Commit | Line | Data |
---|---|---|
891c3f3b JM |
1 | readline = require "./node_readline.coffee" |
2 | types = require "./types.coffee" | |
3 | reader = require "./reader.coffee" | |
4 | printer = require "./printer.coffee" | |
5 | Env = require("./env.coffee").Env | |
6 | core = require("./core.coffee") | |
7 | ||
8 | # read | |
9 | READ = (str) -> reader.read_str str | |
10 | ||
11 | # eval | |
12 | is_pair = (x) -> types._sequential_Q(x) && x.length > 0 | |
13 | ||
14 | quasiquote = (ast) -> | |
15 | if !is_pair(ast) then [types._symbol('quote'), ast] | |
c963be7a | 16 | else if ast[0] != null && ast[0].name == 'unquote' then ast[1] |
891c3f3b JM |
17 | else if is_pair(ast[0]) && ast[0][0].name == 'splice-unquote' |
18 | [types._symbol('concat'), ast[0][1], quasiquote(ast[1..])] | |
19 | else | |
20 | [types._symbol('cons'), quasiquote(ast[0]), quasiquote(ast[1..])] | |
21 | ||
22 | is_macro_call = (ast, env) -> | |
23 | return types._list_Q(ast) && types._symbol_Q(ast[0]) && | |
b8ee29b2 | 24 | env.find(ast[0]) && env.get(ast[0]).__ismacro__ |
891c3f3b JM |
25 | |
26 | macroexpand = (ast, env) -> | |
27 | while is_macro_call(ast, env) | |
b8ee29b2 | 28 | ast = env.get(ast[0])(ast[1..]...) |
891c3f3b JM |
29 | ast |
30 | ||
31 | ||
32 | ||
33 | eval_ast = (ast, env) -> | |
b8ee29b2 | 34 | if types._symbol_Q(ast) then env.get ast |
891c3f3b JM |
35 | else if types._list_Q(ast) then ast.map((a) -> EVAL(a, env)) |
36 | else if types._vector_Q(ast) | |
37 | types._vector(ast.map((a) -> EVAL(a, env))...) | |
38 | else if types._hash_map_Q(ast) | |
39 | new_hm = {} | |
40 | new_hm[k] = EVAL(ast[k],env) for k,v of ast | |
41 | new_hm | |
42 | else ast | |
43 | ||
44 | EVAL = (ast, env) -> | |
45 | loop | |
46 | #console.log "EVAL:", printer._pr_str ast | |
47 | if !types._list_Q ast then return eval_ast ast, env | |
48 | ||
49 | # apply list | |
bfa3dd35 DM |
50 | ast = macroexpand ast, env |
51 | if !types._list_Q ast then return eval_ast ast, env | |
891c3f3b JM |
52 | |
53 | [a0, a1, a2, a3] = ast | |
54 | switch a0.name | |
55 | when "def!" | |
b8ee29b2 | 56 | return env.set(a1, EVAL(a2, env)) |
891c3f3b JM |
57 | when "let*" |
58 | let_env = new Env(env) | |
59 | for k,i in a1 when i %% 2 == 0 | |
b8ee29b2 | 60 | let_env.set(a1[i], EVAL(a1[i+1], let_env)) |
891c3f3b JM |
61 | ast = a2 |
62 | env = let_env | |
63 | when "quote" | |
64 | return a1 | |
65 | when "quasiquote" | |
66 | ast = quasiquote(a1) | |
67 | when "defmacro!" | |
68 | f = EVAL(a2, env) | |
69 | f.__ismacro__ = true | |
b8ee29b2 | 70 | return env.set(a1, f) |
891c3f3b JM |
71 | when "macroexpand" |
72 | return macroexpand(a1, env) | |
73 | when "try*" | |
74 | try return EVAL(a1, env) | |
75 | catch exc | |
76 | if a2 && a2[0].name == "catch*" | |
77 | if exc instanceof Error then exc = exc.message | |
78 | return EVAL a2[2], new Env(env, [a2[1]], [exc]) | |
79 | else | |
80 | throw exc | |
81 | when "js*" | |
82 | res = eval(a1.toString()) | |
83 | return if typeof(res) == 'undefined' then null else res | |
84 | when "." | |
85 | el = eval_ast(ast[2..], env) | |
86 | return eval(a1.toString())(el...) | |
87 | when "do" | |
88 | eval_ast(ast[1..-2], env) | |
89 | ast = ast[ast.length-1] | |
90 | when "if" | |
91 | cond = EVAL(a1, env) | |
92 | if cond == null or cond == false | |
93 | if a3? then ast = a3 else return null | |
94 | else | |
95 | ast = a2 | |
96 | when "fn*" | |
97 | return types._function(EVAL, a2, env, a1) | |
98 | else | |
99 | [f, args...] = eval_ast ast, env | |
100 | if types._function_Q(f) | |
101 | ast = f.__ast__ | |
102 | env = f.__gen_env__(args) | |
103 | else | |
104 | return f(args...) | |
105 | ||
106 | ||
107 | ||
108 | PRINT = (exp) -> printer._pr_str exp, true | |
109 | ||
110 | # repl | |
111 | repl_env = new Env() | |
112 | rep = (str) -> PRINT(EVAL(READ(str), repl_env)) | |
113 | ||
114 | # core.coffee: defined using CoffeeScript | |
b8ee29b2 JM |
115 | repl_env.set types._symbol(k), v for k,v of core.ns |
116 | repl_env.set types._symbol('eval'), (ast) -> EVAL(ast, repl_env) | |
117 | repl_env.set types._symbol('*ARGV*'), [] | |
891c3f3b JM |
118 | |
119 | # core.mal: defined using the language itself | |
120 | rep("(def! *host-language* \"CoffeeScript\")") | |
121 | rep("(def! not (fn* (a) (if a false true)))"); | |
122 | rep("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"); | |
123 | 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)))))))") | |
166da203 DM |
124 | rep("(def! *gensym-counter* (atom 0))") |
125 | rep("(def! gensym (fn* [] (symbol (str \"G__\" (swap! *gensym-counter* (fn* [x] (+ 1 x)))))))") | |
126 | rep("(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) (let* (condvar (gensym)) `(let* (~condvar ~(first xs)) (if ~condvar ~condvar (or ~@(rest xs)))))))))") | |
891c3f3b JM |
127 | |
128 | if process? && process.argv.length > 2 | |
b8ee29b2 | 129 | repl_env.set types._symbol('*ARGV*'), process.argv[3..] |
891c3f3b JM |
130 | rep('(load-file "' + process.argv[2] + '")') |
131 | process.exit 0 | |
132 | ||
133 | # repl loop | |
134 | rep("(println (str \"Mal [\" *host-language* \"]\"))") | |
135 | while (line = readline.readline("user> ")) != null | |
136 | continue if line == "" | |
137 | try | |
138 | console.log rep line | |
139 | catch exc | |
140 | continue if exc instanceof reader.BlankException | |
4ed89670 JM |
141 | if exc.stack? and exc.stack.length > 2000 |
142 | console.log exc.stack.slice(0,1000) + "\n ..." + exc.stack.slice(-1000) | |
143 | else if exc.stack? console.log exc.stack | |
144 | else console.log exc | |
891c3f3b JM |
145 | |
146 | # vim: ts=2:sw=2 |