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49 lines
1.0 KiB
Mathematica
49 lines
1.0 KiB
Mathematica
%---------------------------------------------------------------------------%
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% vim: ts=4 sw=4 et ft=mercury
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%---------------------------------------------------------------------------%
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:- module impure_method_impl.
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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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:- typeclass c(T) where [
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pred m1(T::in, int::out) is det,
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semipure pred m2(T::in, int::out) is det
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].
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:- type foo
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---> foo.
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:- semipure pred foo_m1(foo::in, int::out) is det.
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:- impure pred foo_m2(foo::in, int::out) is det.
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:- implementation.
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:- instance c(foo) where [
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pred(m1/2) is foo_m1,
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pred(m2/2) is foo_m2
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].
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main(!IO).
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:- pragma foreign_decl("C", "extern int foo_counter;").
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:- pragma foreign_code("C", "int foo_counter = 0;").
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:- pragma foreign_proc("C",
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foo_m1(_F::in, Val::out),
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[will_not_call_mercury, promise_semipure],
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"
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Val = foo_counter;
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").
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:- pragma foreign_proc("C",
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foo_m2(_F::in, Val::out),
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[will_not_call_mercury],
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"
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Val = foo_counter++;"
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).
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foo_m1(_, 0).
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foo_m2(_, 0).
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