@Emigna @Mr.Xcoder Another question if you don't mind. Let's say we have a ranged list [1,2,3,4,5,6,7,8] and a second (uniquified) list [2,5,7], and now we want to have a result of [[1,2],[2,3,4,5],[5,6,7],[7,8]], what would be the shortest to accomplish that? (NOTE: If the individual numbers are present more than once it doesn't matter, later on they are mapped to first/last as pair anyway.

I now use Ÿ€ÐεN3%iI˜yåið]#, which results in [[1,1,1,2],[2,3,3,3,4,4,4,5],[5,6,6,6,7],[7,8,8,8]], but it seems extremely long to accomplish this..

Never mind, been able to golf it to ŸεI˜yåiðy)]˜#. But if you guys see anything more to golf, let me know. :)