Function len_dict 

pub fn len_dict<'a, T: Integer>(
    input: CategoricalAVT<'a, T>,
) -> Result<IntegerArray<T>, KernelError>

Computes the character length of each string in a CategoricalArray<T> slice, returning an IntegerArray<T> with the same length and null semantics.

This applies to a windowed slice (offset, len) of the input categorical array, using dictionary lookup to resolve each string.

Parameters

• input: A (CategoricalArray<T>, offset, len) tuple defining the slice to operate on.

Returns

An IntegerArray<T> of the same length, with each element representing the character count of the corresponding (non-null) resolved string.