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