Problem Statement

A format for expressing an ordered list of integers is to use a comma separated list of either Example The list of integers: Is accurately expressed by the range expression: (And vice-versa).

Expand the range description: Note that the second element above, is the range from minus 3 to minus 1.

Let's start with the solution:

def expandRanges = { compressed ->
    Eval.me('['+compressed.replaceAll(~/(\d)-/, '$1..')+']').flatten().toString()[1..-2]
}


def s = '-6,-3--1,3-5,7-11,14,15,17-20'
println (expandRanges(s))