[plt-scheme] match single symbol
Sam TH wrote:
> On Thu, Sep 3, 2009 at 12:28 AM, Jon Rafkind<rafkind at cs.utah.edu> wrote:
>
>>> What have literals (which compare against a single value) got to do
>>> with predicates (which often match a whole class of values)?
>>>
>>> --Carl
>>>
>>>
>> Er yea, sorry I was totally confused for a second. I'll just write my own
>> matchers with define-match-expander.
>>
>
> For literals, 'foo, 7, "hello", and such all work fine. What doesn't
> exist at the moment that you need?
>
>
I need to match any single symbol and got momentarily confused about the
literal patterns. I thought there was a pattern for matching any string,
but its just a literal string.
This is essentially what I need:
(define-match-expander symbol (lambda (stx) #'(? symbol?)))
(match 'x
[symbol 'ok]
[else 'bad])