def evaluate(self, variables):
binder = Binder(variables)
b_expr = binder.bindexpression(self.tree.root)
diag = binder.diagnostics.information
if diag: return EvaluationResult(None, diag, None)
eval = BExpressionEvaluator(b_expr, variables)
res = eval.evaluate()
return EvaluationResult(b_expr, [], res)
