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32d0a1cf | 1 | import Compat; |
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2 | import types.Types.MalType; |
3 | import types.Types.*; | |
dd7a4f55 | 4 | import types.MalException; |
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5 | import reader.*; |
6 | import printer.*; | |
7 | import env.*; | |
8 | import core.*; | |
9 | ||
10 | class Step8_macros { | |
11 | // READ | |
12 | static function READ(str:String):MalType { | |
13 | return Reader.read_str(str); | |
14 | } | |
15 | ||
16 | // EVAL | |
17 | static function is_pair(ast:MalType) { | |
18 | return switch (ast) { | |
19 | case MalList(l) | MalVector(l): l.length > 0; | |
20 | case _: false; | |
21 | } | |
22 | } | |
23 | ||
24 | static function quasiquote(ast:MalType) { | |
25 | if (!is_pair(ast)) { | |
26 | return MalList([MalSymbol("quote"), ast]); | |
27 | } else { | |
28 | var a0 = first(ast); | |
29 | if (_equal_Q(a0, MalSymbol("unquote"))) { | |
30 | return _nth(ast, 1); | |
31 | } else if (is_pair(a0)) { | |
32 | var a00 = first(a0); | |
33 | if (_equal_Q(a00, MalSymbol("splice-unquote"))) { | |
34 | return MalList([MalSymbol("concat"), | |
35 | _nth(a0, 1), | |
36 | quasiquote(rest(ast))]); | |
37 | } | |
38 | } | |
39 | return MalList([MalSymbol("cons"), | |
40 | quasiquote(a0), | |
41 | quasiquote(rest(ast))]); | |
42 | } | |
43 | } | |
44 | ||
45 | static function is_macro(ast:MalType, env:Env) { | |
46 | return switch(ast) { | |
d3ec2994 | 47 | case MalList([]): false; |
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48 | case MalList(a): |
49 | var a0 = a[0]; | |
50 | return symbol_Q(a0) && | |
51 | env.find(a0) != null && | |
52 | _macro_Q(env.get(a0)); | |
53 | case _: false; | |
54 | } | |
55 | } | |
56 | ||
57 | static function macroexpand(ast:MalType, env:Env) { | |
58 | while (is_macro(ast, env)) { | |
59 | var mac = env.get(first(ast)); | |
60 | switch (mac) { | |
61 | case MalFunc(f,_,_,_,_,_): | |
62 | ast = f(_list(ast).slice(1)); | |
63 | case _: break; | |
64 | } | |
65 | } | |
66 | return ast; | |
67 | } | |
68 | ||
69 | static function eval_ast(ast:MalType, env:Env) { | |
70 | return switch (ast) { | |
71 | case MalSymbol(s): env.get(ast); | |
72 | case MalList(l): | |
73 | MalList(l.map(function(x) { return EVAL(x, env); })); | |
74 | case MalVector(l): | |
75 | MalVector(l.map(function(x) { return EVAL(x, env); })); | |
76 | case MalHashMap(m): | |
77 | var new_map = new Map<String,MalType>(); | |
78 | for (k in m.keys()) { | |
79 | new_map[k] = EVAL(m[k], env); | |
80 | } | |
81 | MalHashMap(new_map); | |
82 | case _: ast; | |
83 | } | |
84 | } | |
85 | ||
86 | static function EVAL(ast:MalType, env:Env):MalType { | |
87 | while (true) { | |
88 | if (!list_Q(ast)) { return eval_ast(ast, env); } | |
89 | ||
90 | // apply | |
91 | ast = macroexpand(ast, env); | |
33dec7af | 92 | if (!list_Q(ast)) { return eval_ast(ast, env); } |
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93 | |
94 | var alst = _list(ast); | |
d3ec2994 | 95 | if (alst.length == 0) { return ast; } |
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96 | switch (alst[0]) { |
97 | case MalSymbol("def!"): | |
98 | return env.set(alst[1], EVAL(alst[2], env)); | |
99 | case MalSymbol("let*"): | |
100 | var let_env = new Env(env); | |
101 | switch (alst[1]) { | |
102 | case MalList(l) | MalVector(l): | |
103 | for (i in 0...l.length) { | |
104 | if ((i%2) > 0) { continue; } | |
105 | let_env.set(l[i], EVAL(l[i+1], let_env)); | |
106 | } | |
107 | case _: throw "Invalid let*"; | |
108 | } | |
109 | ast = alst[2]; | |
110 | env = let_env; | |
111 | continue; // TCO | |
112 | case MalSymbol("quote"): | |
113 | return alst[1]; | |
114 | case MalSymbol("quasiquote"): | |
115 | ast = quasiquote(alst[1]); | |
116 | continue; // TCO | |
117 | case MalSymbol("defmacro!"): | |
