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28 lines
568 B
Racket
28 lines
568 B
Racket
#lang racket/base
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(provide tokenize)
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;; A simple lexer for simple-line-drawing.
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(require brag/support
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br-parser-tools/lex)
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(define (tokenize ip)
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(port-count-lines! ip)
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(define my-lexer
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(lexer-src-pos
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[(repetition 1 +inf.0 numeric)
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(token 'INTEGER (string->number lexeme))]
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[upper-case
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(token 'STRING lexeme)]
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["b"
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(token 'STRING " ")]
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[";"
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(token ";" lexeme)]
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[whitespace
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(token 'WHITESPACE lexeme #:skip? #t)]
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[(eof)
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(void)]))
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(define (next-token) (my-lexer ip))
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next-token)
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