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a0e5667af5
For review by anyone. Estimated hours taken: 10 Branches: main, release Do not allow non-abstract instance declarations to occur in module interfaces. Emit an error message if this occurs. Fix the formatting of some error messages regarding typeclasses and instances. compiler/check_typeclass.m: Use error_util to generate the error messages from this module. This fixes a problem where the printing of sym_names and arities differed in the same error message. compiler/error_util.m: Add a format component for the pred_or_func type. Add the equivalence type format_components. compiler/make_hlds.m: Make the format of some error messages concerning typeclasses more consistent. compiler/modules.m: Check for non-abstract instance declarations in module interfaces and emit an error message if they do. tests/invalid/Mmakefile: tests/invalid/instance_bug.m: tests/invalid/instance_bug.err_exp: Test case for the above. tests/hard_coded/typeclasses/*: tests/invalid/*: tests/recompilation/*: tests/valid/*: Update test cases as necessary.
33 lines
776 B
Mathematica
33 lines
776 B
Mathematica
:- module instance_superclass.
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% This is a regression test for the case where there is a superclass
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% relationship, and the instance declaration has a type variable in the
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% instance type.
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:- interface.
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:- import_module list.
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:- typeclass c1(T) where [ ].
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:- typeclass c2(T) <= c1(T) where [ ].
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:- instance c1(list(T)).
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:- instance c2(list(T)).
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:- pred p(T::in) is det.
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:- implementation.
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:- instance c1(list(T)) where [].
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:- instance c2(list(T)) where [].
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% The bug that this test case is checking for is at the creation of
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% the typeclass info for this call: if the substitution from "T" in
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% the typeclass decl to "list(T)" in the instance is applied
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% recursively, an infinite loop results.
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p(X) :- q([X]).
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:- pred q(T) <= c2(T).
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:- mode q(in) is det.
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q(_).
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