/// <summary>
/// Evaluates the expression, if possible.
/// </summary>
/// <returns> The result of evaluating the expression, or <c>null</c> if the expression can
/// not be evaluated. </returns>
public override object Evaluate()
{
// Evaluate the operands.
object left = this.Left.Evaluate();
if (left == null)
{
return(null);
}
object right;
if (OperatorType == OperatorType.In)
{
right = null;
if (ResolvedPrototype == null)
{
return(null);
}
}
else
{
right = this.Right.Evaluate();
if (right == null)
{
return(null);
}
}
// Apply the binary operator logic.
switch (this.OperatorType)
{
case OperatorType.Add:
{
var leftPrimitive = TypeConverter.ToPrimitive(left, PrimitiveTypeHint.None);
var rightPrimitive = TypeConverter.ToPrimitive(right, PrimitiveTypeHint.None);
if (TypeUtilities.IsString(leftPrimitive) == true || TypeUtilities.IsString(rightPrimitive) == true)
{
return(TypeConverter.ToString(leftPrimitive) + TypeConverter.ToString(rightPrimitive));
}
return(TypeConverter.ToNumber(leftPrimitive) + TypeConverter.ToNumber(rightPrimitive));
}
// Arithmetic operations.
case OperatorType.Subtract:
return(TypeConverter.ToNumber(left) - TypeConverter.ToNumber(right));
case OperatorType.Multiply:
return(TypeConverter.ToNumber(left) * TypeConverter.ToNumber(right));
case OperatorType.Divide:
return(TypeConverter.ToNumber(left) / TypeConverter.ToNumber(right));
case OperatorType.Modulo:
return(TypeConverter.ToNumber(left) % TypeConverter.ToNumber(right));
// Bitwise operations.
case OperatorType.BitwiseAnd:
return(TypeConverter.ToInt32(left) & TypeConverter.ToInt32(right));
case OperatorType.BitwiseOr:
return(TypeConverter.ToInt32(left) | TypeConverter.ToInt32(right));
case OperatorType.BitwiseXor:
return(TypeConverter.ToInt32(left) ^ TypeConverter.ToInt32(right));
case OperatorType.LeftShift:
return(TypeConverter.ToInt32(left) << (int)(TypeConverter.ToUint32(right) & 0x1F));
case OperatorType.SignedRightShift:
return(TypeConverter.ToInt32(left) >> (int)(TypeConverter.ToUint32(right) & 0x1F));
case OperatorType.UnsignedRightShift:
return((uint)TypeConverter.ToInt32(left) >> (int)(TypeConverter.ToUint32(right) & 0x1F));
// Relational operations.
case OperatorType.LessThan:
return(TypeComparer.LessThan(left, right));
case OperatorType.LessThanOrEqual:
return(TypeComparer.LessThanOrEqual(left, right));
case OperatorType.GreaterThan:
return(TypeComparer.GreaterThan(left, right));
case OperatorType.GreaterThanOrEqual:
return(TypeComparer.GreaterThanOrEqual(left, right));
// Equality operations.
case OperatorType.Equal:
return(TypeComparer.Equals(left, right) == true);
case OperatorType.StrictlyEqual:
return(TypeComparer.StrictEquals(left, right) == true);
case OperatorType.NotEqual:
return(TypeComparer.Equals(left, right) == false);
case OperatorType.StrictlyNotEqual:
return(TypeComparer.StrictEquals(left, right) == false);
// Logical operations.
case OperatorType.LogicalAnd:
if (TypeConverter.ToBoolean(left) == false)
{
return(left);
}
return(right);
case OperatorType.LogicalOr:
if (TypeConverter.ToBoolean(left) == true)
{
return(left);
}
return(right);
// Misc
case OperatorType.In:
// Constant property! Convert it to a string:
string propertyName = TypeConverter.ToString(left);
// Exists?
return(ResolvedPrototype.GetProperty(propertyName) != null);
case OperatorType.InstanceOf:
return(null);
default:
throw new NotImplementedException(string.Format("Unsupported operator {0}", this.OperatorType));
}
}
/// <summary>
/// Generates CIL for the expression.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Literals cannot have side-effects so if a return value is not expected then generate
// nothing.
