[m-rev.] for review: use enum to identify impl defined literals

[Peter Wang]

On Thu, 01 Apr 2021 14:01:16 +1100 "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> For review by anyone.
> 
> Also, would people object if I made the code that converts int, float
> and string term functors to cons_ids actually check that they have
> no arguments? Catching mistakes such as 8("abc") only during
> typechecking generates not-all-that-helpful error messages
> that complain about 8 not being a function.

I don't see why not, though I don't remember making that mistake before.

> diff --git a/compiler/prog_data.m b/compiler/prog_data.m
> index c63db3e53..3ccc1b524 100644
> --- a/compiler/prog_data.m
> +++ b/compiler/prog_data.m
> @@ -205,6 +202,15 @@
>  :- type lambda_eval_method
>      --->    lambda_normal.
>  
> +:- type impl_defined_const_kind
> +    --->    idc_file        % $file
> +    ;       idc_line        % $line
> +    ;       idc_module      % $module
> +    ;       idc_pred        % $pred
> +    ;       idc_grade.      % grade

$grade in the comment.

> diff --git a/compiler/superhomogeneous.m b/compiler/superhomogeneous.m
> index 2477e995f..c9340e631 100644
> --- a/compiler/superhomogeneous.m
> +++ b/compiler/superhomogeneous.m
...
> +        ( if
> +            ( Name = "line",   IDCKind = idc_line
> +            ; Name = "file",   IDCKind = idc_file
> +            ; Name = "module", IDCKind = idc_module
> +            ; Name = "pred",   IDCKind = idc_pred
> +            ; Name = "grade",  IDCKind = idc_grade
> +            )
> +        then
> +            ConsId = impl_defined_const(IDCKind)
> +        else
> +            ErrorTerm = functor(Functor, ArgTerms, Context),
> +            TermStr = describe_error_term(VarSet, ErrorTerm),
> +            Pieces = [words("Error:"),  

Whitespace at EOL.

That's fine, though.

Peter