Re: `compare-strings' style question

[Andreas Politz]

tomas@tuxteam.de writes:

> On Thu, Nov 19, 2009 at 12:39:33PM +0100, David Kastrup wrote:
>> tomas@tuxteam.de writes:
>> 
>> > Hi,
>> >
>> > In Elisp, I'm trying to test whether a string is a prefix of another.
>
> [...]
>
>> >   (when (eq (compare-strings foo 0 5 bar 0 5) t)
>> >     ...)
>> >
>> > which looks rather funny. My question: are there better idioms? Am I
>> > barking up the wrong function?
>> 
>> (unless (numberp ...
>> 
>> or
>> 
>> (if (symbolp ...
>
> Thanks. Still looks a bit funna, though :-)
>
> -- tomás

(defun string-prefixp (string prefix &optional ignore-case)
  "Return t if PREFIX is a prefix of STRING."
  (eq t
        (compare-strings string 0 (length prefix)
                         prefix 0 (length prefix)
                         ignore-case)))

I defined this function in one of my elisp files.  Why don't you do just
the same ? Where is the problem.

-ap