racket/step0_repl.rkt

   1 #!/usr/bin/env racket
   2 #lang racket
   3
   4 (require "readline.rkt" "types.rkt")
   5
   6 ;; read
   7 (define (READ str)
   8   str)
   9
  10 ;; eval
  11 (define (EVAL ast env)
  12   ast)
  13
  14 ;; print
  15 (define (PRINT exp)
  16   exp)
  17
  18 ;; repl
  19 (define (rep str)
  20   (PRINT (EVAL (READ str) "")))
  21
  22 (define (repl-loop)
  23   (let ([line (readline "user> ")])
  24     (when (not (eq? nil line))
  25       (printf "~a~n" (rep line))
  26       (repl-loop))))
  27 (repl-loop)