
25 Feb
2008
25 Feb
'08
9:50 p.m.
Hi Edi, 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? Cheers, Andy