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38 lines
1.1 KiB
Racket
38 lines
1.1 KiB
Racket
9 years ago
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#lang racket/base
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(provide [struct-out token-struct]
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token
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[struct-out exn:fail:parsing])
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(struct token-struct (type val offset line column span skip?)
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#:transparent)
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;; Token constructor.
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;; This is intended to be a general token structure constructor that's nice
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;; to work with.
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;; It should cooperate with the tokenizers constructed with make-permissive-tokenizer.
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(define token
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(lambda (type ;; (U symbol string)
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[val #f] ;; any
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#:offset [offset #f] ;; (U #f number)
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#:line [line #f] ;; (U #f number)
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#:column [column #f] ;; (U #f number)
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#:span [span #f] ;; boolean
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#:skip? [skip? #f])
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(token-struct (if (string? type) (string->symbol type) type)
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val
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offset line column span skip?)))
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;; When bad things happen, we need to emit errors with source location.
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(struct exn:fail:parsing exn:fail (srclocs)
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#:transparent
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#:property prop:exn:srclocs (lambda (instance)
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(exn:fail:parsing-srclocs instance)))
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