Boa 0.13.1

DEPRECATED. Use the boa_engine crate instead.
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
135
136
137
138
139
140

use crate::{
    exec::Executable,
    gc::{Finalize, Trace},
    syntax::ast::{node::Node, op},
    Context, JsBigInt, JsResult, JsValue,
};
use std::fmt;

use crate::builtins::Number;
use crate::value::Numeric;
#[cfg(feature = "deser")]
use serde::{Deserialize, Serialize};

/// A unary operation is an operation with only one operand.
///
/// More information:
///  - [ECMAScript reference][spec]
///  - [MDN documentation][mdn]
///
/// [spec]: https://tc39.es/ecma262/#prod-UnaryExpression
/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Expressions_and_Operators#Unary_operators
#[cfg_attr(feature = "deser", derive(Serialize, Deserialize))]
#[derive(Clone, Debug, Trace, Finalize, PartialEq)]
pub struct UnaryOp {
    op: op::UnaryOp,
    target: Box<Node>,
}

impl UnaryOp {
    /// Creates a new `UnaryOp` AST node.
    pub(in crate::syntax) fn new<V>(op: op::UnaryOp, target: V) -> Self
    where
        V: Into<Node>,
    {
        Self {
            op,
            target: Box::new(target.into()),
        }
    }

    /// Gets the unary operation of the node.
    pub fn op(&self) -> op::UnaryOp {
        self.op
    }

    /// Gets the target of this unary operator.
    pub fn target(&self) -> &Node {
        self.target.as_ref()
    }
}

impl Executable for UnaryOp {
    fn run(&self, context: &mut Context) -> JsResult<JsValue> {
        Ok(match self.op() {
            op::UnaryOp::Minus => self.target().run(context)?.neg(context)?,
            op::UnaryOp::Plus => JsValue::new(self.target().run(context)?.to_number(context)?),
            op::UnaryOp::IncrementPost => {
                let x = self.target().run(context)?;
                let ret = x.clone();
                let result = x.to_number(context)? + 1.0;
                context.set_value(self.target(), result.into())?;
                ret
            }
            op::UnaryOp::IncrementPre => {
                let result = self.target().run(context)?.to_number(context)? + 1.0;
                context.set_value(self.target(), result.into())?
            }
            op::UnaryOp::DecrementPost => {
                let x = self.target().run(context)?;
                let ret = x.clone();
                let result = x.to_number(context)? - 1.0;
                context.set_value(self.target(), result.into())?;
                ret
            }
            op::UnaryOp::DecrementPre => {
                let result = self.target().run(context)?.to_number(context)? - 1.0;
                context.set_value(self.target(), result.into())?
            }
            op::UnaryOp::Not => self.target().run(context)?.not(context)?.into(),
            op::UnaryOp::Tilde => {
                let expr = self.target().run(context)?;
                let old_v = expr.to_numeric(context)?;
                match old_v {
                    Numeric::Number(x) => JsValue::new(Number::not(x)),
                    Numeric::BigInt(x) => JsValue::new(JsBigInt::not(&x)),
                }
            }
            op::UnaryOp::Void => {
                self.target().run(context)?;
                JsValue::undefined()
            }
            op::UnaryOp::Delete => match *self.target() {
                Node::GetConstField(ref get_const_field) => {
                    let delete_status = get_const_field
                        .obj()
                        .run(context)?
                        .to_object(context)?
                        .__delete__(&get_const_field.field().into(), context)?;

                    if !delete_status && context.strict() {
                        return context.throw_type_error("Cannot delete property");
                    } else {
                        JsValue::new(delete_status)
                    }
                }
                Node::GetField(ref get_field) => {
                    let obj = get_field.obj().run(context)?;
                    let field = &get_field.field().run(context)?;
                    let res = obj
                        .to_object(context)?
                        .__delete__(&field.to_property_key(context)?, context)?;
                    return Ok(JsValue::new(res));
                }
                Node::Identifier(_) => JsValue::new(false),
                Node::ArrayDecl(_)
                | Node::Block(_)
                | Node::Const(_)
                | Node::FunctionDecl(_)
                | Node::FunctionExpr(_)
                | Node::New(_)
                | Node::Object(_)
                | Node::UnaryOp(_) => JsValue::new(true),
                _ => return context.throw_syntax_error(format!("wrong delete argument {}", self)),
            },
            op::UnaryOp::TypeOf => JsValue::new(self.target().run(context)?.type_of()),
        })
    }
}

impl fmt::Display for UnaryOp {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}{}", self.op, self.target)
    }
}

impl From<UnaryOp> for Node {
    fn from(op: UnaryOp) -> Self {
        Self::UnaryOp(op)
    }
}