31 lines
1.3 KiB
Racket
31 lines
1.3 KiB
Racket
#lang racket
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(require "structures.rkt")
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(provide/contract
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[eliminate-whitespace ((listof symbol?) (boolean? . -> . boolean?) . -> . (element? . -> . element?))])
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;; eliminate-whitespace : (listof Symbol) (Bool -> Bool) -> Element -> Element
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(define (eliminate-whitespace special eliminate-special?)
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(letrec ([blank-it
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(lambda (el)
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(let ([name (element-name el)]
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[content (map (lambda (x)
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(if (element? x) (blank-it x) x))
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(element-content el))])
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(make-element
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(source-start el)
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(source-stop el)
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name
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(element-attributes el)
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(cond
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[(eliminate-special? (and (memq (element-name el) special) #t))
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(filter (lambda (s)
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(not (and (pcdata? s)
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(or (all-blank (pcdata-string s))
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(error 'eliminate-blanks "Element <~a> is not allowed to contain text ~e" name (pcdata-string s))))))
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content)]
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[else content]))))])
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blank-it))
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;; all-blank : String -> Bool
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(define (all-blank s) (andmap char-whitespace? (string->list s)))
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