//Constructor
public NodeExecutor(NodeVisitor <T> visitor, NodeDiffHandler <T> handler)
: base()
{
_comparer = new NodeComparer <T>(visitor); //Default comparer - override for specifics
_verifier = new NodeVerifier <T>(_comparer); //Default verifier - override for specifics
_handler = handler;
}
//Overrides
public virtual bool Compare(T a, T b, NodeDiffHandler <T> handler)
{
//State
_handler = handler;
_a = a;
_b = b;
_same = true;
//Simple Algortyhm:
// We have a simple rountine that compares(a -> b).
// It does this through a brain-dead find routine ie: find(a in b).
//
// That would give you edits + removals, but unfortunatly doesn't give you additions in b.
// So we simply do it twice (ie: find(a, b), then find(b, a), which equates to:
// Compare(a, b) = covers:
// #1 b's removals (ie: deletions)
// #2 b's edits (ie: changes)
// Compare(b, a) = coers:
// #3 a's removals (ie: insertions)
// #4 a's edits from b (ie: changes we don't care about)
//First pass: Compare(a -> b)
_visitor.Process(a, new NodeHandler <T>(OnLeft));
//Second pass: Compare(b -> a)
_visitor.Process(b, new NodeHandler <T>(OnRight));
return(_same);
}
