findepi commented on code in PR #14470: URL: https://github.com/apache/datafusion/pull/14470#discussion_r1977038476
########## datafusion/functions-nested/src/max.rs: ########## @@ -0,0 +1,137 @@ +// 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. + +//! [`ScalarUDFImpl`] definitions for array_max function. +use crate::utils::make_scalar_function; +use arrow::array::ArrayRef; +use arrow::datatypes::DataType; +use arrow::datatypes::DataType::{LargeList, List}; +use datafusion_common::cast::as_list_array; +use datafusion_common::utils::take_function_args; +use datafusion_common::{exec_err, ScalarValue}; +use datafusion_doc::Documentation; +use datafusion_expr::{ColumnarValue, ScalarUDFImpl, Signature, Volatility}; +use datafusion_functions_aggregate::min_max; +use datafusion_macros::user_doc; +use itertools::Itertools; +use std::any::Any; + +make_udf_expr_and_func!( + ArrayMax, + array_max, + array, + "returns the maximum value in the array.", + array_max_udf +); + +#[user_doc( + doc_section(label = "Array Functions"), + description = "Returns the maximum value in the array.", + syntax_example = "array_max(array)", + sql_example = r#"```sql +> select array_max([3,1,4,2]); ++-----------------------------------------+ +| array_max(List([3,1,4,2])) | ++-----------------------------------------+ +| 4 | ++-----------------------------------------+ +```"#, + argument( + name = "array", + description = "Array expression. Can be a constant, column, or function, and any combination of array operators." + ) +)] +#[derive(Debug)] +pub struct ArrayMax { + signature: Signature, + aliases: Vec<String>, +} + +impl Default for ArrayMax { + fn default() -> Self { + Self::new() + } +} + +impl ArrayMax { + pub fn new() -> Self { + Self { + signature: Signature::array(Volatility::Immutable), + aliases: vec!["list_max".to_string()], + } + } +} + +impl ScalarUDFImpl for ArrayMax { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "array_max" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> datafusion_common::Result<DataType> { + match &arg_types[0] { + List(field) | LargeList(field) => Ok(field.data_type().clone()), + _ => exec_err!("Not reachable, data_type should be List or LargeList"), + } + } + + fn invoke_batch( + &self, + args: &[ColumnarValue], + _number_rows: usize, + ) -> datafusion_common::Result<ColumnarValue> { + make_scalar_function(array_max_inner)(args) + } + + fn aliases(&self) -> &[String] { + &self.aliases + } + + fn documentation(&self) -> Option<&Documentation> { + self.doc() + } +} + +/// array_max SQL function +/// +/// There is one argument for array_max as the array. +/// `array_max(array)` +/// +/// For example: +/// > array_max(\[1, 3, 2]) -> 3 +pub fn array_max_inner(args: &[ArrayRef]) -> datafusion_common::Result<ArrayRef> { + let [arg1] = take_function_args("array_max", args)?; + + match arg1.data_type() { + List(_) | LargeList(_) => { + let input_list_array = as_list_array(&arg1)?; Review Comment: as_list_array works for List type, doesn't work for LargeList type is there test coverage for LargeList ? -- 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
