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f5223195 JM |
1 | --- step7_quote --------------------------------- |
2 | import types, reader, printer, env, core | |
3 | ||
4 | READ(str): return reader.read_str(str) | |
5 | ||
f5223195 JM |
6 | quasiquote(ast): return ... // quasiquote |
7 | ||
8 | eval_ast(ast,env): | |
9 | switch type(ast): | |
10 | symbol: return env.get(ast) | |
11 | list,vector: return ast.map((x) -> EVAL(x,env)) | |
12 | hash: return ast.map((k,v) -> list(k, EVAL(v,env))) | |
13 | _default_: return ast | |
14 | ||
15 | EVAL(ast,env): | |
16 | while true: | |
17 | if not list?(ast): return eval_ast(ast, env) | |
1d100977 | 18 | if empty?(ast): return ast |
f5223195 JM |
19 | switch ast[0]: |
20 | 'def!: return env.set(ast[1], EVAL(ast[2], env)) | |
21 | 'let*: env = ...; ast = ast[2] // TCO | |
22 | 'quote: return ast[1] | |
23 | 'quasiquote: ast = quasiquote(ast[1]) // TCO | |
24 | 'do: ast = eval_ast(ast[1..-1], env)[-1] // TCO | |
25 | 'if: EVAL(ast[1], env) ? ast = ast[2] : ast = ast[3] // TCO | |
26 | 'fn*: return new MalFunc(...) | |
27 | _default_: f, args = eval_ast(ast, env) | |
899ff7fa JM |
28 | if malfunc?(f): ast = f.fn; env = ... // TCO |
29 | else: return apply(f, args) | |
f5223195 JM |
30 | |
31 | PRINT(exp): return printer.pr_str(exp) | |
32 | ||
33 | repl_env = new Env() | |
34 | rep(str): return PRINT(EVAL(READ(str),repl_env)) | |
35 | ||
36 | ;; core.EXT: defined using Racket | |
37 | core.ns.map((k,v) -> (repl_env.set(k, v))) | |
38 | repl_env.set('eval, (ast) -> EVAL(ast, repl-env)) | |
39 | repl_env.set('*ARGV*, cmdline_args[1..]) | |
40 | ||
41 | ;; core.mal: defined using the language itself | |
42 | rep("(def! not (fn* (a) (if a false true)))") | |
e6d41de4 | 43 | rep("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))") |
f5223195 JM |
44 | |
45 | if cmdline_args: rep("(load-file \"" + args[0] + "\")"); exit 0 | |
46 | ||
47 | main loop: | |
48 | try: println(rep(readline("user> "))) | |
49 | catch e: println("Error: ", e) | |
50 | ||
51 | --- env module ---------------------------------- | |
52 | class Env (outer=null,binds=[],exprs=[]) | |
53 | data = hash_map() | |
54 | foreach b, i in binds: | |
55 | if binds[i] == '&: data[binds[i+1]] = exprs.drop(i); break | |
56 | else: data[binds[i]] = exprs[i] | |
57 | set(k,v): return data.set(k,v) | |
58 | find(k): return data.has(k) ? this : (if outer ? find(outer) : null) | |
59 | get(k): return data.find(k).get(k) OR raise "'" + k + "' not found" | |
fd888612 | 60 | |
f5223195 JM |
61 | --- core module --------------------------------- |
62 | ns = {'=: equal?, | |
f5223195 JM |
63 | |
64 | 'pr-str: (a) -> a.map(|s| pr_str(e,true)).join(" ")), | |
65 | 'str: (a) -> a.map(|s| pr_str(e,false)).join("")), | |
66 | 'prn: (a) -> println(a.map(|s| pr_str(e,true)).join(" ")), | |
67 | 'println: (a) -> println(a.map(|s| pr_str(e,false)).join(" ")), | |
68 | 'read-string: read_str, | |
69 | 'slurp read-file, | |
70 | ||
71 | '<: lt, | |
72 | '<=: lte, | |
73 | '>: gt, | |
74 | '>=: gte, | |
75 | '+: add, | |
76 | '-: sub, | |
77 | '*: mult, | |
78 | '/: div, | |
79 | ||
80 | 'list: list, | |
81 | 'list?: list?, | |
f5223195 JM |
82 | |
83 | 'cons: (a) -> concat([a[0]], a[1]), | |
84 | 'concat: (a) -> reduce(concat, [], a), | |
fbfe6784 | 85 | 'vec: (l) -> l converted to vector, |
f5223195 | 86 | 'empty?: empty?, |
627bd6f7 DM |
87 | 'count: count, |
88 | ||
89 | 'atom: (a) -> new Atom(a[0]), | |
90 | 'atom?: (a) -> type(a[0]) == "atom", | |
91 | 'deref: (a) -> a[0].val, | |
92 | 'reset!: (a) -> a[0].val = a[1], | |
93 | 'swap!: swap!} |