boa_ast 0.21.1

Abstract Syntax Tree definition for the Boa JavaScript engine.
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

use crate::{
    Span, Spanned,
    expression::Expression,
    visitor::{VisitWith, Visitor, VisitorMut},
};
use boa_interner::{Interner, ToInternedString};
use core::ops::ControlFlow;

/// The `conditional` (ternary) operation is the only ECMAScript operation that takes three
/// operands.
///
/// This operation takes three operands: a condition followed by a question mark (`?`),
/// then an expression to execute `if` the condition is truthy followed by a colon (`:`),
/// and finally the expression to execute if the condition is `false`.
/// This operator is frequently used as a shortcut for the `if` statement.
///
/// More information:
///  - [ECMAScript reference][spec]
///  - [MDN documentation][mdn]
///
/// [spec]: https://tc39.es/ecma262/#prod-ConditionalExpression
/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Grammar_and_types#Literals
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
#[derive(Clone, Debug, PartialEq)]
pub struct Conditional {
    condition: Box<Expression>,
    if_true: Box<Expression>,
    if_false: Box<Expression>,
}

impl Conditional {
    /// Gets the condition of the `Conditional` expression.
    #[inline]
    #[must_use]
    pub const fn condition(&self) -> &Expression {
        &self.condition
    }

    /// Gets the expression returned if `condition` is truthy.
    #[inline]
    #[must_use]
    pub const fn if_true(&self) -> &Expression {
        &self.if_true
    }

    /// Gets the expression returned if `condition` is falsy.
    #[inline]
    #[must_use]
    pub const fn if_false(&self) -> &Expression {
        &self.if_false
    }

    /// Creates a `Conditional` AST Expression.
    #[inline]
    #[must_use]
    pub fn new(condition: Expression, if_true: Expression, if_false: Expression) -> Self {
        Self {
            condition: Box::new(condition),
            if_true: Box::new(if_true),
            if_false: Box::new(if_false),
        }
    }
}

impl Spanned for Conditional {
    #[inline]
    fn span(&self) -> Span {
        Span::new(self.condition.span().start(), self.if_false.span().end())
    }
}

impl ToInternedString for Conditional {
    #[inline]
    fn to_interned_string(&self, interner: &Interner) -> String {
        format!(
            "{} ? {} : {}",
            self.condition().to_interned_string(interner),
            self.if_true().to_interned_string(interner),
            self.if_false().to_interned_string(interner)
        )
    }
}

impl From<Conditional> for Expression {
    #[inline]
    fn from(cond_op: Conditional) -> Self {
        Self::Conditional(cond_op)
    }
}

impl VisitWith for Conditional {
    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
    where
        V: Visitor<'a>,
    {
        visitor.visit_expression(&self.condition)?;
        visitor.visit_expression(&self.if_true)?;
        visitor.visit_expression(&self.if_false)
    }

    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
    where
        V: VisitorMut<'a>,
    {
        visitor.visit_expression_mut(&mut self.condition)?;
        visitor.visit_expression_mut(&mut self.if_true)?;
        visitor.visit_expression_mut(&mut self.if_false)
    }
}