[erlang-questions] Strings as Lists

Christian S <>
Thu Feb 14 01:09:39 CET 2008


> > Leex is very cool and I have been playing with it some. It generates
> > erlang code which is good. I mostly see it as the solution for parsing
> > files.
>
> Leex works anything, it assumes the input is a list of integers.

Oh sure, but with a state-stack one can suddenly parse more than
regular grammars.

Parsing a quoted string as a token from leex is difficult if you know
that the end-quote might not be included in the chunk you just fed
into leex, but the next chunk read from the tcp stream.

With fully recursive grammars I can see how one wants to let yecc
handle it, but a quoted string is not really recursive: You cant have
a quoted string inside a quoted string the same way you can have, say,
an if-expression inside an if-expression inside an if-expression etc
in a programming language.

Leex is a tool I would use for when I know I have some file of finite
length and I could do a two-pass parsing with yecc as the second
stage, I would not use it for tokenizing SMTP/IRC/NNTP...

I'm looking for a better tool (as in quicker and easier code to
maintain/extend) than writing protocol parsing "by hand".

PS.
I reserve the right to be completly mistaken about everything.



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