alamb commented on code in PR #10879: URL: https://github.com/apache/datafusion/pull/10879#discussion_r1636789004
########## datafusion/functions/src/string/contains.rs: ########## @@ -0,0 +1,143 @@ +// 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. + +use crate::utils::make_scalar_function; +use arrow::array::{ArrayRef, OffsetSizeTrait}; +use arrow::datatypes::DataType; +use arrow::datatypes::DataType::Boolean; +use datafusion_common::cast::as_generic_string_array; +use datafusion_common::DataFusionError; +use datafusion_common::Result; +use datafusion_common::{arrow_datafusion_err, exec_err}; +use datafusion_expr::ScalarUDFImpl; +use datafusion_expr::TypeSignature::Exact; +use datafusion_expr::{ColumnarValue, Signature, Volatility}; +use std::any::Any; +use std::sync::Arc; +#[derive(Debug)] +pub struct ContainsFunc { + signature: Signature, +} + +impl Default for ContainsFunc { + fn default() -> Self { + ContainsFunc::new() + } +} + +impl ContainsFunc { + pub fn new() -> Self { + use DataType::*; + Self { + signature: Signature::one_of( + vec![Exact(vec![Utf8, Utf8]), Exact(vec![LargeUtf8, LargeUtf8])], + Volatility::Immutable, + ), + } + } +} + +impl ScalarUDFImpl for ContainsFunc { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "contains" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, _: &[DataType]) -> Result<DataType> { + Ok(Boolean) + } + + fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> { + match args[0].data_type() { + DataType::Utf8 => make_scalar_function(contains::<i32>, vec![])(args), + DataType::LargeUtf8 => make_scalar_function(contains::<i64>, vec![])(args), + other => { + exec_err!("unsupported data type {other:?} for function contains") + } + } + } +} + +/// use regexp_is_match_utf8_scalar to do the calculation for contains Review Comment: What are the semantics of substring supposed to be? If the idea is that contains only looks for a substring, perhaps instead of implementing `invoke()` directly, we could implement https://docs.rs/datafusion/latest/datafusion/logical_expr/struct.ScalarUDF.html#method.simplify and rewrite from `contains(x, y)` to `x LIKE '%y%` (aka rewrite to `Expr::Like` which is already pretty well optimized I tink ########## datafusion/functions/src/string/mod.rs: ########## @@ -149,6 +149,9 @@ pub mod expr_fn { ),( uuid, "returns uuid v4 as a string value", + ), ( + contains, + "Return true if search_string is found within string.", Review Comment: I think we should also mention here that search_string is treated like a regex ########## datafusion/functions/src/string/mod.rs: ########## @@ -149,6 +149,9 @@ pub mod expr_fn { ),( uuid, "returns uuid v4 as a string value", + ), ( + contains, + "Return true if search_string is found within string.", Review Comment: I think we should also mention here that search_string is treated like a regex if that is the intention -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
