e/Loopless algorithm

Information
has gloss	eng: In computational combinatorics, a loopless algorithm or loopless imperative algorithm is an imperative algorithm that generates successive combinatorial objects, such as partitions, permutations, and combinations, in constant time and the first object in linear time. The objects must be immediately available in simple form without requiring any additional steps. The standard function unfoldr is a right-associative Bird unfold.<ref name="bird06"/>
lexicalization	eng: Loopless algorithm
instance of	c/Combinatorial algorithms