Commit | Line | Data |
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dc9b184b ST |
1 | #include "MAL.h" |
2 | ||
3 | #include "Environment.h" | |
4 | #include "ReadLine.h" | |
5 | #include "Types.h" | |
6 | ||
7 | #include <iostream> | |
8 | #include <memory> | |
9 | ||
10 | malValuePtr READ(const String& input); | |
11 | String PRINT(malValuePtr ast); | |
12 | ||
13 | static ReadLine s_readLine("~/.mal-history"); | |
14 | ||
494c1608 ST |
15 | static malEnvPtr replEnv(new malEnv); |
16 | ||
dc9b184b ST |
17 | int main(int argc, char* argv[]) |
18 | { | |
19 | String prompt = "user> "; | |
20 | String input; | |
dc9b184b ST |
21 | installCore(replEnv); |
22 | while (s_readLine.get(prompt, input)) { | |
23 | String out; | |
24 | try { | |
25 | out = rep(input, replEnv); | |
26 | } | |
27 | catch (malEmptyInputException&) { | |
28 | continue; // no output | |
29 | } | |
30 | catch (String& s) { | |
31 | out = s; | |
32 | }; | |
33 | std::cout << out << "\n"; | |
34 | } | |
35 | return 0; | |
36 | } | |
37 | ||
38 | String rep(const String& input, malEnvPtr env) | |
39 | { | |
40 | return PRINT(EVAL(READ(input), env)); | |
41 | } | |
42 | ||
43 | malValuePtr READ(const String& input) | |
44 | { | |
45 | return readStr(input); | |
46 | } | |
47 | ||
48 | malValuePtr EVAL(malValuePtr ast, malEnvPtr env) | |
49 | { | |
494c1608 ST |
50 | if (!env) { |
51 | env = replEnv; | |
52 | } | |
dc9b184b ST |
53 | const malList* list = DYNAMIC_CAST(malList, ast); |
54 | if (!list || (list->count() == 0)) { | |
55 | return ast->eval(env); | |
56 | } | |
57 | ||
58 | // From here on down we are evaluating a non-empty list. | |
59 | // First handle the special forms. | |
60 | if (const malSymbol* symbol = DYNAMIC_CAST(malSymbol, list->item(0))) { | |
61 | String special = symbol->value(); | |
62 | int argCount = list->count() - 1; | |
63 | ||
64 | if (special == "def!") { | |
65 | checkArgsIs("def!", 2, argCount); | |
66 | const malSymbol* id = VALUE_CAST(malSymbol, list->item(1)); | |
67 | return env->set(id->value(), EVAL(list->item(2), env)); | |
68 | } | |
69 | ||
70 | if (special == "let*") { | |
71 | checkArgsIs("let*", 2, argCount); | |
72 | const malSequence* bindings = | |
73 | VALUE_CAST(malSequence, list->item(1)); | |
74 | int count = checkArgsEven("let*", bindings->count()); | |
75 | malEnvPtr inner(new malEnv(env)); | |
76 | for (int i = 0; i < count; i += 2) { | |
77 | const malSymbol* var = | |
78 | VALUE_CAST(malSymbol, bindings->item(i)); | |
79 | inner->set(var->value(), EVAL(bindings->item(i+1), inner)); | |
80 | } | |
81 | return EVAL(list->item(2), inner); | |
82 | } | |
83 | } | |
84 | ||
85 | // Now we're left with the case of a regular list to be evaluated. | |
86 | std::unique_ptr<malValueVec> items(list->evalItems(env)); | |
87 | malValuePtr op = items->at(0); | |
494c1608 | 88 | return APPLY(op, items->begin()+1, items->end()); |
dc9b184b ST |
89 | } |
90 | ||
91 | String PRINT(malValuePtr ast) | |
92 | { | |
93 | return ast->print(true); | |
94 | } | |
95 | ||
494c1608 | 96 | malValuePtr APPLY(malValuePtr op, malValueIter argsBegin, malValueIter argsEnd) |
dc9b184b ST |
97 | { |
98 | const malApplicable* handler = DYNAMIC_CAST(malApplicable, op); | |
0997015d ST |
99 | MAL_CHECK(handler != NULL, |
100 | "\"%s\" is not applicable", op->print(true).c_str()); | |
dc9b184b | 101 | |
494c1608 | 102 | return handler->apply(argsBegin, argsEnd); |
dc9b184b | 103 | } |
cb252845 ST |
104 | |
105 | // Added to keep the linker happy at step A | |
106 | malValuePtr readline(const String& prompt) | |
107 | { | |
108 | String input; | |
109 | if (s_readLine.get(prompt, input)) { | |
110 | return mal::string(input); | |
111 | } | |
112 | return mal::nilValue(); | |
113 | } | |
114 |