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use super::{JsBigInt, JsObject, JsResult, JsValue, PreferredType};
use crate::{Context, JsVariant, builtins::Number};
use std::collections::HashSet;
impl JsValue {
/// Inner loop of the deep equality comparison, strict.
pub(crate) fn deep_strict_equals_inner(
&self,
other: &Self,
encounters: &mut HashSet<usize>,
context: &mut Context,
) -> JsResult<bool> {
match (self.as_object(), other.as_object()) {
(None, None) => Ok(self.strict_equals(other)),
(Some(x), Some(y)) => JsObject::deep_strict_equals_inner(&x, &y, encounters, context),
_ => Ok(false),
}
}
/// Deep strict equality.
///
/// If the value is an object/array, also compare the key-values.
/// It uses `strict_equals()` for non-object values.
pub fn deep_strict_equals(&self, other: &Self, context: &mut Context) -> JsResult<bool> {
self.deep_strict_equals_inner(other, &mut HashSet::new(), context)
}
/// Strict equality comparison.
///
/// This method is executed when doing strict equality comparisons with the `===` operator.
/// For more information, check <https://tc39.es/ecma262/#sec-strict-equality-comparison>.
#[must_use]
pub fn strict_equals(&self, other: &Self) -> bool {
// 1. If Type(x) is different from Type(y), return false.
if self.get_type() != other.get_type() {
return false;
}
match (self.variant(), other.variant()) {
// 2. If Type(x) is Number or BigInt, then
// a. Return ! Type(x)::equal(x, y).
(JsVariant::BigInt(x), JsVariant::BigInt(y)) => JsBigInt::equal(&x, &y),
(JsVariant::Float64(x), JsVariant::Float64(y)) => Number::equal(x, y),
(JsVariant::Float64(x), JsVariant::Integer32(y)) => Number::equal(x, f64::from(y)),
(JsVariant::Integer32(x), JsVariant::Float64(y)) => Number::equal(f64::from(x), y),
(JsVariant::Integer32(x), JsVariant::Integer32(y)) => x == y,
//Null has to be handled specially because "typeof null" returns object and if we managed
//this without a special case we would compare self and other as if they were actually
//objects which unfortunately fails
//Specification Link: https://tc39.es/ecma262/#sec-typeof-operator
(JsVariant::Null, JsVariant::Null) => true,
// 3. Return ! SameValueNonNumeric(x, y).
(_, _) => Self::same_value_non_numeric(self, other),
}
}
/// Abstract equality comparison.
///
/// This method is executed when doing abstract equality comparisons with the `==` operator.
/// For more information, check <https://tc39.es/ecma262/#sec-abstract-equality-comparison>
#[allow(clippy::float_cmp)]
pub fn equals(&self, other: &Self, context: &mut Context) -> JsResult<bool> {
// 1. If Type(x) is the same as Type(y), then
// a. Return the result of performing Strict Equality Comparison x === y.
if self.get_type() == other.get_type() {
return Ok(self.strict_equals(other));
}
Ok(match (self.variant(), other.variant()) {
// 2. If x is null and y is undefined, return true.
// 3. If x is undefined and y is null, return true.
(JsVariant::Null, JsVariant::Undefined) | (JsVariant::Undefined, JsVariant::Null) => {
true
}
// 3. If Type(x) is Number and Type(y) is String, return the result of the comparison x == ! ToNumber(y).
// 4. If Type(x) is String and Type(y) is Number, return the result of the comparison ! ToNumber(x) == y.
//
// https://github.com/rust-lang/rust/issues/54883
(
JsVariant::Integer32(_) | JsVariant::Float64(_),
JsVariant::String(_) | JsVariant::Boolean(_),
)
| (JsVariant::String(_), JsVariant::Integer32(_) | JsVariant::Float64(_)) => {
let x = self.to_number(context)?;
let y = other.to_number(context)?;
Number::equal(x, y)
}
// 6. If Type(x) is BigInt and Type(y) is String, then
// a. Let n be ! StringToBigInt(y).
// b. If n is NaN, return false.
// c. Return the result of the comparison x == n.
(JsVariant::BigInt(a), JsVariant::String(b)) => JsBigInt::from_js_string(&b) == Some(a),
// 7. If Type(x) is String and Type(y) is BigInt, return the result of the comparison y == x.
(JsVariant::String(a), JsVariant::BigInt(b)) => JsBigInt::from_js_string(&a) == Some(b),
// 8. If Type(x) is Boolean, return the result of the comparison ! ToNumber(x) == y.
(JsVariant::Boolean(x), _) => {
return other.equals(&JsValue::new(i32::from(x)), context);
}
// 9. If Type(y) is Boolean, return the result of the comparison x == ! ToNumber(y).
(_, JsVariant::Boolean(y)) => return self.equals(&JsValue::new(i32::from(y)), context),
// 10. If Type(x) is either String, Number, BigInt, or Symbol and Type(y) is Object, return the result
// of the comparison x == ? ToPrimitive(y).
