Omega359 commented on code in PR #14323: URL: https://github.com/apache/datafusion/pull/14323#discussion_r1930887575
########## datafusion/functions/src/regex/regexpsubstr.rs: ########## @@ -0,0 +1,554 @@ +// 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. + +//! Regex expressions +use arrow::array::{ + Array, ArrayRef, AsArray, GenericStringArray, GenericStringBuilder, OffsetSizeTrait, +}; +use arrow::datatypes::{DataType, Int64Type}; +use arrow::error::ArrowError; +use datafusion_common::plan_err; +use datafusion_common::ScalarValue; +use datafusion_common::{ + cast::as_generic_string_array, internal_err, DataFusionError, Result, +}; +use datafusion_expr::scalar_doc_sections::DOC_SECTION_REGEX; +use datafusion_expr::{ColumnarValue, Documentation, ScalarFunctionArgs, TypeSignature}; +use datafusion_expr::{ScalarUDFImpl, Signature, Volatility}; +use regex::Regex; +use std::any::Any; +use std::sync::{Arc, OnceLock}; + +#[derive(Debug)] +pub struct RegexpSubstrFunc { + signature: Signature, +} + +impl Default for RegexpSubstrFunc { + fn default() -> Self { + Self::new() + } +} + +impl RegexpSubstrFunc { + pub fn new() -> Self { + use DataType::{Int64, LargeUtf8, Utf8}; + Self { + signature: Signature::one_of( + vec![ + // Planner attempts coercion to the target type starting with the most preferred candidate. + // For example, given input `(Utf8View, Utf8)`, it first tries coercing to `(Utf8, Utf8)`. + // If that fails, it proceeds to `(LargeUtf8, Utf8)`. + TypeSignature::Exact(vec![Utf8, Utf8]), + TypeSignature::Exact(vec![LargeUtf8, LargeUtf8]), + TypeSignature::Exact(vec![Utf8, Utf8, Int64]), + TypeSignature::Exact(vec![LargeUtf8, LargeUtf8, Int64]), + TypeSignature::Exact(vec![Utf8, Utf8, Int64, Int64]), + TypeSignature::Exact(vec![LargeUtf8, LargeUtf8, Int64, Int64]), + TypeSignature::Exact(vec![Utf8, Utf8, Int64, Int64, Utf8]), + TypeSignature::Exact(vec![ + LargeUtf8, LargeUtf8, Int64, Int64, LargeUtf8, + ]), + TypeSignature::Exact(vec![Utf8, Utf8, Int64, Int64, Utf8, Int64]), + TypeSignature::Exact(vec![ + LargeUtf8, LargeUtf8, Int64, Int64, LargeUtf8, Int64, + ]), + ], + Volatility::Immutable, + ), + } + } +} + +impl ScalarUDFImpl for RegexpSubstrFunc { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "regexp_substr" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { + Ok(arg_types[0].clone()) + } + + fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> { + let len = args + .args + .iter() + .fold(Option::<usize>::None, |acc, arg| match arg { + ColumnarValue::Scalar(_) => acc, + ColumnarValue::Array(a) => Some(a.len()), + }); + + let is_scalar = len.is_none(); + let inferred_length = len.unwrap_or(1); + let args = args + .args + .iter() + .map(|arg| arg.to_array(inferred_length)) + .collect::<Result<Vec<_>>>()?; + + let result = regexp_subst_func(&args); + if is_scalar { + // If all inputs are scalar, keeps output as scalar + let result = result.and_then(|arr| ScalarValue::try_from_array(&arr, 0)); + result.map(ColumnarValue::Scalar) + } else { + result.map(ColumnarValue::Array) + } + } + + fn documentation(&self) -> Option<&Documentation> { + Some(get_regexp_substr_doc()) + } +} + +static DOCUMENTATION: OnceLock<Documentation> = OnceLock::new(); + +fn get_regexp_substr_doc() -> &'static Documentation { Review Comment: We may want to use the new doc macro as it's been incorporated into most every udf at this point. -- 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