[cl-ppcre-devel] alternative to parse-string

[Edi Weitz]

On Mon, 25 Feb 2008 21:50:44 +0000, "Andy Chambers" <achambers.home at googlemail.com> wrote:

> I'm trying to write a lexer where one can use previously defined
> classes in subsequent regular expressions.  For example you'd be
> able to do something like this....
>
> (deflexer my-lexer
>   (ws           "[ \t\n]")
>   (letter       "[a-zA-Z]")
>   (word         (:greedy-repetition 0 nil letter)))
>
> To make this work, the deflexer macro substitutes letter for the
> parse-tree resulting from (parse-string "[a-zA-Z]").  I wrote this
> before realizing that parse-string was not exported.  Is there
> another (more future-proof) way to get at the parse-tree for a regex
> in a way that it can be combined with other trees?

I think it is pretty safe to assume that PARSE-STRING will remain as
it is.  I'll probably just export it in the next release.

Cheers,
Edi.