/// Allows pseudo "chaining" of `$value` by sequentially invoking function calls
/// as arguments on `$value`.
/// 
/// Each argument after `$value` is a `$function-call` which can be:
/// - A single function name
/// - A list, containing the function name followed by the arguments to apply
/// to the function after the `$value` has been applied as the first argument.
/// 
/// 
/// @access public
/// @group Utility
/// @param {*} $value The initial value.
/// @param {Function...|List...} $function-calls... The function calls to apply to value.
/// @returns {*} Returns new value with "chained" function calls applied.
/// @example scss
/// $list: ('a' 'b' 'c', 'd' 'e' 'f', 'g' 'h' 'i');
/// 
/// $foo: _($list
///     _map _join,             // _map($list, _join);
///     _reduce _str-concat,    // _reduce($list, _str-concat);
///     _concat 'jkl',          // _concat($list, 'jkl');
///     _join ' -- ');          // _join($list, ' -- ');
/// // => 'abcdefghi -- jkl';

@function _($value, $function-calls...) {
    $result: $value;

    @each $function-call in $function-calls {
        $function: nth($function-call, 1);
        $args: set-nth($function-call, 1, $result);
        $result: __exec($function, $args...);
    }

    @return $result;
}