houqp commented on a change in pull request #1006: URL: https://github.com/apache/arrow-datafusion/pull/1006#discussion_r727711685
########## File path: datafusion/src/physical_plan/expressions/get_indexed_field.rs ########## @@ -0,0 +1,111 @@ +// 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. + +//! get field of a struct array + +use std::{any::Any, sync::Arc}; + +use arrow::{ + datatypes::{DataType, Schema}, + record_batch::RecordBatch, +}; + +use crate::arrow::array::Array; +use crate::arrow::compute::concat; +use crate::scalar::ScalarValue; +use crate::{ + error::DataFusionError, + error::Result, + field_util::get_indexed_field as get_data_type_field, + physical_plan::{ColumnarValue, PhysicalExpr}, +}; +use arrow::array::ListArray; +use std::fmt::Debug; + +/// expression to get a field of a struct array. +#[derive(Debug)] +pub struct GetIndexedFieldExpr { + arg: Arc<dyn PhysicalExpr>, + key: ScalarValue, +} + +impl GetIndexedFieldExpr { + /// Create new get field expression + pub fn new(arg: Arc<dyn PhysicalExpr>, key: ScalarValue) -> Self { + Self { arg, key } + } + + /// Get the input expression + pub fn arg(&self) -> &Arc<dyn PhysicalExpr> { + &self.arg + } +} + +impl std::fmt::Display for GetIndexedFieldExpr { + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { + write!(f, "({}).[{}]", self.arg, self.key) + } +} + +impl PhysicalExpr for GetIndexedFieldExpr { + fn as_any(&self) -> &dyn Any { + self + } + + fn data_type(&self, input_schema: &Schema) -> Result<DataType> { + let data_type = self.arg.data_type(input_schema)?; + get_data_type_field(&data_type, &self.key).map(|f| f.data_type().clone()) + } + + fn nullable(&self, input_schema: &Schema) -> Result<bool> { + let data_type = self.arg.data_type(input_schema)?; + get_data_type_field(&data_type, &self.key).map(|f| f.is_nullable()) + } + + fn evaluate(&self, batch: &RecordBatch) -> Result<ColumnarValue> { + let arg = self.arg.evaluate(batch)?; + match arg { + ColumnarValue::Array(array) => match (array.data_type(), &self.key) { + (DataType::List(_), ScalarValue::Int64(Some(i))) => { + let as_list_array = + array.as_any().downcast_ref::<ListArray>().unwrap(); + let x: Vec<Arc<dyn Array>> = as_list_array + .iter() + .filter_map(|o| o.map(|list| list.slice(*i as usize, 1))) + .collect(); + let vec = x.iter().map(|a| a.as_ref()).collect::<Vec<&dyn Array>>(); + let iter = concat(vec.as_slice()).unwrap(); + Ok(ColumnarValue::Array(iter)) + } + _ => Err(DataFusionError::NotImplemented( + "get indexed field is only possible on lists".to_string(), + )), + }, + ColumnarValue::Scalar(_) => Err(DataFusionError::NotImplemented( + "field is not yet implemented for scalar values".to_string(), + )), + } + } +} + +/// Create a `.[field]` expression +pub fn get_indexed_field( + arg: Arc<dyn PhysicalExpr>, + key: ScalarValue, +) -> Result<Arc<dyn PhysicalExpr>> { + Ok(Arc::new(GetIndexedFieldExpr::new(arg, key))) Review comment: Good call, the result wrapping is not needed here. ########## File path: datafusion/src/physical_plan/expressions/get_indexed_field.rs ########## @@ -0,0 +1,111 @@ +// 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. + +//! get field of a struct array + +use std::{any::Any, sync::Arc}; + +use arrow::{ + datatypes::{DataType, Schema}, + record_batch::RecordBatch, +}; + +use crate::arrow::array::Array; +use crate::arrow::compute::concat; +use crate::scalar::ScalarValue; +use crate::{ + error::DataFusionError, + error::Result, + field_util::get_indexed_field as get_data_type_field, + physical_plan::{ColumnarValue, PhysicalExpr}, +}; +use arrow::array::ListArray; +use std::fmt::Debug; + +/// expression to get a field of a struct array. +#[derive(Debug)] +pub struct GetIndexedFieldExpr { + arg: Arc<dyn PhysicalExpr>, + key: ScalarValue, +} + +impl GetIndexedFieldExpr { + /// Create new get field expression + pub fn new(arg: Arc<dyn PhysicalExpr>, key: ScalarValue) -> Self { + Self { arg, key } + } + + /// Get the input expression + pub fn arg(&self) -> &Arc<dyn PhysicalExpr> { + &self.arg + } +} + +impl std::fmt::Display for GetIndexedFieldExpr { + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { + write!(f, "({}).[{}]", self.arg, self.key) + } +} + +impl PhysicalExpr for GetIndexedFieldExpr { + fn as_any(&self) -> &dyn Any { + self + } + + fn data_type(&self, input_schema: &Schema) -> Result<DataType> { + let data_type = self.arg.data_type(input_schema)?; + get_data_type_field(&data_type, &self.key).map(|f| f.data_type().clone()) + } + + fn nullable(&self, input_schema: &Schema) -> Result<bool> { + let data_type = self.arg.data_type(input_schema)?; + get_data_type_field(&data_type, &self.key).map(|f| f.is_nullable()) + } + + fn evaluate(&self, batch: &RecordBatch) -> Result<ColumnarValue> { + let arg = self.arg.evaluate(batch)?; + match arg { + ColumnarValue::Array(array) => match (array.data_type(), &self.key) { + (DataType::List(_), ScalarValue::Int64(Some(i))) => { + let as_list_array = + array.as_any().downcast_ref::<ListArray>().unwrap(); + let x: Vec<Arc<dyn Array>> = as_list_array + .iter() + .filter_map(|o| o.map(|list| list.slice(*i as usize, 1))) + .collect(); + let vec = x.iter().map(|a| a.as_ref()).collect::<Vec<&dyn Array>>(); + let iter = concat(vec.as_slice()).unwrap(); + Ok(ColumnarValue::Array(iter)) + } + _ => Err(DataFusionError::NotImplemented( + "get indexed field is only possible on lists".to_string(), + )), + }, + ColumnarValue::Scalar(_) => Err(DataFusionError::NotImplemented( + "field is not yet implemented for scalar values".to_string(), + )), + } + } +} + +/// Create a `.[field]` expression +pub fn get_indexed_field( + arg: Arc<dyn PhysicalExpr>, + key: ScalarValue, +) -> Result<Arc<dyn PhysicalExpr>> { + Ok(Arc::new(GetIndexedFieldExpr::new(arg, key))) Review comment: perhaps this whole helper function is not needed, `Arc::new(GetIndexedFieldExpr::new(arg, key))` is quite readable to me. -- This is an automated message from the Apache Git Service. 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