The documentation: http://docs.racket-lang.org/parser-tools/Converting_yacc_or_bison_Grammars.html
says: "Annotated examples are in the "examples" subdirectory of the "parser-tools" collection." That is online here: http://git.racket-lang.org/plt/tree/HEAD:/collects/parser-tools/examples Jay On Tue, Oct 12, 2010 at 12:12 PM, Mark Carter <mcturra2...@yahoo.co.uk> wrote: > Are there any examples on using lex and yacc, as I'm having trouble getting > started. I am trying to write a simple calculator. Here's what I've got so > far: > > #lang racket/base > > (require parser-tools/lex) > > (define lex (lexer > ((:+ "[0-9]") (values 'int (string->number lexeme))) > ((:+ whitespace) null) > ((:: "+") (values 'plus 0)) > ((:: "-") (values 'minus 0)) > ((:: "*") (values 'mult 0)) > ((:: "/") (values 'div 0)))) > > When I try to compile it, I get > regular-expression: undefined operator in: (:+ "[0-9]") > How do I correct this? > > > > > _________________________________________________ > For list-related administrative tasks: > http://lists.racket-lang.org/listinfo/users > -- Jay McCarthy <j...@cs.byu.edu> Assistant Professor / Brigham Young University http://teammccarthy.org/jay "The glory of God is Intelligence" - D&C 93 _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
