Split out arrow-string (apache#2594)

Author: tustvold

Cargo.toml

@@ -17,23 +17,24 @@
 
 [workspace]
 members = [
-        "arrow",
-        "arrow-array",
-        "arrow-buffer",
-        "arrow-cast",
-        "arrow-csv",
-        "arrow-data",
-        "arrow-flight",
-        "arrow-integration-test",
-        "arrow-integration-testing",
-        "arrow-ipc",
-        "arrow-json",
-        "arrow-schema",
-        "arrow-select",
-        "object_store",
-        "parquet",
-        "parquet_derive",
-        "parquet_derive_test",
+    "arrow",
+    "arrow-array",
+    "arrow-buffer",
+    "arrow-cast",
+    "arrow-csv",
+    "arrow-data",
+    "arrow-flight",
+    "arrow-integration-test",
+    "arrow-integration-testing",
+    "arrow-ipc",
+    "arrow-json",
+    "arrow-schema",
+    "arrow-select",
+    "arrow-string",
+    "object_store",
+    "parquet",
+    "parquet_derive",
+    "parquet_derive_test",
 ]
 # Enable the version 2 feature resolver, which avoids unifying features for targets that are not being built
 #

arrow-string/Cargo.toml

@@ -0,0 +1,49 @@
+# 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.
+
+[package]
+name = "arrow-string"
+version = "28.0.0"
+description = "String kernels for arrow arrays"
+homepage = "https://github.com/apache/arrow-rs"
+repository = "https://github.com/apache/arrow-rs"
+authors = ["Apache Arrow <[email protected]>"]
+license = "Apache-2.0"
+keywords = ["arrow"]
+include = [
+    "benches/*.rs",
+    "src/**/*.rs",
+    "Cargo.toml",
+]
+edition = "2021"
+rust-version = "1.62"
+
+[lib]
+name = "arrow_string"
+path = "src/lib.rs"
+bench = false
+
+[dependencies]
+arrow-buffer = { version = "28.0.0", path = "../arrow-buffer" }
+arrow-data = { version = "28.0.0", path = "../arrow-data" }
+arrow-schema = { version = "28.0.0", path = "../arrow-schema" }
+arrow-array = { version = "28.0.0", path = "../arrow-array" }
+regex = { version = "1.7.0", default-features = false, features = ["std", "unicode", "perf"] }
+regex-syntax = { version = "0.6.27", default-features = false, features = ["unicode"] }
+
+[features]
+dyn_cmp_dict = []

arrow/src/compute/kernels/concat_elements.rs renamed to arrow-string/src/concat_elements.rs

@@ -15,9 +15,12 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use crate::array::*;
-use crate::error::{ArrowError, Result};
+
+use arrow_array::{Array, GenericStringArray, OffsetSizeTrait};
+use arrow_array::builder::BufferBuilder;
+use arrow_data::ArrayDataBuilder;
 use arrow_data::bit_mask::combine_option_bitmap;
+use arrow_schema::ArrowError;
 
 /// Returns the elementwise concatenation of a [`StringArray`].
 ///
@@ -36,7 +39,7 @@ use arrow_data::bit_mask::combine_option_bitmap;
 pub fn concat_elements_utf8<Offset: OffsetSizeTrait>(
     left: &GenericStringArray<Offset>,
     right: &GenericStringArray<Offset>,
-) -> Result<GenericStringArray<Offset>> {
+) -> Result<GenericStringArray<Offset>, ArrowError> {
     if left.len() != right.len() {
         return Err(ArrowError::ComputeError(format!(
             "Arrays must have the same length: {} != {}",
@@ -89,7 +92,7 @@ pub fn concat_elements_utf8<Offset: OffsetSizeTrait>(
 /// An error will be returned if the [`StringArray`] are of different lengths
 pub fn concat_elements_utf8_many<Offset: OffsetSizeTrait>(
     arrays: &[&GenericStringArray<Offset>],
-) -> Result<GenericStringArray<Offset>> {
+) -> Result<GenericStringArray<Offset>, ArrowError> {
     if arrays.is_empty() {
         return Err(ArrowError::ComputeError(
             "concat requires input of at least one array".to_string(),
@@ -157,6 +160,7 @@ pub fn concat_elements_utf8_many<Offset: OffsetSizeTrait>(
 
 #[cfg(test)]
 mod tests {
+    use arrow_array::StringArray;
     use super::*;
     #[test]
     fn test_string_concat() {