// INITIALIZATION
//_________________________________________________________________________________________
/// <summary>
/// Creates a new instance of a user-defined function.
/// </summary>
/// <param name="targetFunction"> The function that was bound. </param>
/// <param name="boundThis"> The value of the "this" parameter when the target function is called. </param>
/// <param name="boundArguments"> Zero or more bound argument values. </param>
internal BoundFunction(FunctionInstance targetFunction, object boundThis, object[] boundArguments)
: base(targetFunction.Prototype)
{
if (targetFunction == null)
{
throw new ArgumentNullException("targetFunction");
}
if (boundArguments == null)
{
boundArguments = new object[0];
}
this.TargetFunction = targetFunction;
this.BoundThis = boundThis;
this.BoundArguments = boundArguments;
// Add function properties.
this.FastSetProperty("name", targetFunction.Name, PropertyAttributes.Sealed, false);
this.FastSetProperty("length", Math.Max(targetFunction.Length - boundArguments.Length, 0), PropertyAttributes.Sealed, false);
this.FastSetProperty("prototype", this.Engine.Object.Construct(), PropertyAttributes.Writable, false);
this.InstancePrototype.FastSetProperty("constructor", this, PropertyAttributes.NonEnumerable, false);
// Caller and arguments cannot be accessed.
var thrower = new ThrowTypeErrorFunction(this.Engine.Function, "The 'caller' or 'arguments' properties cannot be accessed on a bound function.");
var accessor = new PropertyAccessorValue(thrower, thrower);
this.FastSetProperty("caller", accessor, PropertyAttributes.IsAccessorProperty, true);
this.FastSetProperty("arguments", accessor, PropertyAttributes.IsAccessorProperty, true);
}
// OBJECT SERIALIZATION AND DESERIALIZATION
//_________________________________________________________________________________________
/// <summary>
/// Creates a property descriptor from an object containing any of the following
/// properties: configurable, writable, enumerable, value, get, set.
/// </summary>
/// <param name="obj"> The object to get the property values from. </param>
/// <param name="defaults"> The values to use if the relevant value is not specified. </param>
/// <returns> A PropertyDescriptor that corresponds to the object. </returns>
public static PropertyDescriptor FromObject(ObjectInstance obj, PropertyDescriptor defaults)
{
if (obj == null)
{
return(PropertyDescriptor.Undefined);
}
// Read configurable attribute.
bool configurable = defaults.IsConfigurable;
if (obj.HasProperty("configurable"))
{
configurable = TypeConverter.ToBoolean(obj["configurable"]);
}
// Read writable attribute.
bool writable = defaults.IsWritable;
if (obj.HasProperty("writable"))
{
writable = TypeConverter.ToBoolean(obj["writable"]);
}
// Read enumerable attribute.
bool enumerable = defaults.IsEnumerable;
if (obj.HasProperty("enumerable"))
{
enumerable = TypeConverter.ToBoolean(obj["enumerable"]);
}
// Read property value.
object value = defaults.Value;
if (obj.HasProperty("value"))
{
value = obj["value"];
}
// The descriptor is an accessor if get or set is present.
bool isAccessor = false;
// Read get accessor.
FunctionInstance getter = defaults.Getter;
if (obj.HasProperty("get"))
{
if (obj.HasProperty("value"))
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptors cannot have both 'get' and 'value' set");
}
if (obj.HasProperty("writable"))
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptors with 'get' or 'set' defined must not have 'writable' set");
}
if (obj["get"] is FunctionInstance)
{
getter = (FunctionInstance)obj["get"];
}
else if (TypeUtilities.IsUndefined(obj["get"]))
{
getter = null;
}
else
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptor 'get' must be a function");
}
isAccessor = true;
}
// Read set accessor.
FunctionInstance setter = defaults.Setter;
if (obj.HasProperty("set"))
{
if (obj.HasProperty("value"))
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptors cannot have both 'set' and 'value' set");
}
if (obj.HasProperty("writable"))
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptors with 'get' or 'set' defined must not have 'writable' set");
}
if (obj["set"] is FunctionInstance)
{
setter = (FunctionInstance)obj["set"];
}
else if (TypeUtilities.IsUndefined(obj["set"]))
{
setter = null;
}
else
{
throw new JavaScriptException(obj.Engine, "TypeError", "Property descriptor 'set' must be a function");
}
isAccessor = true;
}
// Build up the attributes enum.
PropertyAttributes attributes = PropertyAttributes.Sealed;
if (configurable)
{
attributes |= PropertyAttributes.Configurable;
}
if (writable)
{
attributes |= PropertyAttributes.Writable;
}
if (enumerable)
{
attributes |= PropertyAttributes.Enumerable;
}
// Either a value or an accessor is possible.
object descriptorValue = value;
if (isAccessor)
{
descriptorValue = new PropertyAccessorValue(getter, setter);
}
// Create the new property descriptor.
return(new PropertyDescriptor(descriptorValue, attributes));
}