118 | var func = EVAL(alst[2], env); | |
119 | return switch (func) { | |
120 | case MalFunc(f,ast,e,params,_,_): | |
121 | env.set(alst[1], MalFunc(f,ast,e,params,true,nil)); | |
122 | case _: | |
123 | throw "Invalid defmacro! call"; | |
124 | } | |
125 | case MalSymbol("macroexpand"): | |
126 | return macroexpand(alst[1], env); | |
127 | case MalSymbol("do"): | |
128 | var el = eval_ast(MalList(alst.slice(1, alst.length-1)), env); | |
129 | ast = last(ast); | |
130 | continue; // TCO | |
131 | case MalSymbol("if"): | |
132 | var cond = EVAL(alst[1], env); | |
133 | if (cond != MalFalse && cond != MalNil) { | |
134 | ast = alst[2]; | |
135 | } else if (alst.length > 3) { | |
136 | ast = alst[3]; | |
137 | } else { | |
138 | return MalNil; | |
139 | } | |
140 | continue; // TCO | |
141 | case MalSymbol("fn*"): | |
142 | return MalFunc(function (args) { | |
143 | return EVAL(alst[2], new Env(env, _list(alst[1]), args)); | |
144 | },alst[2],env,alst[1],false,nil); | |
145 | case _: | |
146 | var el = eval_ast(ast, env); | |
147 | var lst = _list(el); | |
148 | switch (first(el)) { | |
149 | case MalFunc(f,a,e,params,_,_): | |
150 | var args = _list(el).slice(1); | |
151 | if (a != null) { | |
152 | ast = a; | |
153 | env = new Env(e, _list(params), args); | |
154 | continue; // TCO | |
155 | } else { | |
156 | return f(args); | |
157 | } | |
158 | case _: throw "Call of non-function"; | |
159 | } | |
160 | } | |
161 | } | |
162 | } | |
163 | ||
164 | ||
165 | static function PRINT(exp:MalType):String { | |
166 | return Printer.pr_str(exp, true); | |
167 | } | |
168 | ||
169 | // repl | |
170 | static var repl_env = new Env(null); | |
171 | ||
172 | static function rep(line:String):String { | |
173 | return PRINT(EVAL(READ(line), repl_env)); | |
174 | } | |
175 | ||
176 | public static function main() { | |
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177 | // core.EXT: defined using Haxe |
178 | for (k in Core.ns.keys()) { | |
179 | repl_env.set(MalSymbol(k), MalFunc(Core.ns[k],null,null,null,false,nil)); | |
180 | } | |
181 | ||
182 | var evalfn = MalFunc(function(args) { | |
183 | return EVAL(args[0], repl_env); | |
184 | },null,null,null,false,nil); | |
185 | repl_env.set(MalSymbol("eval"), evalfn); | |
186 | ||
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187 | var cmdargs = Compat.cmdline_args(); |
188 | var argarray = cmdargs.map(function(a) { return MalString(a); }); | |
17946efb | 189 | repl_env.set(MalSymbol("*ARGV*"), MalList(argarray.slice(1))); |
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190 | |
191 | // core.mal: defined using the language itself | |
192 | rep("(def! not (fn* (a) (if a false true)))"); | |
193 | rep("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"); | |
194 | rep("(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"); | |
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195 | |
196 | ||
197 | if (cmdargs.length > 0) { | |
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198 | rep('(load-file "${cmdargs[0]}")'); |
199 | Compat.exit(0); | |
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200 | } |
201 | ||
202 | while (true) { | |
203 | try { | |
32d0a1cf | 204 | var line = Compat.readline("user> "); |
1d166495 | 205 | if (line == "") { continue; } |
32d0a1cf | 206 | Compat.println(rep(line)); |
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207 | } catch (exc:BlankLine) { |
208 | continue; | |
209 | } catch (exc:haxe.io.Eof) { | |
32d0a1cf | 210 | Compat.exit(0); |
1d166495 | 211 | } catch (exc:Dynamic) { |
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212 | if (Type.getClass(exc) == MalException) { |
213 | Compat.println("Error: " + Printer.pr_str(exc.obj, true)); | |
214 | } else { | |
215 | Compat.println("Error: " + exc); | |
216 | }; | |
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217 | } |
218 | } | |
219 | } | |
220 | } |