Why is the matching behavior different for the same matcher?
val str = "project git commit: da2837ec0a" val Expr = "([a-f0-9]{10})$".r scala> str match { case Pattern(c) => c; case _ => "no match" } res30: String = no match scala> (Pattern findFirstIn str).get res31: String = da2837ec0a When you use regular expressions with pattern matching, you must match the entire string. If this behaviour is not desired, you can make it an unanchored regular expression thus: val Pattern = "whatever".r.unanchored
In contrast, findFirstIn looks for a match anywhere within the string – and so doesn't require unanchored for this to match in your example.
This is documented in the API reference which is often helpful for questions like these.
