stacker.rkt

Branches > main > 024bf68 > files / nvim / pack / plugins / opt / conjure / dev / racket / stacker.rkt

#lang br/quicklang

;; You need `raco pkg install --auto beautiful-racket` for this.
;; The example comes from https://github.com/Olical/conjure/issues/643

(define (read-syntax path port)
  (define src-lines
    (port->lines port))

  (define src-datums
    (format-datums '(handle ~a) src-lines))

  (define module-datum 
    `(module stacker-mod "stacker.rkt"
       ,@src-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))
     (define op-result
       (arg (pop-stack!) (pop-stack!)))
     (push-stack! op-result)]))

(provide handle)

(provide + *)