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#lang br
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(require brag/support)
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(define-lex-abbrev digits (:+ (char-set "0123456789")))
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(define basic-lexer
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(lexer-srcloc
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[(eof) (return-without-srcloc eof)]
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[whitespace (token lexeme #:skip? #t)]
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[(from/to "rem" "\n") (token 'REM lexeme)]
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[(:or "print" "goto" "end" "+" ":") lexeme]
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[digits (token 'INTEGER (string->number lexeme))]
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[(:or (:seq digits ".") (:seq (:? digits) "." digits))
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(token 'DECIMAL (string->number lexeme))]
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[(from/to "\"" "\"")
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(token 'STRING (trim-ends "\"" lexeme "\""))]))
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(provide basic-lexer)
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