$ scala
Welcome to Scala version 2.10.3-20130923-e2fec6b28dfd73482945ffab85d9b582d0cb9f17 (OpenJDK 64-Bit Server VM, Java 1.7.0_79).
Type in expressions to have them evaluated.
Type :help for more information.

scala> :load /home/eje/xsvlex.scala
Loading /home/eje/xsvlex.scala...
defined module xsv

scala> xsv.test("")
res0: String = ""

scala> xsv.test("a")
res1: String = [a]

scala> xsv.test("a,b")
res2: String = [a][b]

scala> xsv.test(",")
res3: String = [][]

scala> xsv.test("a,has space")
res4: String = [a][has space]

scala> xsv.test("a,has space,has comma\\, see?")
res5: String = [a][has space][has comma, see?]

scala> xsv.test("a,has space,has comma\\, see?,'a quoted string'")
res6: String = [a][has space][has comma, see?][a quoted string]

scala> xsv.test("a,has space,has comma\\, see?,'a quoted string \\'with escaped quotes\\''")
res7: String = [a][has space][has comma, see?][a quoted string 'with escaped quotes']

scala>