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9c96387183
samples/Mmakefile:
Add the beer program to list of targets.
samples/*.m:
Convert (C->T;E) to (if C then T else E).
Delete trailing whitespace.
Use predmode syntax instead of separate pred and mode
declarations.
samples/interpreter.m:
Fix up one predicate that had some clauses that used
DCGs and others that used state variables.
Don't use the name 'IO' for something that isn't the I/O state.
samples/diff/*.m:
samples/c_interface/c_calls_mercury/mercury_main.m:
samples/c_interface/short_example.m:
Delete trailing whitespace.
62 lines
1.4 KiB
Mathematica
62 lines
1.4 KiB
Mathematica
% file: beer.m
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% author:
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% Fergus Henderson <fjh@cs.mu.oz.au> Thursday 9th November 1995
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% Re-written with new syntax standard library calls:
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% Paul Bone <paul@mercurylang.org> 2015-11-20
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%
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% This beer song is more idiomatic Mercury than the original, I feel bad
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% saying that since Fergus is a founder of the language.
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:- module beer.
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:- interface.
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:- import_module io.
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:- pred main(io::di, io::uo) is det.
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:- implementation.
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:- import_module int.
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:- import_module list.
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:- import_module string.
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main(!IO) :-
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beer(99, !IO).
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:- pred beer(int::in, io::di, io::uo) is det.
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beer(N, !IO) :-
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io.write_string(beer_stanza(N), !IO),
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( if N > 0 then
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io.nl(!IO),
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beer(N - 1, !IO)
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else
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true
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).
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:- func beer_stanza(int) = string.
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beer_stanza(N) = Stanza :-
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( if N = 0 then
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Stanza = "Go to the store and buy some more!\n"
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else
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NBottles = bottles_line(N),
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N1Bottles = bottles_line(N - 1),
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Stanza =
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NBottles ++ " on the wall.\n" ++
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NBottles ++ ".\n" ++
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"Take one down, pass it around,\n" ++
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N1Bottles ++ " on the wall.\n"
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).
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:- func bottles_line(int) = string.
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bottles_line(N) =
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( if N = 0 then
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"No more bottles of beer"
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else if N = 1 then
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"1 bottle of beer"
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else
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string.format("%d bottles of beer", [i(N)])
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).
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