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Estimated hours taken: 0.25 library/string.nu.nl: Implement string__float_to_f_string in NU-Prolog. (The C implementation version of this predicate was recently added by petdr; it also needs an NU-Prolog implementation.)
77 lines
2.4 KiB
Plaintext
77 lines
2.4 KiB
Plaintext
%---------------------------------------------------------------------------%
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% Copyright (C) 1995 University of Melbourne.
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% This file may only be copied under the terms of the GNU Library General
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% Public License - see the file COPYING.LIB in the Mercury distribution.
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%---------------------------------------------------------------------------%
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% File: string.nu.nl.
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% Main author: fjh.
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%-----------------------------------------------------------------------------%
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% In NU-Prolog, strings are represented as list of ASCII codes.
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% To do this correctly, we really ought to check that the list of
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% ints are all valid character codes (i.e. <= 255), and if not,
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% call error/1. But string__to_int_list is private to string.m
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% anyway, so for efficiency we don't worry about that run-time type check.
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string__to_int_list(S, S).
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%-----------------------------------------------------------------------------%
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string__to_float(String, Float) :-
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tokenize(String, Num, number, ""),
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Float is float(Num).
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string__float_to_string(Float, String) :-
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sformat("~g", [Float], String).
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string__float_to_f_string(Float, String) :-
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sformat("~f", [Float], String).
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%-----------------------------------------------------------------------------%
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string__index(String, Int, Char) :-
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list__index0(String, Int, Code),
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char__to_int(Char, Code).
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%-----------------------------------------------------------------------------%
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string__append(A, B, C) :-
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list__append(A, B, C).
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%-----------------------------------------------------------------------------%
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string__length(String, Length) :-
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list__length(String, Length).
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%-----------------------------------------------------------------------------%
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string__split(String, Count, LeftString, RightString) :-
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(
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Count =< 0
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->
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LeftString = "",
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RightString = String
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;
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string__to_int_list(String, CodesList),
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list__split_list(Count, CodesList, LeftCodes, RightCodes)
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->
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string__to_int_list(LeftString, LeftCodes),
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string__to_int_list(RightString, RightCodes)
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;
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LeftString = String,
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RightString = ""
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).
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%-----------------------------------------------------------------------------%
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string__first_char(String0, Char, String) :-
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string__to_int_list(String0, List0),
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List0 = [CharCode | List],
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string__to_int_list(String, List),
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char__to_int(Char, CharCode).
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%-----------------------------------------------------------------------------%
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