Function take_function_args

datafusion/common/src/utils/mod.rs:1053–1067

Converts a collection of function arguments into a fixed-size array of length N producing a reasonable error message in case of unexpected number of arguments. # Example ``` # use datafusion_common::Result; # use datafusion_common::utils::take_function_args; # use datafusion_common::ScalarValue; fn my_function(args: &[ScalarValue]) -> Result<()> { // function expects 2 args, so create a 2-element

(
    function_name: &str,
    args: impl IntoIterator<Item = T>,
)

/// my_function(&args).unwrap();
/// ```
pub fn take_function_args<const N: usize, T>(
    function_name: &str,
    args: impl IntoIterator<Item = T>,
) -> Result<[T; N]> {
    let args = args.into_iter().collect::<Vec<_>>();
    args.try_into().map_err(|v: Vec<T>| {
        _exec_datafusion_err!(
            "{} function requires {} {}, got {}",
            function_name,
            N,
            if N == 1 { "argument" } else { "arguments" },
            v.len()
        )
    })
}

/// Returns the inner values of a list, or an error otherwise
/// For [`ListArray`] and [`LargeListArray`], if it's sliced, it returns a