public bool IncrementallyEquivalent(Directive other)
{
if (this.Kind != other.Kind)
{
return false;
}
bool isActive = this.IsActive;
bool otherIsActive = other.IsActive;
// states of inactive directives don't matter
if (!isActive && !otherIsActive)
{
return true;
}
if (isActive != otherIsActive)
{
return false;
}
switch (this.Kind)
{
case SyntaxKind.DefineDirectiveTrivia:
case SyntaxKind.UndefDirectiveTrivia:
return this.GetIdentifier() == other.GetIdentifier();
case SyntaxKind.IfDirectiveTrivia:
case SyntaxKind.ElifDirectiveTrivia:
case SyntaxKind.ElseDirectiveTrivia:
return this.BranchTaken == other.BranchTaken;
default:
return true;
}
}
public DirectiveStack Add(Directive directive)
{
switch (directive.Kind)
{
case SyntaxKind.EndIfDirectiveTrivia:
var prevIf = GetPreviousIf(_directives);
if (prevIf == null || !prevIf.Any())
{
goto default; // no matching if directive !! leave directive alone
}
bool tmp;
return new DirectiveStack(CompleteIf(_directives, out tmp));
case SyntaxKind.EndRegionDirectiveTrivia:
var prevRegion = GetPreviousRegion(_directives);
if (prevRegion == null || !prevRegion.Any())
{
goto default; // no matching region directive !! leave directive alone
}
return new DirectiveStack(CompleteRegion(_directives)); // remove region directives from stack but leave everything else
default:
return new DirectiveStack(new ConsList<Directive>(directive, _directives != null ? _directives : ConsList<Directive>.Empty));
}
}
