41 lines
1.4 KiB
Plaintext
41 lines
1.4 KiB
Plaintext
(define (split-params bindings params)
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(cond ((null? bindings) params)
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(#t (split-params (cdr bindings)
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(append params (cons (caar bindings) '()))))))
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(define (split-values bindings values)
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(cond ((null? bindings) values)
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(#t (split-values (cdr bindings)
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(append values (cdar bindings) '())))))
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(define-macro (simple-let bindings rest)
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`((lambda ,(split-params bindings '()) ,@rest)
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,@(split-values bindings '())))
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(define-macro (let-loop label bindings . rest)
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`(let ((,label *unspecified*))
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(let ((,label (lambda ,(split-params bindings '()) ,@rest)))
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(,label ,@(split-values bindings '())))))
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(define-macro (let-loop label bindings rest)
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`((lambda (,label)
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(display "loop") (newline)
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(set! ,label (lambda ,(split-params bindings '()) ,@rest))
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(,label ,@(split-values bindings '())))
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*unspecified*))
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(define-macro (let bindings-or-label . rest)
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`(cond (,(symbol? bindings-or-label)
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(let-loop ,bindings-or-label ,(car rest) ,(cdr rest)))
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(#t (simple-let ,bindings-or-label ,rest))))
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(display (let ((a "b"))
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(display "A: ") (display a) (newline) a))
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(display (let loop ((lst '(1 2 3)))
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(display "LOOP")
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(newline)
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(cond ((null? lst) '(dun))
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(#t (cons (car lst) (loop (cdr lst)))))))
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(newline)
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