(
JsVariant::Object(_),
JsVariant::String(_)
| JsVariant::Float64(_)
| JsVariant::Integer32(_)
| JsVariant::BigInt(_)
| JsVariant::Symbol(_),
) => {
let primitive = self.to_primitive(context, PreferredType::Default)?;
return Ok(primitive
.equals(other, context)
.expect("should not fail according to spec"));
}
// 11. If Type(x) is Object and Type(y) is either String, Number, BigInt, or Symbol, return the result
// of the comparison ? ToPrimitive(x) == y.
(
JsVariant::String(_)
| JsVariant::Float64(_)
| JsVariant::Integer32(_)
| JsVariant::BigInt(_)
| JsVariant::Symbol(_),
JsVariant::Object(_),
) => {
let primitive = other.to_primitive(context, PreferredType::Default)?;
return Ok(primitive
.equals(self, context)
.expect("should not fail according to spec"));
}
// 12. If Type(x) is BigInt and Type(y) is Number, or if Type(x) is Number and Type(y) is BigInt, then
// a. If x or y are any of NaN, +∞, or -∞, return false.
// b. If the mathematical value of x is equal to the mathematical value of y, return true; otherwise return false.
(JsVariant::BigInt(a), JsVariant::Float64(b)) => a == b,
(JsVariant::Float64(a), JsVariant::BigInt(b)) => a == b,
(JsVariant::BigInt(a), JsVariant::Integer32(b)) => a == b,
(JsVariant::Integer32(a), JsVariant::BigInt(b)) => a == b,
// 13. Return false.
_ => false,
})
}
/// The internal comparison abstract operation SameValue(x, y),
/// where x and y are ECMAScript language values, produces true or false.
///
/// More information:
/// - [ECMAScript][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-samevalue
#[must_use]
pub fn same_value(x: &Self, y: &Self) -> bool {
// 1. If Type(x) is different from Type(y), return false.
if x.get_type() != y.get_type() {
return false;
}
match (x.variant(), y.variant()) {
// 2. If Type(x) is Number or BigInt, then
// a. Return ! Type(x)::SameValue(x, y).
(JsVariant::BigInt(x), JsVariant::BigInt(y)) => JsBigInt::same_value(&x, &y),
(JsVariant::Float64(x), JsVariant::Float64(y)) => Number::same_value(x, y),
(JsVariant::Float64(x), JsVariant::Integer32(y)) => Number::same_value(x, f64::from(y)),
(JsVariant::Integer32(x), JsVariant::Float64(y)) => Number::same_value(f64::from(x), y),
(JsVariant::Integer32(x), JsVariant::Integer32(y)) => x == y,
// 3. Return ! SameValueNonNumeric(x, y).
(_, _) => Self::same_value_non_numeric(x, y),
}
}
/// The internal comparison abstract operation `SameValueZero(x, y)`,
/// where `x` and `y` are ECMAScript language values, produces `true` or `false`.
///
/// `SameValueZero` differs from `SameValue` only in its treatment of `+0` and `-0`.
///
/// More information:
/// - [ECMAScript][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-samevaluezero
#[must_use]
pub fn same_value_zero(x: &Self, y: &Self) -> bool {
if x.get_type() != y.get_type() {
return false;
}
match (x.variant(), y.variant()) {
// 2. If Type(x) is Number or BigInt, then
// a. Return ! Type(x)::SameValueZero(x, y).
(JsVariant::BigInt(x), JsVariant::BigInt(y)) => JsBigInt::same_value_zero(&x, &y),
(JsVariant::Float64(x), JsVariant::Float64(y)) => Number::same_value_zero(x, y),
(JsVariant::Float64(x), JsVariant::Integer32(y)) => {
Number::same_value_zero(x, f64::from(y))
}
(JsVariant::Integer32(x), JsVariant::Float64(y)) => {
Number::same_value_zero(f64::from(x), y)
}
(JsVariant::Integer32(x), JsVariant::Integer32(y)) => x == y,
// 3. Return ! SameValueNonNumeric(x, y).
(_, _) => Self::same_value_non_numeric(x, y),
}
}
fn same_value_non_numeric(x: &Self, y: &Self) -> bool {
debug_assert!(x.get_type() == y.get_type());
match (x.variant(), y.variant()) {
(JsVariant::Null, JsVariant::Null) | (JsVariant::Undefined, JsVariant::Undefined) => {
true
}
(JsVariant::String(x), JsVariant::String(y)) => x == y,
(JsVariant::Boolean(x), JsVariant::Boolean(y)) => x == y,
(JsVariant::Object(x), JsVariant::Object(y)) => JsObject::equals(&x, &y),
(JsVariant::Symbol(x), JsVariant::Symbol(y)) => x == y,
_ => false,
}
}
}