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Estimated hours taken: 1 Branches: main extras/moose/moose.m: Fix a bug introduced by petr's last change: put back the `:- import_module list.' declaration, since it is needed for the references to `[]', `[|]', `list', and `list_skel'. But put it back in the implementation section rather than in the interface section, because it is not needed by the interface. extras/moose/tests/Mmakefile: extras/moose/tests/array_based.moo: Add a regression test.
82 lines
1.6 KiB
Plaintext
82 lines
1.6 KiB
Plaintext
% This is a regression test. It tests that Moo supports parsers that do not
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% use lists.
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:- module array_based.
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:- interface.
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:- import_module char, int, array.
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:- type token
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---> ('+')
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; num(int)
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; ('(')
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; (')')
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; eof
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.
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:- parse(exprn/1, token, eof, xx, in, out).
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:- pred scan(array(char), array(token)).
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:- mode scan(in, out) is det.
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:- implementation.
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:- import_module string, require.
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:- rule exprn(int).
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exprn(Num) ---> exprn(A), [+], term(B), { Num = A + B }.
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exprn(Term) ---> term(Term).
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:- rule term(int).
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term(Num) ---> factor(Num).
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:- rule factor(int).
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factor(Num) ---> ['('], exprn(Num), [')'].
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factor(Num) ---> [num(Num)].
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scan(Chars, Toks) :-
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scan(Chars, array__make_empty_array, Toks0),
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Toks = array_reverse(Toks0).
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:- pred scan(array(char), array(token), array(token)).
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:- mode scan(in, in, out) is det.
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scan(Cs0, Toks0, Toks) :-
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( array__size(Cs0) = 0 ->
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Toks = array_cons(eof, Toks0)
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;
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C = Cs0^elem(0),
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Cs = array_tail(Cs0),
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(if
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char__is_whitespace(C)
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then
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scan(Cs, Toks0, Toks)
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else if
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char__digit_to_int(C, Num)
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then
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scan(Cs, array_cons(num(Num), Toks0), Toks)
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else if
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C = ('+')
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then
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scan(Cs, array_cons('+', Toks0), Toks)
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else if
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C = ('(')
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then
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scan(Cs, array_cons('(', Toks0), Toks)
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else if
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C = (')')
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then
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scan(Cs, array_cons(')', Toks0), Toks)
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else
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error("expr: syntax error in input")
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)
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).
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:- func array_cons(T, array(T)) = array(T).
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:- external(array_cons/2).
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:- func array_reverse(array(T)) = array(T).
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:- external(array_reverse/1).
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:- func array_tail(array(T)) = array(T).
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:- external(array_tail/1).
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