Create stacker-extended.rkt

pull/13/head
Jean Carass 7 years ago committed by GitHub
parent d69757cf85
commit 8a319647f7
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@ -0,0 +1,38 @@
#lang br/quicklang
(define (read-syntax path port)
(define args (port->lines port))
(define handle-datums (format-datums '(handle ~a) args))
(define module-datum `(module stacker-mod stacker-demo/stacker
,@handle-datums))
(datum->syntax #f module-datum))
(provide read-syntax)
(define-macro (stacker-module-begin HANDLE-EXPR ...)
#'(#%module-begin
HANDLE-EXPR ...
(display (first stack))))
(provide (rename-out [stacker-module-begin #%module-begin]))
(define stack empty)
(define (pop-stack!)
(define arg (first stack))
(set! stack (rest stack))
arg)
(define (push-stack! arg)
(set! stack (cons arg stack)))
(define (handle [arg #f])
(cond
[(number? arg) (push-stack! arg)]
[(or (equal? * arg) (equal? + arg) (equal? - arg) (equal? / arg))
; This will ensure that stacker can be extended to support - and / operations while keeping the RPN notation
(define operand2 (pop-stack!))
(define operand1 (pop-stack!))
(define op-result (arg operand1 operand2))
(push-stack! op-result)]))
(provide handle)
(provide + * - /)
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