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use arrow::array::{ArrayRef, UInt32Array, Utf8Array};
use arrow::buffer::Buffer;
use arrow::datatypes::DataType;
use std::sync::Arc;

pub fn string_lengths(array: &Utf8Array<i64>) -> ArrayRef {
    let values = array.offsets().windows(2).map(|x| (x[1] - x[0]) as u32);

    let values = Buffer::from_trusted_len_iter(values);

    let array = UInt32Array::from_data(DataType::UInt32, values, array.validity().cloned());
    Arc::new(array)
}