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c2b12e5b VS |
1 | (require 'mal/types) |
2 | (require 'mal/reader) | |
3 | (require 'mal/printer) | |
c83a3eeb VS |
4 | |
5 | (defvar repl-env (make-hash-table :test 'eq)) | |
6 | (puthash '+ (lambda (a b) (mal-number (+ (mal-value a) (mal-value b)))) repl-env) | |
7 | (puthash '- (lambda (a b) (mal-number (- (mal-value a) (mal-value b)))) repl-env) | |
8 | (puthash '* (lambda (a b) (mal-number (* (mal-value a) (mal-value b)))) repl-env) | |
9 | (puthash '/ (lambda (a b) (mal-number (/ (mal-value a) (mal-value b)))) repl-env) | |
10 | ||
11 | (defun READ (input) | |
12 | (read-str input)) | |
13 | ||
14 | (defun EVAL (ast env) | |
ecb8de2d | 15 | (if (and (mal-list-p ast) (mal-value ast)) |
c83a3eeb VS |
16 | (let* ((ast* (mal-value (eval-ast ast env))) |
17 | (fn (car ast*)) | |
18 | (args (cdr ast*))) | |
19 | (apply fn args)) | |
20 | (eval-ast ast env))) | |
21 | ||
22 | (defun eval-ast (ast env) | |
23 | (let ((type (mal-type ast)) | |
24 | (value (mal-value ast))) | |
25 | (cond | |
26 | ((eq type 'symbol) | |
27 | (let ((definition (gethash value env))) | |
28 | (or definition (error "Definition not found")))) | |
29 | ((eq type 'list) | |
30 | (mal-list (mapcar (lambda (item) (EVAL item env)) value))) | |
31 | ((eq type 'vector) | |
32 | (mal-vector (vconcat (mapcar (lambda (item) (EVAL item env)) value)))) | |
33 | ((eq type 'map) | |
34 | (let ((map (copy-hash-table value))) | |
35 | (maphash (lambda (key value) | |
36 | (puthash key (EVAL value env) map)) | |
37 | map) | |
38 | (mal-map map))) | |
39 | (t | |
40 | ;; return as is | |
41 | ast)))) | |
42 | ||
43 | (defun PRINT (input) | |
44 | (pr-str input t)) | |
45 | ||
46 | (defun rep (input) | |
47 | (PRINT (EVAL (READ input) repl-env))) | |
48 | ||
49 | (defun readln (prompt) | |
50 | ;; C-d throws an error | |
51 | (ignore-errors (read-from-minibuffer prompt))) | |
52 | ||
53 | (defun println (format-string &rest args) | |
54 | (if (not args) | |
55 | (princ format-string) | |
56 | (princ (apply 'format format-string args))) | |
57 | (terpri)) | |
58 | ||
59 | (defun main () | |
60 | (let (eof) | |
61 | (while (not eof) | |
62 | (let ((input (readln "user> "))) | |
63 | (if input | |
64 | (condition-case err | |
65 | (println (rep input)) | |
66 | (end-of-token-stream | |
67 | ;; empty input, carry on | |
68 | ) | |
69 | (unterminated-sequence | |
70 | (let* ((type (cadr err)) | |
71 | (end | |
72 | (cond | |
73 | ((eq type 'string) ?\") | |
74 | ((eq type 'list) ?\)) | |
75 | ((eq type 'vector) ?\]) | |
76 | ((eq type 'map) ?})))) | |
77 | (princ (format "Expected '%c', got EOF\n" end)))) | |
78 | (error ; catch-all | |
79 | (println (error-message-string err)) | |
80 | (backtrace))) | |
81 | (setq eof t) | |
82 | ;; print final newline | |
83 | (terpri)))))) | |
84 | ||
85 | (main) |