Re: [PATCH] Improved source properties and errors; => within case

[Andy Wingo]

Heya Mark,

Patch set looks good to me.  Please push.  One comment:

On Wed 08 Feb 2012 10:09, Mark H Weaver <address@hidden> writes:

>  The way that source properties are stored means that Guile can only
> -associate source properties with parenthesized expressions, and not, for
> -example, with individual symbols, numbers or strings.  The difference
> -can be seen by typing @code{(xxx)} and @code{xxx} at the Guile prompt
> -(where the variable @code{xxx} has not been defined):
> +associate source properties with parenthesized expressions and non-empty
> +strings, and not, for example, with individual symbols or numbers.  The
> +difference can be seen by typing @code{(xxx)} and @code{xxx} at the
> +Guile prompt (where the variable @code{xxx} has not been defined):

This isn't quite right; #*101010101 should probably get source info, no?
And is it useful to have an exception for empty strings?  I would think
that it would be fine to return fresh empty strings.  The compiler would
DTRT.  I don't care much though.

Perhaps: "Everything but numbers, symbols, characters, and booleans get
source information."  Dunno.

> +    (syntax-case whole-expr ()
> +      ((_ clause clauses ...)
> +       #`(begin

(This is in `cond').  Why is the begin needed here?

> +                            #`((let ((t test))
> +                                 (if t t #,@tail)))))

Use `or' here.

> +    (syntax-case whole-expr ()
> +      ((_ expr clause clauses ...)
> +       (with-syntax ((key #'key))
> +         #`(let ((key expr))
> +             #,@(fold

(In `case'.)  Likewise here, it would be good to avoid this use of an
implicit `begin', of possible.

> +                                      (if (memv datum seen)
> +                                          (warn-datum 'duplicate-case-datum))
> +                                      (if (or (pair? datum)
> +                                              (array? datum)
> +                                              (generalized-vector? datum))
> +                                          (warn-datum 'bad-case-datum))

Nice.

Cheers,

Andy
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