/// <summary>
/// Reduces the expression node to a simpler expression.
/// </summary>
/// <returns>The reduced expression.</returns>
public override Expression Reduce()
{
var functionalOp = new Func<Expression, Expression>(lhs =>
{
var operation = default(ExpressionType);
switch (OperationNodeType)
{
case CSharpExpressionType.PreIncrementAssign:
case CSharpExpressionType.PreIncrementAssignChecked:
case CSharpExpressionType.PostIncrementAssign:
case CSharpExpressionType.PostIncrementAssignChecked:
operation = ExpressionType.Increment;
break;
case CSharpExpressionType.PreDecrementAssign:
case CSharpExpressionType.PreDecrementAssignChecked:
case CSharpExpressionType.PostDecrementAssign:
case CSharpExpressionType.PostDecrementAssignChecked:
operation = ExpressionType.Decrement;
break;
default:
throw ContractUtils.Unreachable;
}
var args = new[]
{
CSharpArgumentInfo.Create(Operand.Flags, null)
};
var binder = Binder.UnaryOperation(Flags, operation, Context, args);
var dynamic = DynamicHelpers.MakeDynamic(typeof(object), binder, new[] { lhs }, new[] { lhs.Type });
// NB: no conversion needed in the unary case
return dynamic;
});
var flags = Flags | CSharpBinderFlags.ValueFromCompoundAssignment;
var res = DynamicHelpers.ReduceDynamicAssignment(Operand, functionalOp, flags, IsPrefix);
return res;
}
private Expression ReduceCore(DynamicCSharpArgument left)
{
var functionalOp = new Func<Expression, Expression>(lhs =>
{
var operation = default(ExpressionType);
switch (OperationNodeType)
{
case CSharpExpressionType.AddAssign:
case CSharpExpressionType.AddAssignChecked:
operation = ExpressionType.AddAssign;
break;
case CSharpExpressionType.SubtractAssign:
case CSharpExpressionType.SubtractAssignChecked:
operation = ExpressionType.SubtractAssign;
break;
case CSharpExpressionType.MultiplyAssign:
case CSharpExpressionType.MultiplyAssignChecked:
operation = ExpressionType.MultiplyAssign;
break;
case CSharpExpressionType.DivideAssign:
operation = ExpressionType.DivideAssign;
break;
case CSharpExpressionType.ModuloAssign:
operation = ExpressionType.ModuloAssign;
break;
case CSharpExpressionType.AndAssign:
operation = ExpressionType.AndAssign;
break;
case CSharpExpressionType.OrAssign:
operation = ExpressionType.OrAssign;
break;
case CSharpExpressionType.ExclusiveOrAssign:
operation = ExpressionType.ExclusiveOrAssign;
break;
case CSharpExpressionType.LeftShiftAssign:
operation = ExpressionType.LeftShiftAssign;
break;
case CSharpExpressionType.RightShiftAssign:
operation = ExpressionType.RightShiftAssign;
break;
default:
throw ContractUtils.Unreachable;
}
var args = new[]
{
CSharpArgumentInfo.Create(GetArgumentInfoFlags(Left), null),
CSharpArgumentInfo.Create(GetArgumentInfoFlags(Right), null),
};
var binder = Binder.BinaryOperation(Flags, operation, Context, args);
var dynamic = DynamicHelpers.MakeDynamic(typeof(object), binder, new[] { lhs, Right.Expression }, new[] { lhs.Type, Right.Expression.Type });
var leftType = Left.Expression.Type;
if (leftType != dynamic.Type)
{
var convert = Binder.Convert(CSharpBinderFlags.ConvertExplicit, leftType, Context);
dynamic = DynamicHelpers.MakeDynamic(leftType, convert, new[] { dynamic }, null);
}
return dynamic;
});
var flags = Flags | CSharpBinderFlags.ValueFromCompoundAssignment;
var res = DynamicHelpers.ReduceDynamicAssignment(left, functionalOp, flags);
return res;
}
private Expression WithEventCheck(GetMemberDynamicCSharpExpression member, string accessor)
{
var obj = member.Object;
var name = member.Name;
var args = member.Arguments;
Debug.Assert(args.Count == 0);
var lhs = Expression.Parameter(obj.Type, "__objTemp");
var left = Left.Update(member.Update(lhs, args));
var isEventBinder = Binder.IsEvent(CSharpBinderFlags.None, name, Context);
var isEventCheck = DynamicHelpers.MakeDynamic(typeof(bool), isEventBinder, new[] { lhs }, null);
var accessorName = accessor + name;
var accessorArgs = new[]
{
CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null),
CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null),
};
var invokeAccessorBinder = Binder.InvokeMember(CSharpBinderFlags.InvokeSpecialName | CSharpBinderFlags.ResultDiscarded, accessorName, null, Context, accessorArgs);
var invokeAccessor = DynamicHelpers.MakeDynamic(typeof(object), invokeAccessorBinder, new[] { lhs, Right.Expression }, null);
var ifNotEvent = ReduceCore(left);
var res =
Expression.Block(
new[] { lhs },
Expression.Assign(lhs, obj),
Expression.Condition(isEventCheck, invokeAccessor, ifNotEvent)
);
return res;
}
