#lang racket/base (require parser-tools/lex ragg/support) (provide tokenize) (define (tokenize ip) (port-count-lines! ip) (define lex (lexer [(char-set "><-.,+[]") lexeme] [whitespace (token 'white #:skip? #t)] [(eof) (void)])) (define next-token-func (λ _ (lex ip))) next-token-func)