Escape string to be passed as regex

Question

I would like to create a function that creates regex matching an arbitrary string given at the input. For example, when I feed it with 123$ it should match lite

Answer 1

You can use Java's Pattern class to escape strings as regular expressions. See http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#quote%28java.lang.String%29

For example:

scala> Pattern.quote("123$").r.findFirstIn("123$")
res3: Option[String] = Some(123$)

Answer 2

Just to bring more attention to Harold L's comment above, if you want to do this with a Scala library you can use:

import scala.util.matching.Regex
Regex.quote("123$").r.findFirstIn("123$")