split a string according to repeating regular expression in Scala

Question

In Scala I have a string of the form

val str = "[ab][bc][cd][dx][42]"

What is the most efficient way in Scala, regular expression utilizing or otherwise, to split that string into a Seq[String] that would be of the form:

("ab","bc","cd","dx","42")

Thank you.

Answer 1

You can try this:

val str = "[ab][bc][cd][dx][42]"
val res = str.drop(1).sliding(2, 4).toList
println(res) // List(ab, bc, cd, dx, 42)

val str2 = "[ab]"
val res2 = str2.drop(1).sliding(2, 4).toList
println(res2) // List(ab)

val str3 = ""
val res3 = str3.drop(1).sliding(2, 4).toList
println(res3) // List()

Answer 2

you can try:

str.split("(\\]\\[)|(\\[)|(\\])").filterNot(_.isEmpty)

Mainly using groups (][, ], [) for delimiter and trimming the array.