protected override void Initialize(EvaluationContext context)
{
_canBuildFast = true;
var expression = (ObjectExpression)_expression;
if (expression.Properties.Count == 0)
{
// empty object initializer
return;
}
var engine = context.Engine;
_valueExpressions = new JintExpression[expression.Properties.Count];
_properties = new ObjectProperty[expression.Properties.Count];
for (var i = 0; i < _properties.Length; i++)
{
string?propName = null;
var property = expression.Properties[i];
if (property is Property p)
{
if (p.Key is Literal literal)
{
propName = EsprimaExtensions.LiteralKeyToString(literal);
}
if (!p.Computed && p.Key is Identifier identifier)
{
propName = identifier.Name;
_canBuildFast &= propName != "__proto__";
}
_properties[i] = new ObjectProperty(propName, p);
if (p.Kind == PropertyKind.Init || p.Kind == PropertyKind.Data)
{
var propertyValue = p.Value;
_valueExpressions[i] = Build(engine, propertyValue);
_canBuildFast &= !propertyValue.IsFunctionDefinition();
}
else
{
_canBuildFast = false;
}
}
else if (property is SpreadElement spreadElement)
{
_canBuildFast = false;
_properties[i] = null;
_valueExpressions[i] = Build(engine, spreadElement.Argument);
}
else
{
ExceptionHelper.ThrowArgumentOutOfRangeException("property", "cannot handle property " + property);
}
_canBuildFast &= propName != null;
}
}
/// <summary>
/// A version of <see cref="EsprimaExtensions.GetKey"/> that cannot get into loop as we are already building a stack.
/// </summary>
private static string GetPropertyKey(Expression expression)
{
if (expression is Literal literal)
{
return(EsprimaExtensions.LiteralKeyToString(literal));
}
if (expression is Identifier identifier)
{
return(identifier.Name);
}
if (expression is StaticMemberExpression staticMemberExpression)
{
return(GetPropertyKey(staticMemberExpression.Object) + "." + GetPropertyKey(staticMemberExpression.Property));
}
return("?");
}
public override string ToString()
{
return(EsprimaExtensions.DoubleToString(_value));
}
