Combinatoric generators should accept a single integer #42
Description
Similar to utils::combn, iff a single integer is passed to icombinations or ipermutations, the iterator should return the combinations/permutations of the sequence. For example, the following should be equivalent:
icombinations(5, 2)icombinations(1:5, 2)
Currently, as.list(icombinations(5, 2)) returns list().