if (optimizationInfo.RootExpression == this)
{
return;
}
if (this.Value is int)
{
generator.LoadInt32((int)this.Value);
}
else if (this.Value is double)
{
generator.LoadDouble((double)this.Value);
}
else if (this.Value is string)
{
generator.LoadString((string)this.Value);
}
else if (this.Value is bool)
{
generator.LoadBoolean((bool)this.Value);
}
else if (this.Value is RegularExpressionLiteral)
{
// RegExp
var sharedRegExpVariable = optimizationInfo.GetRegExpVariable(generator, (RegularExpressionLiteral)this.Value);
var label1 = generator.CreateLabel();
var label2 = generator.CreateLabel();
// if (sharedRegExp == null) {
generator.LoadVariable(sharedRegExpVariable);
generator.LoadNull();
generator.BranchIfNotEqual(label1);
// sharedRegExp = Global.RegExp.OnConstruct(source, flags)
EmitHelpers.LoadPrototypes(generator);
generator.LoadField(ReflectionHelpers.PrototypeLookup_RegExp);
generator.LoadString(((RegularExpressionLiteral)this.Value).Pattern);
generator.LoadString(((RegularExpressionLiteral)this.Value).Flags);
generator.Call(ReflectionHelpers.RegExp_Construct);
generator.Duplicate();
generator.StoreVariable(sharedRegExpVariable);
// } else {
generator.Branch(label2);
generator.DefineLabelPosition(label1);
// Global.RegExp.OnConstruct(sharedRegExp, flags)
EmitHelpers.LoadPrototypes(generator);
generator.LoadField(ReflectionHelpers.PrototypeLookup_RegExp);
generator.LoadVariable(sharedRegExpVariable);
generator.LoadNull();
generator.Call(ReflectionHelpers.RegExp_Construct);
// }
generator.DefineLabelPosition(label2);
}
else if (this.Value == Null.Value)
{
// Null.
EmitHelpers.EmitNull(generator);
}
else if (this.Value == Undefined.Value)
{
// Undefined.
EmitHelpers.EmitUndefined(generator);
}
else if (this.Value is List <Expression> )
{
// Construct an array literal.
var arrayLiteral = (List <Expression>) this.Value;
// Operands for ArrayConstructor.New() are: an ArrayConstructor instance (ArrayConstructor), an array (object[])
// ArrayConstructor
EmitHelpers.LoadEngine(generator);
// object[]
generator.LoadInt32(arrayLiteral.Count);
generator.NewArray(typeof(object));
for (int i = 0; i < arrayLiteral.Count; i++)
{
// Operands for StoreArrayElement() are: an array (object[]), index (int), value (object).
// Array
generator.Duplicate();
// Index
generator.LoadInt32(i);
// Value
var elementExpression = arrayLiteral[i];
if (elementExpression == null)
{
generator.LoadNull();
}
else
{
elementExpression.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, elementExpression.GetResultType(optimizationInfo));
}
// Store the element value.
generator.StoreArrayElement(typeof(object));
}
// ArrayConstructor.New(object[])
generator.Call(ReflectionHelpers.Array_New);
}
else if (this.Value is List <KeyValuePair <Expression, Expression> > )
{
// This is an object literal.
var properties = (List <KeyValuePair <Expression, Expression> >) this.Value;
// We'll generate a prototype and a custom object type for it:
Library.Prototype proto = CreatedPrototype;
// Create a new object.
generator.NewObject(proto.TypeConstructor);
foreach (var keyValuePair in properties)
{
string propertyName = keyValuePair.Key.ToString();
Expression propertyValue = keyValuePair.Value;
// Duplicate the object ref:
generator.Duplicate();
// Add a new property to the object.
Type valueType = propertyValue.GetResultType(optimizationInfo);
// Get the property:
Library.PropertyVariable pv = proto.GetProperty(propertyName);
// Set it:
pv.Set(generator, optimizationInfo, false, valueType, delegate(bool two){
if (pv.IsConstant)
{
// Emit the constant:
EmitHelpers.EmitValue(generator, pv.ConstantValue);
}
else
{
// Write the value to set now:
propertyValue.GenerateCode(generator, optimizationInfo);
}
// Note: This one always ignores 'two'
});
}
}
else
{
throw new NotImplementedException("Unknown literal type.");
}
}