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31 lines
829 B
Racket
31 lines
829 B
Racket
#lang br
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(provide (all-defined-out))
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;; b-sum : b-product (("+" | "-") b-product)*
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(define-macro-cases b-sum
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[(_ PROD) #'PROD]
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[(_ LEFT-PROD "+" RIGHT-PROD) #'(+ LEFT-PROD RIGHT-PROD)]
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[(_ LEFT-PROD "-" RIGHT-PROD) #'(- LEFT-PROD RIGHT-PROD)])
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;; b-product : [b-product ("*"|"/"|"%"|"^")] b-value
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(define-macro-cases b-product
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[(_ VAL) #'VAL]
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[(_ LEFT "*" RIGHT) #'(* LEFT RIGHT)]
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[(_ LEFT "/" RIGHT) #'(/ LEFT RIGHT 1.0)]
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[(_ LEFT "mod" RIGHT) #'(modulo LEFT RIGHT)])
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;; b-expt : [b-expt "^"] b-value
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(define-macro-cases b-expt
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[(_ VAL) #'VAL]
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[(_ LEFT "^" RIGHT) #'(expt LEFT RIGHT)])
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(define (b-expr expr)
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(if (integer? expr) (inexact->exact expr) expr))
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(define (b-negative num) (- num))
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(define (b-not expr) (if (zero? expr) 1 0))
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(define-macro (b-def ID VAR EXPR)
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#'(set! ID (λ (VAR) EXPR)))
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