Commit Graph

1 Commits

Author SHA1 Message Date
Zoltan Somogyi
0f75764e41 Pinpoint more actual/expected type differences.
compiler/typecheck_errors.m:
    When there is a difference between actual and expected types
    in predicate calls, do not just print the actual and expected types,
    but if possible, point out the specific part(s) that cause the difference.
    For example, report differences in arities, purity, determinism etc.
    Also point out cases where the code is trying to specify the value
    of an existentially quantified type variable.

    When higher order types are printed as part of an error message,
    strip any builtin qualifiers not just from the names of types,
    but also from the names of the argument modes.

    Start each part of an actual/expected pair at the same level of
    indentation.

compiler/error_util.m:
    Add a way to print out small integers as english names (one, two etc)
    instead as numerals (1, 2 etc).

    Add a way to print out purity descriptions.

    Add a component, treat_next_as_first, that specifies that the next
    format_component should be treated as the first part of a sentence
    with respect to (de)capitalization by lower_next_if_not_first,
    even if it is preceded by other format_components in a message.
    This is useful in cases where the code that generates part of an
    error message does not know whether that part will end up at the start
    of the sentence, as the

        <preceding sentence, ending in a period>
        treat_next_as_first <context> lower_next_if_not_first, Words ...

    sequence will keep Words capitalized if <context> is empty,
    but will decapitalize it if <context> is not empty.

    Rename {qual,unqual}_pf_sym_name_orig_arity as
    {qual,unqual}_pf_sym_name_pred_form_arity, since this is clearer.

compiler/prog_out.m:
    Apply the same s/orig_arity/pred_form_arity/ rename to some functions.

compiler/module_qual.qual_errors.m:
    Fix an unrelated problem I came across while working on the changes above:
    stray spaces at the ends of words(...) format_components, which screwed up
    some error messages.

    Simplify the description of classes and predicates by using facilities
    in error_util.m that did not yet exist when this code was converted
    to use error_util.m.

compiler/prog_type.m:
    When stripping builtin qualifiers from types, strip them from the
    modes stored in the higher_order inst into of higher order types as well,
    for the same reason: to eliminate clutter in error messages.

    Make the strip_kind_annotation function return a value that
    shows in its type that the result will *not* be a kinded_type.
    THIS IS THE FIRST USE OF SUBTYPES IN THE COMPILER.

compiler/type_assign.m:
    Fix a long-standing documentation problem.

    The type_assign type has long had a field named ta_external_type_params,
    whose type was external_type_params, which was defined as equivalent
    to a list of type variables. The name does not say what kinds of type
    variables it contains, but the only two places that add type vars to
    this field add type vars that are existentially quantified, either
    by a predicate, or a cons_id. This diff therefore renames this field
    to ta_existq_tvars, and changes its type to be just plain list(tvar).
    (The external_type_params type has no documentation, so it may be used
    to store different kinds of type variables in different places,
    some of which may *not* be existentially quantified. Using the same name
    for different purposes may be confusing.)

compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/check_promise.m:
compiler/check_typeclass.m:
compiler/convert_parse_tree.m:
compiler/hhf.m:
compiler/hlds_desc.m:
compiler/hlds_out_util.m:
compiler/make_hlds_error.m:
compiler/make_hlds_warn.m:
compiler/mark_tail_calls.m:
compiler/module_qual.qualify_items.m:
compiler/post_typecheck.m:
compiler/pred_table.m:
compiler/typecheck.m:
compiler/typecheck_debug.m:
compiler/typeclasses.m:
    Conform to the changes above.

tests/invalid/fbnf.{m,err_exp}:
    The motivating test case for this diff, slightly modified
    from the code posted to m-users.

tests/invalid/type_diff.{m,err_exp}:
    A test case to test the parts of the new code in typecheck_errors.m
    that are not covered by other tests.

tests/invalid/Mmakefile:
    Enable the new test cases.

tests/invalid/ext_type_bug.{m,err_exp}:
    Extend this test case to test the pinpointing of errors that try to bind
    existentially quantified type variables, at both the top level
    and nested inside other type constructors.

tests/invalid/bug197.err_exp:
tests/invalid/higher_order_mode_mismatch.err_exp:
tests/invalid_purity/impure_pred_t1_fixed.err_exp:
tests/invalid_purity/impure_pred_t2.err_exp:
tests/invalid_purity/purity_nonsense.err_exp:
tests/invalid_purity/purity_nonsense2.err_exp:
    Expect pinpointed type differences in these error messages.

tests/invalid/abstract_eqv.err_exp:
tests/invalid/integral_constant_no_suffix.err_exp:
tests/invalid/method_impl.err_exp:
tests/invalid/mixed_up_streams.err_exp:
tests/invalid/try_bad_params.err_exp:
tests/invalid/type_error_ambiguous.err_exp:
tests/invalid/types2.err_exp:
tests/invalid_nodepend/errors2.err_exp:
    Expected updated formatting in these error messages.
2022-10-11 22:59:03 +11:00