kazuyukitanimura commented on code in PR #513: URL: https://github.com/apache/datafusion-comet/pull/513#discussion_r1631556263
########## core/src/execution/datafusion/expressions/scalar_funcs.rs: ########## @@ -130,6 +133,10 @@ pub fn create_comet_physical_fun( let func = Arc::new(spark_xxhash64); make_comet_scalar_udf!("xxhash64", func, without data_type) } + "chr" => { Review Comment: Got it, makes sense ########## core/src/execution/datafusion/expressions/scalar_funcs/chr.rs: ########## @@ -0,0 +1,108 @@ +// 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 std::{any::Any, sync::Arc}; + +use arrow::{ + array::{ArrayRef, StringArray}, + datatypes::{ + DataType, + DataType::{Int64, Utf8}, + }, +}; + +use datafusion::logical_expr::{ColumnarValue, ScalarUDFImpl, Signature, Volatility}; +use datafusion_common::{cast::as_int64_array, exec_err, DataFusionError, Result}; + +/// chr(65) = 'A' + +// Compatible with Apache Spark's Chr function +pub fn spark_chr(args: &[ColumnarValue]) -> Result<ColumnarValue, DataFusionError> { + let chr_func = ChrFunc::default(); + chr_func.invoke(args) +} + +pub fn chr(args: &[ArrayRef]) -> Result<ArrayRef> { + let integer_array = as_int64_array(&args[0])?; + + // first map is the iterator, second is for the `Option<_>` + let result = integer_array + .iter() + .map(|integer: Option<i64>| { + integer + .map(|integer| match core::char::from_u32(integer as u32) { + Some(integer) => Ok(integer.to_string()), + None => { + exec_err!("requested character too large for encoding.") + } + }) + .transpose() + }) + .collect::<Result<StringArray>>()?; + + Ok(Arc::new(result) as ArrayRef) +} + +#[derive(Debug)] +pub struct ChrFunc { + signature: Signature, +} + +impl Default for ChrFunc { + fn default() -> Self { + Self::new() + } +} + +impl ChrFunc { + pub fn new() -> Self { + Self { + signature: Signature::uniform(1, vec![Int64], Volatility::Immutable), + } + } +} + +impl ScalarUDFImpl for ChrFunc { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "chr" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> { + Ok(Utf8) + } + + fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> { + let array = args[0].clone(); + match array { + ColumnarValue::Array(array) => { + let array = chr(&[array])?; + Ok(ColumnarValue::Array(array)) + } + _ => { + exec_err!("The first argument must be an array, but got: {:?}", array) + } Review Comment: Is handling only Array correct? It looks DataFusion is using `make_scalar_function` -- 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