Re: [Chicken-users] regex diff + how to check for foreign type?

[felix]

Joerg F. Wittenberger wrote:
> Hi all,
>
> it occured to me that the chicken regex module doesn't allow to
> precompile regualr expressions.  Here some modifications which
> apparently work.  Coding took me to the question how do I check for a
> foreign type.  This code allows to use strings or precompiled regular
> expressions.  But it only checks for strings and assumes otherwise the
> argument to be a precompiled expression.  How could I improve the
> situation?

You could check for a foreign-pointer object. But safer would be
to wrap the pointer in a record:

(define-record compiled-regex ptr)

...
(set! regex-compile
  (lambda (str) (make-compiled-regex (##regexp#compile str)) )
...

  (cond [(compiled-regex? x) ...]
        [(string? x) ...]
        [else <error>...] )


Thanks for the code, I'll check this out and add it to the
regex unit, if possible.


cheers,
felix