]> Rafael 'Dido' Sevilla writes: > Now I'm stuck again. I'm revising the lexical analyzer for my compiler > to enable it to recognize escaped strings, with conventions different > from OCaml's. Currently, I'm using this regex: > > '\'' ("\\\\"|"\\'"|[^'\''])* '\'' > > in an attempt to recognize strings that begin and end with single > quotes, but may possibly include sequences like \' that represent > escaped quotes, and '\\' that represent escaped backslashes. Of course, > this doesn't work, as I lately realized, because this string: > > '\\' '\\' > > looks like I'm escaping the second quote, so I wind up with an empty > token. Any hints on how I'd go about doing this sort of thing? This should work: '\'' ([^'\'' '\\'] | '\\' _)* '\'' i.e. any backslash in the string must be followed by a character (whatever its interpretation is). You can be more precise if backslashes must be followed by \ or ' and nothing else. Then the regexp is '\'' ([^'\'' '\\'] | '\\' ('\\' | '\''))* '\'' (For instance ocaml strings conform to the former, but a warning is emitted whenever the character following \ has no particular interpretation). -- Jean-Christophe ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners