some

    function
    boot.janet on line 2553, column 1

    (some pred x & xs)

    Returns `nil` if applying `pred` to every value in `x` results in 
    only falsey values, otherwise returns the first truthy result 
    encountered.

    Also functions variadically, i.e. takes additional arguments, with 
    suitable changes to the arity of `f`. `f` is called with both 
    values from `x` and additional arguments, and only as many times as 
    the length of the shortest of `x` and each element of `xs`. If `x` 
    or any element of `xs` is empty, returns `nil`.

    `x` and elements of `xs` can be values of type bytes, indexed, 
    dictionary, fiber, or abstract with suitable `get` and `next` 
    methods.