Commit | Line | Data |
---|---|---|
a7081401 HÖS |
1 | use v6; |
2 | use lib IO::Path.new($?FILE).dirname; | |
3 | use reader; | |
4 | use printer; | |
5 | use types; | |
6 | use env; | |
7 | use core; | |
8 | ||
9 | sub read ($str) { | |
10 | return read_str($str); | |
11 | } | |
12 | ||
13 | sub eval_ast ($ast, $env) { | |
14 | given $ast { | |
15 | when MalSymbol { $env.get($ast.val) || die X::MalNotFound.new(name => $ast.val) } | |
16 | when MalList { MalList([$ast.map({ eval($_, $env) })]) } | |
17 | when MalVector { MalVector([$ast.map({ eval($_, $env) })]) } | |
18 | when MalHashMap { MalHashMap($ast.kv.map({ $^a => eval($^b, $env) }).Hash) } | |
19 | default { $ast // $NIL } | |
20 | } | |
21 | } | |
22 | ||
23 | sub is_pair ($ast) { | |
24 | return so $ast ~~ MalList|MalVector && $ast.elems; | |
25 | } | |
26 | ||
27 | sub quasiquote ($ast) { | |
28 | if !is_pair($ast) { | |
29 | return MalList([MalSymbol('quote'), $ast]); | |
30 | } | |
31 | elsif $ast[0] ~~ MalSymbol && $ast[0].val eq 'unquote' { | |
32 | return $ast[1]; | |
33 | } | |
34 | elsif is_pair($ast[0]) && $ast[0][0] ~~ MalSymbol && $ast[0][0].val eq 'splice-unquote' { | |
35 | return MalList([MalSymbol('concat'), $ast[0][1], quasiquote(MalList([$ast[1..*]]))]); | |
36 | } | |
37 | else { | |
38 | return MalList([MalSymbol('cons'), quasiquote($ast[0]), quasiquote(MalList([$ast[1..*]]))]); | |
39 | } | |
40 | } | |
41 | ||
42 | sub eval ($ast is copy, $env is copy) { | |
43 | loop { | |
44 | return eval_ast($ast, $env) if $ast !~~ MalList; | |
45 | return $ast if !$ast.elems; | |
46 | ||
47 | my ($a0, $a1, $a2, $a3) = $ast.val; | |
48 | given $a0.val { | |
49 | when 'def!' { | |
50 | return $env.set($a1.val, eval($a2, $env)); | |
51 | } | |
52 | when 'let*' { | |
53 | my $new_env = MalEnv.new($env); | |
54 | for |$a1.val -> $key, $value { | |
55 | $new_env.set($key.val, eval($value, $new_env)); | |
56 | } | |
57 | $env = $new_env; | |
58 | $ast = $a2; | |
59 | } | |
60 | when 'do' { | |
61 | eval_ast(MalList([$ast[1..*-2]]), $env); | |
62 | $ast = $ast[*-1]; | |
63 | } | |
64 | when 'if' { | |
65 | if eval($a1, $env) ~~ MalNil|MalFalse { | |
66 | return $NIL if $a3 ~~ $NIL; | |
67 | $ast = $a3; | |
68 | } | |
69 | else { | |
70 | $ast = $a2; | |
71 | } | |
72 | } | |
73 | when 'fn*' { | |
74 | my @binds = $a1 ?? $a1.map(*.val) !! (); | |
75 | my &fn = -> *@args { | |
76 | eval($a2, MalEnv.new($env, @binds, @args)); | |
77 | }; | |
78 | return MalFunction($a2, $env, @binds, &fn); | |
79 | } | |
80 | when 'quote' { return $a1 } | |
81 | when 'quasiquote' { $ast = quasiquote($a1) } | |
82 | default { | |
83 | my ($func, @args) = eval_ast($ast, $env).val; | |
84 | return $func.apply(|@args) if $func !~~ MalFunction; | |
85 | $ast = $func.ast; | |
86 | $env = MalEnv.new($func.env, $func.params, @args); | |
87 | } | |
88 | } | |
89 | } | |
90 | } | |
91 | ||
92 | sub print ($exp) { | |
93 | return pr_str($exp, True); | |
94 | } | |
95 | ||
96 | my $repl_env = MalEnv.new; | |
97 | ||
98 | sub rep ($str) { | |
99 | return print(eval(read($str), $repl_env)); | |
100 | } | |
101 | ||
102 | sub MAIN ($source_file?, *@args) { | |
103 | $repl_env.set(.key, .value) for %core::ns; | |
104 | $repl_env.set('eval', MalCode({ eval($^a, $repl_env) })); | |
105 | $repl_env.set('*ARGV*', MalList([@args.map({ MalString($_) })])); | |
106 | rep(q{(def! not (fn* (a) (if a false true)))}); | |
107 | rep(q{(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))}); | |
108 | ||
109 | if ($source_file.defined) { | |
110 | rep("(load-file \"$source_file\")"); | |
111 | exit; | |
112 | } | |
113 | ||
114 | while (my $line = prompt 'user> ').defined { | |
115 | say rep($line); | |
116 | CATCH { | |
117 | when X::MalException { .Str.say } | |
118 | } | |
119 | } | |
120 | } |