datafusion_functions/string/
upper.rs

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// distributed with this work for additional information
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// 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
//
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

use crate::string::common::to_upper;
use crate::utils::utf8_to_str_type;
use arrow::datatypes::DataType;
use datafusion_common::Result;
use datafusion_expr::{ColumnarValue, Documentation};
use datafusion_expr::{ScalarUDFImpl, Signature, Volatility};
use datafusion_macros::user_doc;
use std::any::Any;

#[user_doc(
    doc_section(label = "String Functions"),
    description = "Converts a string to upper-case.",
    syntax_example = "upper(str)",
    sql_example = r#"```sql
> select upper('dataFusion');
+---------------------------+
| upper(Utf8("dataFusion")) |
+---------------------------+
| DATAFUSION                |
+---------------------------+
```"#,
    standard_argument(name = "str", prefix = "String"),
    related_udf(name = "initcap"),
    related_udf(name = "lower")
)]
#[derive(Debug)]
pub struct UpperFunc {
    signature: Signature,
}

impl Default for UpperFunc {
    fn default() -> Self {
        Self::new()
    }
}

impl UpperFunc {
    pub fn new() -> Self {
        Self {
            signature: Signature::string(1, Volatility::Immutable),
        }
    }
}

impl ScalarUDFImpl for UpperFunc {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn name(&self) -> &str {
        "upper"
    }

    fn signature(&self) -> &Signature {
        &self.signature
    }

    fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> {
        utf8_to_str_type(&arg_types[0], "upper")
    }

    fn invoke_batch(
        &self,
        args: &[ColumnarValue],
        _number_rows: usize,
    ) -> Result<ColumnarValue> {
        to_upper(args, "upper")
    }

    fn documentation(&self) -> Option<&Documentation> {
        self.doc()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use arrow::array::{Array, ArrayRef, StringArray};
    use std::sync::Arc;

    fn to_upper(input: ArrayRef, expected: ArrayRef) -> Result<()> {
        let func = UpperFunc::new();
        let batch_len = input.len();
        let args = vec![ColumnarValue::Array(input)];
        #[allow(deprecated)] // TODO migrate UDF to invoke
        let result = match func.invoke_batch(&args, batch_len)? {
            ColumnarValue::Array(result) => result,
            _ => unreachable!("upper"),
        };
        assert_eq!(&expected, &result);
        Ok(())
    }

    #[test]
    fn upper_maybe_optimization() -> Result<()> {
        let input = Arc::new(StringArray::from(vec![
            Some("农历新年"),
            None,
            Some("datafusion"),
            Some("0123456789"),
            Some(""),
        ])) as ArrayRef;

        let expected = Arc::new(StringArray::from(vec![
            Some("农历新年"),
            None,
            Some("DATAFUSION"),
            Some("0123456789"),
            Some(""),
        ])) as ArrayRef;

        to_upper(input, expected)
    }

    #[test]
    fn upper_full_optimization() -> Result<()> {
        let input = Arc::new(StringArray::from(vec![
            Some("arrow"),
            None,
            Some("datafusion"),
            Some("0123456789"),
            Some(""),
        ])) as ArrayRef;

        let expected = Arc::new(StringArray::from(vec![
            Some("ARROW"),
            None,
            Some("DATAFUSION"),
            Some("0123456789"),
            Some(""),
        ])) as ArrayRef;

        to_upper(input, expected)
    }

    #[test]
    fn upper_partial_optimization() -> Result<()> {
        let input = Arc::new(StringArray::from(vec![
            Some("arrow"),
            None,
            Some("datafusion"),
            Some("@_"),
            Some("0123456789"),
            Some(""),
            Some("\t\n"),
            Some("ὀδυσσεύς"),
            Some("tschüß"),
            Some("ⱦ"), // Ⱦ: length change
            Some("农历新年"),
        ])) as ArrayRef;

        let expected = Arc::new(StringArray::from(vec![
            Some("ARROW"),
            None,
            Some("DATAFUSION"),
            Some("@_"),
            Some("0123456789"),
            Some(""),
            Some("\t\n"),
            Some("ὈΔΥΣΣΕΎΣ"),
            Some("TSCHÜSS"),
            Some("Ⱦ"),
            Some("农历新年"),
        ])) as ArrayRef;

        to_upper(input, expected)
    }
}
datafusion_functions/string/upper.rs

datafusion_functions/string/
upper.rs
