54ceaa1f37
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@2146 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
35 lines
663 B
Prolog
35 lines
663 B
Prolog
:- module(string_utils,
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[string/1,
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upcase_string/2,
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downcase_string/2,
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string_length/2,
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concat_strings/3
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]).
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:- use_module(library(lists),
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[append/3]).
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string([]).
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string([A|Cs]) :-
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integer(A),
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A > 0, % no EOF allowed
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A < 0x3ffffff, % UNICODE characters, strictly not yet required.
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string(Cs).
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upcase_string([], []).
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upcase_string([C|Cs], [NC|NCs]) :-
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code_type(C,to_lower(NC)),
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upcase_string(Cs, NCs).
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downcase_string([], []).
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downcase_string([C|Cs], [NC|NCs]) :-
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code_type(C,to_upper(NC)),
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downcase_string(Cs, NCs).
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string_length(S, Length) :-
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length(S, Length).
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concat_strings(S1, S2, New) :-
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append(S1, S2, New).
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