Function regexp_instr

datafusion/functions/src/regex/regexpinstr.rs:203–282

`arrow-rs` style implementation of `regexp_instr` function. This function `regexp_instr` is responsible for returning the index of a regular expression pattern within a string array. It supports optional start positions and flags for case insensitivity. The function accepts a variable number of arguments: - `values`: The array of strings to search within. - `regex_array`: The array of regular exp

(
    values: &dyn Array,
    regex_array: &dyn Datum,
    start_array: Option<&dyn Datum>,
    nth_array: Option<&dyn Datum>,
    flags_array: Option<&dyn Datum>,
    subexpr_array: Option<&dyn Datum

/// # Errors
/// Returns an error if the input arrays have mismatched lengths or if the regular expression fails to compile.
fn regexp_instr(
    values: &dyn Array,
    regex_array: &dyn Datum,
    start_array: Option<&dyn Datum>,
    nth_array: Option<&dyn Datum>,
    flags_array: Option<&dyn Datum>,
    subexpr_array: Option<&dyn Datum>,
) -> Result<ArrayRef, ArrowError> {
    let (regex_array, _) = regex_array.get();
    let start_array = start_array.map(|start| {
        let (start, _) = start.get();
        start
    });
    let nth_array = nth_array.map(|nth| {
        let (nth, _) = nth.get();
        nth
    });
    let flags_array = flags_array.map(|flags| {
        let (flags, _) = flags.get();
        flags
    });
    let subexpr_array = subexpr_array.map(|subexpr| {
        let (subexpr, _) = subexpr.get();
        subexpr
    });

    match (values.data_type(), regex_array.data_type(), flags_array) {
        (Utf8, Utf8, None) => regexp_instr_inner(
            &values.as_string::<i32>(),
            &regex_array.as_string::<i32>(),
            start_array.map(|start| start.as_primitive::<Int64Type>()),
            nth_array.map(|nth| nth.as_primitive::<Int64Type>()),
            None,
            subexpr_array.map(|subexpr| subexpr.as_primitive::<Int64Type>()),
        ),
        (Utf8, Utf8, Some(flags_array)) if *flags_array.data_type() == Utf8 => regexp_instr_inner(
            &values.as_string::<i32>(),
            &regex_array.as_string::<i32>(),
            start_array.map(|start| start.as_primitive::<Int64Type>()),
            nth_array.map(|nth| nth.as_primitive::<Int64Type>()),
            Some(flags_array.as_string::<i32>()),
            subexpr_array.map(|subexpr| subexpr.as_primitive::<Int64Type>()),
        ),
        (LargeUtf8, LargeUtf8, None) => regexp_instr_inner(
            &values.as_string::<i64>(),
            &regex_array.as_string::<i64>(),
            start_array.map(|start| start.as_primitive::<Int64Type>()),
            nth_array.map(|nth| nth.as_primitive::<Int64Type>()),
            None,
            subexpr_array.map(|subexpr| subexpr.as_primitive::<Int64Type>()),
        ),
        (LargeUtf8, LargeUtf8, Some(flags_array)) if *flags_array.data_type() == LargeUtf8 => regexp_instr_inner(
            &values.as_string::<i64>(),
            &regex_array.as_string::<i64>(),
            start_array.map(|start| start.as_primitive::<Int64Type>()),
            nth_array.map(|nth| nth.as_primitive::<Int64Type>()),
            Some(flags_array.as_string::<i64>()),
            subexpr_array.map(|subexpr| subexpr.as_primitive::<Int64Type>()),