mirror of
https://github.com/kanaka/mal.git
synced 2024-09-20 18:18:51 +03:00
69 lines
2.0 KiB
Scheme
69 lines
2.0 KiB
Scheme
;; Copyright (C) 2015
|
|
;; "Mu Lei" known as "NalaGinrut" <NalaGinrut@gmail.com>
|
|
;; This file is free software: you can redistribute it and/or modify
|
|
;; it under the terms of the GNU General Public License as published by
|
|
;; the Free Software Foundation, either version 3 of the License, or
|
|
;; (at your option) any later version.
|
|
|
|
;; This file is distributed in the hope that it will be useful,
|
|
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
;; GNU General Public License for more details.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
(import (readline) (reader) (printer) (ice-9 match) (srfi srfi-43))
|
|
|
|
(define *toplevel*
|
|
`((+ . ,+)
|
|
(- . ,-)
|
|
(* . ,*)
|
|
(/ . ,/)))
|
|
|
|
(define (READ)
|
|
(read_str (_readline "user> ")))
|
|
|
|
(define (eval_ast ast env)
|
|
(define (_eval x) (EVAL x env))
|
|
(match ast
|
|
((? symbol? sym)
|
|
(or (assoc-ref env sym)
|
|
(throw 'mal-error (format #f "'~a' not found" sym))))
|
|
((? list? lst) (map _eval lst))
|
|
((? vector? vec) (vector-map (lambda (i x) (_eval x)) vec))
|
|
((? hash-table? ht)
|
|
(hash-for-each (lambda (k v) (hash-set! ht k (_eval v))) ht)
|
|
ht)
|
|
(else ast)))
|
|
|
|
(define (eval_func ast env)
|
|
(define expr (eval_ast ast env))
|
|
(match expr
|
|
(((? procedure? proc) args ...)
|
|
(apply proc args))
|
|
(else (throw 'mal-error (format #f "'~a' not found" (car expr))))))
|
|
|
|
(define (EVAL ast env)
|
|
(match ast
|
|
((? list?) (eval_func ast env))
|
|
(else (eval_ast ast env))))
|
|
|
|
(define (PRINT exp)
|
|
(and (not (eof-object? exp))
|
|
(format #t "~a~%" (pr_str exp #t))))
|
|
|
|
(define (LOOP continue?)
|
|
(and continue? (REPL)))
|
|
|
|
(define (REPL)
|
|
(LOOP
|
|
(catch 'mal-error
|
|
(lambda () (PRINT (EVAL (READ) *toplevel*)))
|
|
(lambda (k . e)
|
|
(if (string=? (car e) "blank line")
|
|
(display "")
|
|
(format #t "Error: ~a~%" (car e)))))))
|
|
|
|
(REPL)
|