private VariableName findPreviousValidScope(ExecutedBlock scopeBlock, Instance instance)
{
//find variable with valid scope
var block = View.PreviousBlock(scopeBlock);
var scopeEnds = new HashSet <VariableName>();
ExecutedBlock firstScopeEnd = null;
while (block != null)
{
scopeEnds.UnionWith(block.ScopeEnds(instance));
foreach (var start in block.ScopeStarts(instance))
{
if (!scopeEnds.Contains(start))
{
//we have found variable with valid scope
return(start);
}
}
if (firstScopeEnd == null && scopeEnds.Count > 0)
{
//if there is no valid variable scope with wanted instance,
//then we can try to shift first scope end founded
firstScopeEnd = block;
}
//shift to next block
block = View.PreviousBlock(block);
}
if (firstScopeEnd != null)
{
if (ShiftBehindTransformation.Shift(firstScopeEnd, scopeBlock, View))
{
//scope end was shifted
return(firstScopeEnd.ScopeEnds(instance).First());
}
}
return(null);
}
/// <summary>
/// Get scope ends of instance for given block in current view.
/// </summary>
/// <param name="block">The block.</param>
/// <param name="instance">Instance which scope ends are requested.</param>
/// <returns>Enumeration of variables which scope ends at given block.</returns>
internal IEnumerable <VariableName> ScopeEnds(ExecutedBlock block, Instance instance)
{
return(block.ScopeEnds(instance));
}
