how to handle lookahead in JLex?

I'm using JLex to write a lexer for M. I have a case that calls for
lookahead, which JLex doesn't support. For example, consider this
line of code:


        write $p($p,",")


The first "$p" is an abbreviated form of the special function
"$piece." The second "$p" is an abbreviated form of the special
variable "$principal." I'd like the lexer to be smart enough to tell
the difference, and it's easy with lookahead: functions are always
followed by an open paren.


Some other lex features that JLex appears to lack are: input(),
unput(c), and REJECT. The generated lexer uses BufferedReader. I
haven't had any luck replacing it with PushbackReader.


I'm not ready to jump ship to JavaCC or ANTLR yet. Any suggestions?


--Jon


Jon Willeke <jwilleke@ix.netcom.com>

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