public SymPreProcessorWorkerElseIf(SymParserWorkerContext aContext)
: base(aContext)
{
// When the else token is reached, we must work back up the tree
// looking for the previous (i.e. most recent) conditional expression
// node.
SymNodeConditionalExpression condExpNode = SymParserWorkerConditionalExpression.FindMostRecentConditionalExpression(aContext.Document.CurrentNode);
if (condExpNode == null)
{
throw new Exception("Unable to locate most recent condition expression during ELSE IF handling");
}
// There must always be a positive condition node and some kind of condition
if (condExpNode.ChildTypeExists(typeof(SymNodeCondition)) == false)
{
throw new Exception("No child condition node found during ELSE IF handling");
}
// Make the conditional expression the current node
aContext.Document.CurrentNode = condExpNode;
// Make a new condition worker. The condition worker creates a new condition node
// which becomes the new current node.
SymParserWorkerContext context = new SymParserWorkerContext(aContext.Document.Context, this);
SymParserWorkerCondition conditionWorker = new SymParserWorkerCondition(context, new SymNodePreProcessorCondition(aContext.CurrentToken.Value));
AddChild(conditionWorker);
}
public SymPreProcessorWorkerEndif(SymParserWorkerContext aContext)
: base(aContext)
{
// When the endif token is reached, we must work back up the tree
// looking for the previous (i.e. most recent) conditional expression
// node.
SymNodeConditionalExpression condExpNode = SymParserWorkerConditionalExpression.FindMostRecentConditionalExpression(aContext.Document.CurrentNode);
if (condExpNode == null)
{
throw new Exception("Unable to locate most recent condition expression during ENDIF handling");
}
// There must always be a positive condition node and some kind of condition
if (condExpNode.ChildTypeExists(typeof(SymNodeCondition)) == false)
{
throw new Exception("No child condition node found during ENDIF handling");
}
// We change the current node to be the parent of the conditional expression.
// Any new tokens will appear as siblings
aContext.Document.CurrentNode = condExpNode.Parent;
// Make sure we tell the parser that it can pop off this conditional expression node.
SymPreProcessorParser parser = (SymPreProcessorParser)aContext.Parser;
SymNodeConditionalExpression poppedExpression = parser.ConditionalExpressionPop();
System.Diagnostics.Debug.Assert(poppedExpression == condExpNode);
// Job done - dequeue
RemoveSelf();
}
public SymNodeConditionalExpression ConditionalExpressionPop()
{
System.Diagnostics.Debug.Assert(iCondExpResultStack.Count > 0);
//
SymNodeConditionalExpression top = ConditionalExpressionPeek();
iCondExpResultStack.Pop();
return(top);
}
public SymParserWorkerConditionalExpression(SymParserWorkerContext aContext)
: base(aContext)
{
SymNode node = new SymNodeConditionalExpression(aContext.CurrentToken);
aContext.Document.CurrentNode.Add(node);
// Make this child node the new parent
aContext.Document.CurrentNode = node;
}
public SymNodeConditionalExpression ConditionalExpressionPeek()
{
SymNodeConditionalExpression top = null;
//
if (iCondExpResultStack.Count > 0)
{
top = (SymNodeConditionalExpression)iCondExpResultStack.Peek();
}
//
return(top);
}
public void ConditionalExpressionPush(SymNodeConditionalExpression aConditionalExpression)
{
bool inheritedValue = true;
//
SymNodeConditionalExpression top = ConditionalExpressionPeek();
if (top != null)
{
inheritedValue = top.InheritedValue;
}
//
aConditionalExpression.InheritedValue = inheritedValue;
iCondExpResultStack.Push(aConditionalExpression);
}
protected override void HandleTerminatingConditionMatch(SymToken aToken)
{
// Give the condition node ownership of the raw parsed tokens
iConditionNode.AssignArgumentTokens(iTokenBalancer.DocumentTree);
// We only need to evaluate the conditional arguments if we have not yet
// found a positive branch.
SymNodeConditionalExpression condExpNode = (SymNodeConditionalExpression)iConditionNode.Parent;
if (condExpNode.HasPositiveBranch == false)
{
iConditionNode.Evaluate(WorkerContext);
}
// We remain as the current node, even after we die. This allows
// the body of the condition to be added as our child.
}
public static SymNodeConditionalExpression FindMostRecentConditionalExpression(SymNode aCurrentNode)
{
SymNodeConditionalExpression ret = null;
//
SymNodeEnumeratorUpTreeSiblingsFirst iterator = new SymNodeEnumeratorUpTreeSiblingsFirst(aCurrentNode);
//
foreach (SymNode node in iterator)
{
if (node is SymNodeConditionalExpression)
{
ret = (SymNodeConditionalExpression)node;
break;
}
}
//
return(ret);
}
