internal term Canonicalize(term term)
{
switch (term.Kind)
{
case TermKind.Atom: return(term);
case TermKind.Apply: return(term.Apply(Canonicalize(term.ApplyF), Canonicalize(term.ApplyX)));
case TermKind.Var:
atom existing;
if (_canonicalName.TryGetValue(term.VarName, out existing))
{
return(term.Var(existing));
}
return(term.Var(_canonicalName[term.VarName] = new atom("var_" + (++_counter))));
}
throw new Exception("unreachable path");
}
private term Unfree(term term)
{
switch (term.Kind)
{
case TermKind.Atom: return(term);
case TermKind.Apply: return(term.Apply(Unfree(term.ApplyF), Unfree(term.ApplyX)));
case TermKind.Var: return(Generate(term.VarName, (a, x, y) => term.Var(new atom(a.Value + "_" + x)))); // TODO: This should be a utility op in atom
}
throw new Exception("unreachable case");
}