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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
use crate::{
builtins::value::Value,
environment::{
environment_record_trait::EnvironmentRecordTrait,
lexical_environment::{Environment, EnvironmentType},
},
};
use gc::{Finalize, Trace};
use rustc_hash::FxHashMap;
#[derive(Trace, Finalize, Debug, Clone)]
pub struct DeclarativeEnvironmentRecordBinding {
pub value: Option<Value>,
pub can_delete: bool,
pub mutable: bool,
pub strict: bool,
}
#[derive(Debug, Trace, Finalize, Clone)]
pub struct DeclarativeEnvironmentRecord {
pub env_rec: FxHashMap<String, DeclarativeEnvironmentRecordBinding>,
pub outer_env: Option<Environment>,
}
impl EnvironmentRecordTrait for DeclarativeEnvironmentRecord {
fn has_binding(&self, name: &str) -> bool {
self.env_rec.contains_key(name)
}
fn create_mutable_binding(&mut self, name: String, deletion: bool) {
if self.env_rec.contains_key(&name) {
panic!("Identifier {} has already been declared", name);
}
self.env_rec.insert(
name,
DeclarativeEnvironmentRecordBinding {
value: None,
can_delete: deletion,
mutable: true,
strict: false,
},
);
}
fn create_immutable_binding(&mut self, name: String, strict: bool) -> bool {
if self.env_rec.contains_key(&name) {
panic!("Identifier {} has already been declared", name);
}
self.env_rec.insert(
name,
DeclarativeEnvironmentRecordBinding {
value: None,
can_delete: true,
mutable: false,
strict,
},
);
true
}
fn initialize_binding(&mut self, name: &str, value: Value) {
if let Some(ref mut record) = self.env_rec.get_mut(name) {
if record.value.is_none() {
record.value = Some(value);
} else {
panic!("Identifier {} has already been defined", name);
}
}
}
#[allow(clippy::else_if_without_else)]
fn set_mutable_binding(&mut self, name: &str, value: Value, mut strict: bool) {
if self.env_rec.get(name).is_none() {
if strict {
panic!("Reference Error: Cannot set mutable binding for {}", name);
}
self.create_mutable_binding(name.to_owned(), true);
self.initialize_binding(name, value);
return;
}
let record: &mut DeclarativeEnvironmentRecordBinding = self.env_rec.get_mut(name).unwrap();
if record.strict {
strict = true
}
if record.value.is_none() {
panic!("Reference Error: Cannot set mutable binding for {}", name);
}
if record.mutable {
record.value = Some(value);
} else if strict {
panic!("TypeError: Cannot mutate an immutable binding {}", name);
}
}
fn get_binding_value(&self, name: &str, _strict: bool) -> Value {
if let Some(binding) = self.env_rec.get(name) {
binding
.value
.as_ref()
.expect("Could not get record as reference")
.clone()
} else {
panic!("ReferenceError: Cannot get binding value for {}", name);
}
}
fn delete_binding(&mut self, name: &str) -> bool {
match self.env_rec.get(name) {
Some(binding) => {
if binding.can_delete {
self.env_rec.remove(name);
true
} else {
false
}
}
None => false,
}
}
fn has_this_binding(&self) -> bool {
false
}
fn get_this_binding(&self) -> Value {
Value::undefined()
}
fn has_super_binding(&self) -> bool {
false
}
fn with_base_object(&self) -> Value {
Value::undefined()
}
fn get_outer_environment(&self) -> Option<Environment> {
self.outer_env.as_ref().cloned()
}
fn set_outer_environment(&mut self, env: Environment) {
self.outer_env = Some(env);
}
fn get_environment_type(&self) -> EnvironmentType {
EnvironmentType::Declarative
}
fn get_global_object(&self) -> Option<Value> {
match &self.outer_env {
Some(outer) => outer.borrow().get_global_object(),
None => None,
}
}
}