1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
// This file defines how to compile reductions like `(+: nums)`
#include "../ast.h"
#include "../config.h"
#include "../environment.h"
#include "../stdlib/text.h"
#include "../stdlib/util.h"
#include "../typecheck.h"
#include "compilation.h"
public
Text_t compile_reduction(env_t *env, ast_t *ast) {
DeclareMatch(reduction, ast, Reduction);
ast_e op = reduction->op;
const char *op_str = binop_operator(op);
type_t *iter_t = get_type(env, reduction->iter);
type_t *item_t = get_iterated_type(iter_t);
if (!item_t)
code_err(reduction->iter, "I couldn't figure out how to iterate over this type: ", type_to_str(iter_t));
static int64_t next_id = 1;
ast_t *item = FakeAST(Var, String("$it", next_id++));
ast_t *body = LiteralCode(Text("{}")); // placeholder
ast_t *loop = FakeAST(For, .vars = new (ast_list_t, .ast = item), .iter = reduction->iter, .body = body);
env_t *body_scope = for_scope(env, loop);
if (op == Equals || op == NotEquals || op == LessThan || op == LessThanOrEquals || op == GreaterThan
|| op == GreaterThanOrEquals) {
// Chained comparisons like ==, <, etc.
type_t *item_value_type = item_t;
ast_t *item_value = item;
if (reduction->key) {
set_binding(body_scope, op_str, item_t, compile(body_scope, item));
item_value = reduction->key;
item_value_type = get_type(body_scope, reduction->key);
}
Text_t code = Texts("({ // Reduction:\n", compile_declaration(item_value_type, Text("prev")),
";\n"
"OptionalBool_t result = NONE_BOOL;\n");
ast_t *comparison =
new (ast_t, .file = ast->file, .start = ast->start, .end = ast->end, .tag = op,
.__data.Plus.lhs = LiteralCode(Text("prev"), .type = item_value_type), .__data.Plus.rhs = item_value);
body->__data.InlineCCode.chunks = new (
ast_list_t, .ast = FakeAST(TextLiteral, Texts("if (result == NONE_BOOL) {\n"
" prev = ",
compile(body_scope, item_value),
";\n"
" result = yes;\n"
"} else {\n"
" if (",
compile(body_scope, comparison), ") {\n",
" prev = ", compile(body_scope, item_value), ";\n",
" } else {\n"
" result = no;\n",
" break;\n", " }\n", "}\n")));
code = Texts(code, compile_statement(env, loop), "\nresult;})");
return code;
} else if (op == Min || op == Max) {
// Min/max:
Text_t superlative = op == Min ? Text("min") : Text("max");
Text_t code = Texts("({ // Reduction:\n", compile_declaration(item_t, superlative),
";\n"
"Bool_t has_value = no;\n");
Text_t item_code = compile(body_scope, item);
ast_e cmp_op = op == Min ? LessThan : GreaterThan;
if (reduction->key) {
env_t *key_scope = fresh_scope(env);
set_binding(key_scope, op_str, item_t, item_code);
type_t *key_type = get_type(key_scope, reduction->key);
Text_t superlative_key = op == Min ? Text("min_key") : Text("max_key");
code = Texts(code, compile_declaration(key_type, superlative_key), ";\n");
ast_t *comparison = new (ast_t, .file = ast->file, .start = ast->start, .end = ast->end, .tag = cmp_op,
.__data.Plus.lhs = LiteralCode(Text("key"), .type = key_type),
.__data.Plus.rhs = LiteralCode(superlative_key, .type = key_type));
body->__data.InlineCCode.chunks = new (
ast_list_t, .ast = FakeAST(TextLiteral, Texts(compile_declaration(key_type, Text("key")), " = ",
compile(key_scope, reduction->key), ";\n",
"if (!has_value || ", compile(body_scope, comparison),
") {\n"
" ",
superlative, " = ", compile(body_scope, item),
";\n"
" ",
superlative_key,
" = key;\n"
" has_value = yes;\n"
"}\n")));
} else {
ast_t *comparison =
new (ast_t, .file = ast->file, .start = ast->start, .end = ast->end, .tag = cmp_op,
.__data.Plus.lhs = item, .__data.Plus.rhs = LiteralCode(superlative, .type = item_t));
body->__data.InlineCCode.chunks = new (
ast_list_t, .ast = FakeAST(TextLiteral, Texts("if (!has_value || ", compile(body_scope, comparison),
") {\n"
" ",
superlative, " = ", compile(body_scope, item),
";\n"
" has_value = yes;\n"
"}\n")));
}
code = Texts(code, compile_statement(env, loop), "\nhas_value ? ", promote_to_optional(item_t, superlative),
" : ", compile_none(item_t), ";})");
return code;
} else {
// Accumulator-style reductions like +, ++, *, etc.
type_t *reduction_type = Match(get_type(env, ast), OptionalType)->type;
ast_t *item_value = item;
if (reduction->key) {
set_binding(body_scope, op_str, item_t, compile(body_scope, item));
item_value = reduction->key;
}
Text_t code = Texts("({ // Reduction:\n", compile_declaration(reduction_type, Text("reduction")),
";\n"
"Bool_t has_value = no;\n");
// For the special case of (or)/(and), we need to early out if we
// can:
Text_t early_out = EMPTY_TEXT;
if (op == Compare) {
if (reduction_type->tag != IntType || Match(reduction_type, IntType)->bits != TYPE_IBITS32)
code_err(ast, "<> reductions are only supported for Int32 "
"values");
} else if (op == And) {
if (reduction_type->tag == BoolType) early_out = Text("if (!reduction) break;");
else if (reduction_type->tag == OptionalType)
early_out = Texts("if (", check_none(reduction_type, Text("reduction")), ") break;");
} else if (op == Or) {
if (reduction_type->tag == BoolType) early_out = Text("if (reduction) break;");
else if (reduction_type->tag == OptionalType)
early_out = Texts("if (!", check_none(reduction_type, Text("reduction")), ") break;");
}
ast_t *combination = new (ast_t, .file = ast->file, .start = ast->start, .end = ast->end, .tag = op,
.__data.Plus.lhs = LiteralCode(Text("reduction"), .type = reduction_type),
.__data.Plus.rhs = item_value);
body->__data.InlineCCode.chunks = new (
ast_list_t, .ast = FakeAST(TextLiteral, Texts("if (!has_value) {\n"
" reduction = ",
compile(body_scope, item_value),
";\n"
" has_value = yes;\n"
"} else {\n"
" reduction = ",
compile(body_scope, combination), ";\n", early_out, "}\n")));
code =
Texts(code, compile_statement(env, loop), "\nhas_value ? ",
promote_to_optional(reduction_type, Text("reduction")), " : ", compile_none(reduction_type), ";})");
return code;
}
}
|
