void Visitor_DoMakeWalker::Visit_Expr_Rel_Calc(const ZRef<RelationalAlgebra::Expr_Rel_Calc>& iExpr) { if (ZRef<Walker> op0 = this->Do(iExpr->GetOp0())) this->pSetResult(new Walker_Calc(op0, iExpr->GetColName(), iExpr->GetCallable())); }