Function array_create_scalar

src/expr/src/scalar/func.rs:2518–2534

Constructs a new zero or one dimensional array out of an arbitrary number of scalars. If `datums` is empty, constructs a zero-dimensional array. Otherwise, constructs a one dimensional array whose lower bound is one and whose length is equal to `datums.len()`.

(
    datums: &[Datum<'a>],
    temp_storage: &'a RowArena,
)

/// constructs a one dimensional array whose lower bound is one and whose length
/// is equal to `datums.len()`.
fn array_create_scalar<'a>(
    datums: &[Datum<'a>],
    temp_storage: &'a RowArena,
) -> Result<Datum<'a>, EvalError> {
    let mut dims = &[ArrayDimension {
        lower_bound: 1,
        length: datums.len(),
    }][..];
    if datums.is_empty() {
        // Per PostgreSQL, empty arrays are represented with zero dimensions,
        // not one dimension of zero length. We write this condition a little
        // strangely to satisfy the borrow checker while avoiding an allocation.
        dims = &[];
    }
    let datum = temp_storage.try_make_datum(|packer| packer.try_push_array(dims, datums))?;
    Ok(datum)
}

fn stringify_datum<'a, B>(
    buf: &mut B,