mirror of
https://github.com/kanaka/mal.git
synced 2024-10-26 22:28:26 +03:00
108 lines
3.5 KiB
Scheme
108 lines
3.5 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)
|
|
(srfi srfi-1) (ice-9 receive) (env) (core) (types))
|
|
|
|
(define *toplevel*
|
|
(receive (b e) (unzip2 core.ns)
|
|
(make-Env #:binds b #:exprs e)))
|
|
|
|
(define (READ str)
|
|
(read_str str))
|
|
|
|
(define (eval_ast ast env)
|
|
(define (_eval x) (EVAL x env))
|
|
(match ast
|
|
((? _nil? obj) obj)
|
|
((? symbol? sym) (env-has sym env))
|
|
((? list? lst) (map _eval lst))
|
|
((? vector? vec) (vector-map (lambda (i x) (_eval x)) vec))
|
|
((? hash-table? ht)
|
|
(define new-ht (make-hash-table))
|
|
(hash-for-each (lambda (k v) (hash-set! new-ht k (_eval v))) ht)
|
|
new-ht)
|
|
(else ast)))
|
|
|
|
(define (eval_seq ast env)
|
|
(cond
|
|
((null? ast) nil)
|
|
((null? (cdr ast)) (EVAL (car ast) env))
|
|
(else
|
|
(EVAL (car ast) env)
|
|
(eval_seq (cdr ast) env))))
|
|
|
|
(define (EVAL ast env)
|
|
(define (%unzip2 kvs)
|
|
(let lp((next kvs) (k '()) (v '()))
|
|
(cond
|
|
;; NOTE: reverse is very important here!
|
|
((null? next) (values (reverse k) (reverse v)))
|
|
((null? (cdr next))
|
|
(throw 'mal-error (format #f "let*: Invalid binding form '~a'" kvs)))
|
|
(else (lp (cddr next) (cons (car next) k) (cons (cadr next) v))))))
|
|
(match ast
|
|
((? non-list?) (eval_ast ast env))
|
|
(() ast)
|
|
(('def! k v) ((env 'set) k (EVAL v env)))
|
|
(('let* kvs body)
|
|
(let* ((new-env (make-Env #:outer env))
|
|
(setter (lambda (k v) ((new-env 'set) k (EVAL v new-env)))))
|
|
(receive (keys vals) (%unzip2 (->list kvs))
|
|
(for-each setter keys vals))
|
|
(EVAL body new-env)))
|
|
(('do rest ...)
|
|
(eval_seq rest env))
|
|
(('if cnd thn els ...)
|
|
(cond
|
|
((and (not (null? els)) (not (null? (cdr els))))
|
|
;; Invalid `if' form
|
|
(throw 'mal-error
|
|
(format #f "if: failed to match any pattern in form '~a'" ast)))
|
|
((cond-true? (EVAL cnd env)) (EVAL thn env))
|
|
(else (if (null? els) nil (EVAL (car els) env)))))
|
|
(('fn* params body ...) ; function definition
|
|
(lambda args
|
|
(eval_seq body (make-Env #:outer env #:binds (->list params) #:exprs args))))
|
|
(else
|
|
(let ((el (map (lambda (x) (EVAL x env)) ast)))
|
|
(apply (car el) (cdr el))))))
|
|
|
|
(define (EVAL-string str)
|
|
(EVAL (read_str str) *toplevel*))
|
|
|
|
(define (PRINT exp)
|
|
(and (not (eof-object? exp))
|
|
(format #t "~a~%" (pr_str exp #t))))
|
|
|
|
(define (LOOP continue?)
|
|
(and continue? (REPL)))
|
|
|
|
(define (REPL)
|
|
(LOOP
|
|
(let ((line (_readline "user> ")))
|
|
(cond
|
|
((eof-object? line) #f)
|
|
((string=? line "") #t)
|
|
(else
|
|
(catch 'mal-error
|
|
(lambda () (PRINT (EVAL (READ line) *toplevel*)))
|
|
(lambda (k . e)
|
|
(format #t "Error: ~a~%" (pr_str (car e) #t)))))))))
|
|
|
|
(EVAL-string "(def! not (fn* (x) (if x false true)))")
|
|
|
|
(REPL)
|