[m-rev.] for post-commit review: clean up code that adds pred and mode decls to HLDS

[Julien Fischer]

On Wed, 19 May 2021, Zoltan Somogyi wrote:

> Simplify adding pred and mode decls to HLDS.

...

> diff --git a/compiler/add_pred.m b/compiler/add_pred.m
> index d6b930e77..cfc2fd5e1 100644
> --- a/compiler/add_pred.m
> +++ b/compiler/add_pred.m
> @@ -116,16 +118,98 @@
>  :- import_module term.
>  :- import_module varset.
> 
> -module_add_pred_decl(PredStatus, NeedQual, ItemPredDecl, MaybePredProcId,
> -        !ModuleInfo, !Specs) :-
> -    ItemPredDecl = item_pred_decl_info(PredSymName, PredOrFunc, TypesAndModes,
> -        WithType, WithInst, MaybeDetism, Origin, TypeVarSet, InstVarSet,
> -        ExistQVars, Purity, Constraints, Context, SeqNum),
> +module_add_pred_decl(ItemMercuryStatus, PredStatus, NeedQual, ItemPredDecl,
> +        MaybePredProcId, !ModuleInfo, !Specs) :-
> +    ItemPredDecl = item_pred_decl_info(PredSymName, PredOrFunc,
> +        ArgTypesAndModes, WithType, WithInst, MaybeDetism,
> +        Origin, TypeVarSet, InstVarSet, ExistQVars, Purity, Constraints,
> +        Context, SeqNum),
>      % Any WithType and WithInst annotations should have been expanded
>      % and the type and/or inst put into TypesAndModes by equiv_type.m.
>      expect(unify(WithType, no), $pred, "WithType != no"),
>      expect(unify(WithInst, no), $pred, "WithInst != no"),
> 
> +    PredName = unqualify_name(PredSymName),
> +    ( if PredName = "" then
> +        Pieces = [words("Error: you cannot declare a"),
> +            words(pred_or_func_to_full_str(PredOrFunc)),
> +            words("whose name is a variable."), nl],
> +        Spec = simplest_spec($pred, severity_error, phase_parse_tree_to_hlds,
> +            Context, Pieces),
> +        !:Specs = [Spec | !.Specs],
> +        MaybePredProcId = no
> +    else
> +        split_types_and_modes(ArgTypesAndModes, ArgTypes, MaybeArgModes0),
> +        list.length(ArgTypes, PredFormArity),
> +        ( if
> +            PredOrFunc = pf_predicate,
> +            MaybeArgModes0 = yes(ArgModes0),
> +            % If a predicate declaration has no arguments ano no determinism,

s/ano/and/

> +            % then it has none of the components of a mode declaration.
> +            ArgModes0 = [],

That's fine otherwise.

Julien.