sepBy package:turtle

p sepBy sep matches zero or more occurrences of p separated by sep

>>> match (decimal `sepBy` char ',') "1,2,3"
[[1,2,3]]

>>> match (decimal `sepBy` char ',') ""
[[]]

p sepBy1 sep matches one or more occurrences of p separated by sep

>>> match (decimal `sepBy1` ",") "1,2,3"
[[1,2,3]]

>>> match (decimal `sepBy1` ",") ""
[]