneTwo % - one_two % - 'One_Two' % Predefined self explanatory style identifiers % - style(+CapitaliseFirst, +CapitaliseRest, +Separator) % This generalises the above styles. CapitaliseFirst defines % whether the first character of the first part must be a % capital, CapitaliseRest defines capitalization of the remaining % identifier parts and Separator is the character to place between % the parts. join_identifier_parts(Style, [First|Parts], Identifier) :- style(Style, CapFirst, CapRest, Sep), capitalise(CapFirst, First, H), maplist(capitalise(CapRest), Parts, T), atomic_list_concat([H|T], Sep, Identifier). %! style(?Style, ?CapitaliseFirst, ?CapitaliseRest, ?Separator) style('OneTwo', true, true, ''). style(oneTwo, false, true, ''). style(one_two, false, false, '_'). style('One_Two', true, true, '_'). style(style(CFirst, CRest, Sep), CFirst, CRest, Sep). capitalise(false, X, X) :- !. capitalise(true, X, Y) :- atom_codes(X, [H0|T]), code_type(H0, to_lower(H)), atom_codes(Y, [H|T]).