56 lines
1.2 KiB
Plaintext
56 lines
1.2 KiB
Plaintext
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;; (display "define-syntax...")
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;; (define-macro define-syntax
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;; (lambda (form expander)
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;; (expander `(define-macro ,(cadr form)
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;; (let ((transformer ,(caddr form)))
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;; (lambda (form expander)
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;; (expander (transformer form
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;; (lambda (x) x)
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;; eq?)
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;; expander))))
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;; expander)))
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;; (newline)
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(display "define-syntax when...")
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;; (define-syntax when
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;; (syntax-rules ()
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;; ((when condition exp ...)
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;; (if condition
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;; (begin exp ...)))))
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;; (define-macro (when cond exp . rest)
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;; `(if ,cond
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;; (begin ,exp . ,rest)))
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;; (define-macro (when clause . rest)
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;; (list 'cond (list clause (list 'let '() rest))))
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(define-macro (when expr . body)
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`(if ,expr
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((lambda () ,@body))
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'bah))
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(newline)
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(when #t
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(display "true")
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(newline))
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(when #t
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(display "q-when")
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(newline)
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'())
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(define *gensym* 0)
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(define (gensym)
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(set! *gensym* (+ *gensym* 1))
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(string->symbol (string-append "g" (number->string *gensym*))))
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(newline)
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