adriangb commented on code in PR #19538: URL: https://github.com/apache/datafusion/pull/19538#discussion_r2721536334
########## datafusion/expr-common/src/triviality.rs: ########## @@ -0,0 +1,46 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Triviality classification for expressions and function arguments. + +/// Classification of argument triviality for scalar functions. +/// +/// This enum is used by [`ScalarUDFImpl::triviality`] to allow +/// functions to make context-dependent decisions about whether they are +/// trivial based on the nature of their arguments. +/// +/// For example, `get_field(struct_col, 'field_name')` is trivial (static field +/// lookup), but `get_field(struct_col, key_col)` is not (dynamic per-row lookup). +/// +/// [`ScalarUDFImpl::triviality`]: https://docs.rs/datafusion-expr/latest/datafusion_expr/trait.ScalarUDFImpl.html#tymethod.triviality +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub enum ArgTriviality { + /// Argument is a literal constant value or an expression that can be + /// evaluated to a constant at planning time. + Literal, Review Comment: The thing is the code cannot look at the arguments. In particular `ScalarUDFImpl` can not refer to `PhysicalExpr` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
