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a653024ab7
If we want to encourage people to read the sample programs
and learn Mercury programming from them, they should not be written
in an obsolete style.
samples/beer.m:
samples/calculator.m:
samples/calculator2.m:
samples/concurrency/midimon/midimon.m:
samples/diff/diff_out.m:
samples/e.m:
samples/eliza.m:
samples/muz/dict.m:
samples/muz/higher_order.m:
samples/muz/muz.m:
samples/muz/typecheck.m:
samples/muz/word.m:
samples/muz/zabstract.m:
samples/muz/zlogic.m:
samples/muz/zparser.m:
samples/muz/ztoken.m:
samples/muz/ztoken_io.m:
samples/muz/ztype.m:
samples/muz/ztype_op.m:
samples/rot13/rot13_concise.m:
samples/rot13/rot13_gustavo.m:
samples/rot13/rot13_juergen.m:
samples/rot13/rot13_ralph.m:
samples/rot13/rot13_verbose.m:
samples/solutions/all_solutions.m:
samples/solutions/n_solutions.m:
samples/solutions/one_solution.m:
samples/solutions/some_solutions.m:
samples/solver_types/eqneq.m:
samples/solver_types/sudoku.m:
samples/solver_types/test_eqneq.m:
Replace uses of __ as module qualifier with dot.
Replace (C->T;E) with (if C then T else E).
Use our usual indentation for if-then-elses and for switches.
Import one module per line. Put those imports into alphabetical order.
Replace many uses of DCGs with state variables, leaving DCGs
mostly just for parsing code.
Use predmode declarations where this helps.
Put predicates in top-down order where relevant.
Use io.format where this helps.
Do not put more than one predicate call on one line.
Put each function symbol in a du type on a separate line.
Put spaces after commas, around the bar in list syntax,
around arithmetic operators, and around minus signs used for pairs.
Replace tab indentation with four-space indentation.
Delete spaces at the ends of lines.
Replace two or more consecutive blank lines with one blank line.
Delete blank lines that do not help structure the code.
There are probably still some examples of old practices remaining;
I do not claim to have fixed them all.
74 lines
1.6 KiB
Mathematica
74 lines
1.6 KiB
Mathematica
% File: rot13_concise.m
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% Main authors: Warwick Harvey <wharvey@cs.monash.edu.au>
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% Fergus Henderson <fjh@cs.mu.oz.au>
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%
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% rot13_concise:
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%
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% Program to read its input, apply the rot13 algorithm, and write it out
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% again.
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%
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% This version is more concise (but less efficient) than its companion,
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% rot13_verbose.
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%
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% Compile with: mmc --make --infer-all
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%
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% Key features:
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% - is independent of character set (e.g. ASCII, EBCDIC)
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% - has proper error handling
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%
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:- module rot13_concise.
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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 char.
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:- import_module int.
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:- import_module string.
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main(!IO) :-
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read_char(Res, !IO),
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(
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Res = ok(Char),
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io.print(rot13(Char), !IO),
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main(!IO)
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;
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Res = eof
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;
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Res = error(ErrorCode),
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error_message(ErrorCode, ErrorMessage),
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io.stderr_stream(StdErr, !IO),
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io.print(StdErr, "rot13: error reading input: ", !IO),
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io.print(StdErr, ErrorMessage, !IO),
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io.nl(StdErr, !IO)
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).
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:- func rot13(char) = char.
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rot13(Char) = rot_n(13, Char).
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:- func rot_n(int, char) = char.
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rot_n(N, Char) = RotChar :-
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char_to_string(Char, CharString),
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( if sub_string_search(alphabet, CharString, Index) then
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NewIndex = (Index + N) mod cycle + cycle * (Index // cycle),
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string.det_index(alphabet, NewIndex, RotChar)
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else
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RotChar = Char
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).
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:- func cycle = int.
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cycle = 26.
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% The length of `alphabet' should be a multiple of `cycle'.
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%
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:- func alphabet = string.
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alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".
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