1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
var types = require('./types');
var reader = require('./reader');
var printer = require('./printer');
var Env = require('./env').Env;
var core = require('./core');
if (typeof module !== 'undefined') {
var readline = require('./node_readline');
}
// read
function READ(str) {
return reader.read_str(str);
}
// eval
function is_pair(x) {
return types._sequential_Q(x) && x.length > 0;
}
function quasiquote(ast) {
if (!is_pair(ast)) {
return [types._symbol("quote"), ast];
} else if (ast[0].value === 'unquote') {
return ast[1];
} else if (is_pair(ast[0]) && ast[0][0].value === 'splice-unquote') {
return [types._symbol("concat"), ast[0][1], quasiquote(ast.slice(1))];
} else {
return [types._symbol("cons"), quasiquote(ast[0]), quasiquote(ast.slice(1))];
}
}
function is_macro_call(ast, env) {
return types._list_Q(ast) &&
types._symbol_Q(ast[0]) &&
env.find(ast[0].value) &&
env.get(ast[0].value)._ismacro_;
}
function macroexpand(ast, env) {
while (is_macro_call(ast, env)) {
var mac = env.get(ast[0]);
ast = mac.apply(mac, ast.slice(1));
}
return ast;
}
function eval_ast(ast, env) {
if (types._symbol_Q(ast)) {
return env.get(ast);
} else if (types._list_Q(ast)) {
return ast.map(function(a) { return EVAL(a, env); });
} else if (types._vector_Q(ast)) {
var v = ast.map(function(a) { return EVAL(a, env); });
v.__isvector__ = true;
return v;
} else if (types._hash_map_Q(ast)) {
var new_hm = {};
for (k in ast) {
new_hm[EVAL(k, env)] = EVAL(ast[k], env);
}
return new_hm;
} else {
return ast;
}
}
function _EVAL(ast, env) {
while (true) {
//console.log("EVAL:", types._pr_str(ast, true));
if (!types._list_Q(ast)) {
return eval_ast(ast, env);
}
// apply list
ast = macroexpand(ast, env);
if (!types._list_Q(ast)) { return ast; }
var a0 = ast[0], a1 = ast[1], a2 = ast[2], a3 = ast[3];
switch (a0.value) {
case "def!":
var res = EVAL(a2, env);
return env.set(a1, res);
case "let*":
var let_env = new Env(env);
for (var i=0; i < a1.length; i+=2) {
let_env.set(a1[i].value, EVAL(a1[i+1], let_env));
}
return EVAL(a2, let_env);
case "quote":
return a1;
case "quasiquote":
return EVAL(quasiquote(a1), env);
case 'defmacro!':
var func = EVAL(a2, env);
func._ismacro_ = true;
return env.set(a1, func);
case 'macroexpand':
return macroexpand(a1, env);
case "js*":
return eval(a1.toString());
case ".":
var el = eval_ast(ast.slice(2), env),
f = eval(a1.toString());
return f.apply(f, el);
case "do":
eval_ast(ast.slice(1, -1), env);
ast = ast[ast.length-1];
break;
case "if":
var cond = EVAL(a1, env);
if (cond === null || cond === false) {
ast = (typeof a3 !== "undefined") ? a3 : null;
} else {
ast = a2;
}
break;
case "fn*":
return types._function(EVAL, Env, a2, env, a1);
default:
var el = eval_ast(ast, env), f = el[0], meta = f.__meta__;
if (meta && meta.exp) {
ast = meta.exp;
env = new Env(meta.env, meta.params, el.slice(1));
} else {
return f.apply(f, el.slice(1));
}
}
}
}
function EVAL(ast, env) {
var result = _EVAL(ast, env);
return (typeof result !== "undefined") ? result : null;
}
// print
function PRINT(exp) {
return printer._pr_str(exp, true);
}
// repl
var repl_env = new Env();
var rep = function(str) { return PRINT(EVAL(READ(str), repl_env)); };
_ref = function (k,v) { repl_env.set(k, v); }
// Import core functions
for (var n in core.ns) { repl_env.set(n, core.ns[n]); }
_ref('read-string', reader.read_str);
_ref('eval', function(ast) { return EVAL(ast, repl_env); });
_ref('slurp', function(f) {
return require('fs').readFileSync(f, 'utf-8');
});
// Defined using the language itself
rep("(def! not (fn* (a) (if a false true)))");
rep("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))");
if (typeof process !== 'undefined' && process.argv.length > 2) {
for (var i=2; i < process.argv.length; i++) {
rep('(load-file "' + process.argv[i] + '")');
}
} else if (typeof require === 'undefined') {
// Asynchronous browser mode
readline.rlwrap(function(line) { return rep(line); },
function(exc) {
if (exc instanceof reader.BlankException) { return; }
if (exc.stack) { console.log(exc.stack); } else { console.log(exc); }
});
} else if (require.main === module) {
// Synchronous node.js commandline mode
while (true) {
var line = readline.readline("user> ");
if (line === null) { break; }
try {
if (line) { console.log(rep(line)); }
} catch (exc) {
if (exc instanceof reader.BlankException) { continue; }
if (exc.stack) { console.log(exc.stack); } else { console.log(exc); }
}
}
} else {
exports.rep = rep;
}
|
