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configure.ac: browser/*.m: compiler/*.m: deep_profiler/*.m: library/*.m: ssdb/*.m: runtime/mercury_conf.h.in: runtime/*.[ch]: scripts/Mmake.vars.in: trace/*.[ch]: util/*.c: Fix spelling and doubled-up words. Delete trailing whitespace. Convert tabs into spaces (where appropriate).
50 lines
1.7 KiB
Mathematica
50 lines
1.7 KiB
Mathematica
%---------------------------------------------------------------------------%
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% vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
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%---------------------------------------------------------------------------%
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% Copyright (C) 2000, 2005-2006 The 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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%
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% File: enum.m.
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% Author: stayl.
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% Stability: medium
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%
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% This module provides the typeclass `enum', which describes types
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% which can be converted to and from integers without loss of information.
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%
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%---------------------------------------------------------------------------%
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%---------------------------------------------------------------------------%
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:- module enum.
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:- interface.
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% For all instances the following must hold:
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% all [X] (X = from_int(to_int(X)))
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% all [Int] (some [Y] Int = to_int(Y) => from_int(Int) = Y)
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:- typeclass enum(T) where [
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func to_int(T) = int,
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func from_int(int) = T is semidet
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].
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% `det_from_int(I)' returns the result of `from_int(I)', but throws an
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% exception if `from_int' fails.
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%
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:- func det_from_int(int) = T <= enum(T).
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%---------------------------------------------------------------------------%
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%---------------------------------------------------------------------------%
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:- implementation.
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:- import_module require.
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det_from_int(I) = X :-
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( if X0 = from_int(I) then
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X = X0
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else
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unexpected($module, $pred, "from_int failed")
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).
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%---------------------------------------------------------------------------%
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