/// <summary>
/// constructor
/// </summary>
/// <param name="token"></param>
/// <param name="arguments"></param>
public IfThenElse(LogicalExpression expression, IStatement @do, IStatement @else=null, Engine engine = null)
: base(engine)
{
// TODO: check the argumetns
this.NodeType = otXPTNodeType.IfThenElse;
if (@else != null)
this.Nodes = new ObservableCollection<INode>(new INode[]{expression, @do, @else});
else this.Nodes = new ObservableCollection<INode>(new INode[] { expression, @do });
}
/// <summary>
/// build a XPT Node out of a selection conditions
/// </summary>
/// <param name="ctx"></param>
/// <returns></returns>
public bool BuildXPTNode(SelectConditionsContext ctx)
{
// L_SQUARE_BRACKET R_SQUARE_BRACKET // all
if (ctx.selectCondition() == null || ctx.selectCondition().Count()==0)
{
// simple true operator
ctx.XPTreeNode = LogicalExpression.TRUE();
return true;
}
// only one condition
// selectCondition [$ClassName, $keypos]
if (ctx.selectCondition().Count() == 1)
{
if (ctx.NOT().Count() == 0) ctx.XPTreeNode = ctx.selectCondition()[0].XPTreeNode;
else ctx.XPTreeNode = LogicalExpression.NOT((IExpression)ctx.selectCondition()[0].XPTreeNode);
return true;
}
// if we have more than this
//| selectCondition [$ClassName, $keypos] (logicalOperator_2 selectCondition [$ClassName, $keypos])*
if (ctx.selectCondition().Count() > 1)
{
eXPressionTree.LogicalExpression theLogical = (LogicalExpression)ctx.selectCondition()[0].XPTreeNode;
if (theLogical == null) return false;
for(uint i = 0; i < ctx.selectCondition().Count()-1;i++)
{
Operator anOperator = ctx.logicalOperator_2()[i].Operator;
// x or y and z -> ( x or y) and z )
if (theLogical.Priority >= anOperator.Priority)
{
if ((LogicalExpression)ctx.selectCondition()[i + 1].XPTreeNode != null)
theLogical = new LogicalExpression(anOperator, theLogical, (LogicalExpression)ctx.selectCondition()[i + 1].XPTreeNode);
else return false;
// negate
if (ctx.NOT().Count() >= i+1 && ctx.NOT()[i + 1] != null)
theLogical = LogicalExpression.NOT((IExpression)theLogical);
}
else
{ // x and y or z -> x and ( y or z )
// build the new (lower) operation in the higher level tree (right with the last operand)
IExpression right = (IExpression)theLogical.RightOperand;
theLogical.RightOperand = new LogicalExpression(anOperator, right, (IExpression)ctx.selectCondition()[i + 1].XPTreeNode);
// negate
if (ctx.NOT().Count() >= i + 1 && ctx.NOT()[i + 1] != null)
theLogical.RightOperand = LogicalExpression.NOT((IExpression)theLogical.RightOperand);
}
}
ctx.XPTreeNode = theLogical;
return true;
}
return false;
}