boa_engine 0.21.1

Boa is a Javascript lexer, parser and compiler written in Rust. Currently, it has support for some of the language.
Documentation 
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

use crate::{
    Context, JsError, JsResult, error::JsNativeError,
    object::internal_methods::InternalMethodPropertyContext, vm::opcode::Operation,
};

use super::VaryingOperand;

/// `DeletePropertyByName` implements the Opcode Operation for `Opcode::DeletePropertyByName`
///
/// Operation:
///  - Deletes a property by name of an object
#[derive(Debug, Clone, Copy)]
pub(crate) struct DeletePropertyByName;

impl DeletePropertyByName {
    #[inline(always)]
    pub(super) fn operation(
        (object_register, index): (VaryingOperand, VaryingOperand),
        context: &mut Context,
    ) -> JsResult<()> {
        let object = context.vm.get_register(object_register.into()).clone();
        let object = object.to_object(context)?;
        let code_block = context.vm.frame().code_block();
        let key = code_block.constant_string(index.into()).into();
        let strict = code_block.strict();

        let result = object.__delete__(&key, &mut InternalMethodPropertyContext::new(context))?;
        if !result && strict {
            return Err(JsNativeError::typ()
                .with_message("Cannot delete property")
                .into());
        }
        context
            .vm
            .set_register(object_register.into(), result.into());
        Ok(())
    }
}

impl Operation for DeletePropertyByName {
    const NAME: &'static str = "DeletePropertyByName";
    const INSTRUCTION: &'static str = "INST - DeletePropertyByName";
    const COST: u8 = 3;
}

/// `DeletePropertyByValue` implements the Opcode Operation for `Opcode::DeletePropertyByValue`
///
/// Operation:
///  - Deletes a property by value of an object
#[derive(Debug, Clone, Copy)]
pub(crate) struct DeletePropertyByValue;

impl DeletePropertyByValue {
    #[inline(always)]
    pub(super) fn operation(
        (object_register, key): (VaryingOperand, VaryingOperand),
        context: &mut Context,
    ) -> JsResult<()> {
        let object = context.vm.get_register(object_register.into()).clone();
        let key = context.vm.get_register(key.into()).clone();
        let object = object.to_object(context)?;
        let property_key = key.to_property_key(context)?;

        let result = object.__delete__(
            &property_key,
            &mut InternalMethodPropertyContext::new(context),
        )?;
        if !result && context.vm.frame().code_block().strict() {
            return Err(JsNativeError::typ()
                .with_message("Cannot delete property")
                .into());
        }
        context
            .vm
            .set_register(object_register.into(), result.into());
        Ok(())
    }
}

impl Operation for DeletePropertyByValue {
    const NAME: &'static str = "DeletePropertyByValue";
    const INSTRUCTION: &'static str = "INST - DeletePropertyByValue";
    const COST: u8 = 3;
}

/// `DeleteName` implements the Opcode Operation for `Opcode::DeleteName`
///
/// Operation:
///  - Deletes a property by value of an object
#[derive(Debug, Clone, Copy)]
pub(crate) struct DeleteName;

impl DeleteName {
    #[inline(always)]
    pub(super) fn operation(
        (value, index): (VaryingOperand, VaryingOperand),
        context: &mut Context,
    ) -> JsResult<()> {
        let mut binding_locator =
            context.vm.frame().code_block.bindings[usize::from(index)].clone();
        context.find_runtime_binding(&mut binding_locator)?;
        let deleted = context.delete_binding(&binding_locator)?;
        context.vm.set_register(value.into(), deleted.into());
        Ok(())
    }
}

impl Operation for DeleteName {
    const NAME: &'static str = "DeleteName";
    const INSTRUCTION: &'static str = "INST - DeleteName";
    const COST: u8 = 3;
}

/// `DeleteSuperThrow` implements the Opcode Operation for `Opcode::DeleteSuperThrow`
///
/// Operation:
///  - Throws an error when trying to delete a property of `super`.
#[derive(Debug, Clone, Copy)]
pub(crate) struct DeleteSuperThrow;

impl DeleteSuperThrow {
    #[inline(always)]
    pub(super) fn operation((): (), _: &mut Context) -> JsError {
        JsNativeError::reference()
            .with_message("cannot delete a property of `super`")
            .into()
    }
}

impl Operation for DeleteSuperThrow {
    const NAME: &'static str = "DeleteSuperThrow";
    const INSTRUCTION: &'static str = "INST - DeleteSuperThrow";
    const COST: u8 = 2;
}