public static ArrayInstance From(ScriptEngine engine, ObjectInstance iterable, FunctionInstance mapFunction, object thisArg)
{
var result = new List <object>();
var iterator = TypeUtilities.GetIterator(engine, iterable);
if (iterator != null)
{
// Initialize the array from an iterator.
int index = 0;
foreach (var item in TypeUtilities.Iterate(engine, iterator))
{
object mappedValue = mapFunction?.Call(thisArg ?? Undefined.Value, item, index) ?? item;
result.Add(mappedValue);
index++;
}
}
else
{
// Initialize the array from an array-like object.
uint length = ArrayInstance.GetLength(iterable);
for (int i = 0; i < length; i++)
{
object mappedValue = mapFunction?.Call(thisArg ?? Undefined.Value, iterable[i], i) ?? iterable[i];
result.Add(mappedValue);
}
}
return(engine.Array.New(result.ToArray()));
}
/// <summary>
/// Serializes an array into a JSON string.
/// </summary>
/// <param name="value"> The array to serialize. </param>
/// <param name="result"> The StringBuilder to write the JSON representation of the
/// array to. </param>
private void SerializeArray(ObjectInstance value, StringBuilder result)
{
// Add the spacer string to the current separator string.
string previousSeparator = this.separator;
this.separator += this.Indentation;
// Check for cyclical references.
if (this.arrayStack.Contains(value) == true)
{
throw new JavaScriptException(ErrorType.TypeError, "The given object must not contain cyclical references");
}
this.arrayStack.Push(value);
result.Append('[');
uint length = ArrayInstance.GetLength(value);
for (uint i = 0; i < length; i++)
{
// Append the separator.
if (i > 0)
{
result.Append(',');
}
result.Append(this.separator);
// Transform the value using the replacer function or toJSON().
object elementValue = TransformPropertyValue(value, i);
if (elementValue == null || elementValue == Undefined.Value || elementValue is FunctionInstance || elementValue is Symbol)
{
// Undefined is serialized as "null".
result.Append("null");
}
else
{
// Serialize the element value to the output.
SerializePropertyValue(elementValue, result);
}
}
if (length > 0)
{
result.Append(previousSeparator);
}
result.Append(']');
// Remove this object from the stack.
this.arrayStack.Pop();
// Restore the separator to it's previous value.
this.separator = previousSeparator;
}
