mirror of
https://github.com/Mercury-Language/mercury.git
synced 2026-04-22 21:03:53 +00:00
b372b47380
Estimated hours taken: 0.25 tests/general/parse_list.m: tests/general/semidet_map.m: s/mercury_builtin/builtin/
39 lines
1.0 KiB
Mathematica
39 lines
1.0 KiB
Mathematica
%
|
|
% This module, originally written by Philip Dart,
|
|
% uncovered a (second) bug in the implementation of semidet predicates
|
|
% in Mercury version 0.4.
|
|
%
|
|
|
|
:- module parse_list.
|
|
:- interface.
|
|
:- import_module std_util, list, io.
|
|
|
|
:- pred main(io__state::di, io__state::uo) is det.
|
|
|
|
:- pred meta_parse_list(pred(Y, Y, X), list(X), Y, Y).
|
|
:- mode meta_parse_list(pred(in, out, out) is semidet, out, in, out) is det.
|
|
|
|
:- implementation.
|
|
:- import_module builtin, int, string.
|
|
|
|
main -->
|
|
{P = lambda([I::in, O::out, N::out] is semidet, one_or_two(N, I, O))},
|
|
( {meta_parse_list(P, [X, Y], [2, 1, 3], _)} ->
|
|
{string__int_to_string(X, SX)},
|
|
{string__int_to_string(Y, SY)},
|
|
io__write_strings(["Success: X = ", SX, "; Y = ", SY, ".\n"])
|
|
; io__write_string("Failure.\n")
|
|
).
|
|
|
|
meta_parse_list(P, L, In, Out) :-
|
|
( call(P, In, Out0, E) ->
|
|
L = [E|L1], meta_parse_list(P, L1, Out0, Out)
|
|
; L = [], Out = In
|
|
).
|
|
|
|
:- pred one_or_two(int::out, list(int)::in, list(int)::out) is semidet.
|
|
one_or_two(1) --> [1].
|
|
one_or_two(2) --> [2].
|
|
|
|
|