(filter predicate list) -> list
Returns a new list containing all values in the given list that the predicate returns as true. If none are found, returns null, also known as the empty list ().
Examples:
>>(filter integer? '(1 'a "test" 3)) :: (1 3)
>>(filter port? '(1 'a "test" 3)) :: ()
Important Note: This should not be confused with define-filter and related items. This "filter" is an iterative function, so named because it comes to Mosquito Lisp from the Scheme standards.