Question

I have string like {param1=foo}{param2=bar}hello world!
I need to extract array of tuples (paramName, value) from this string and get something like [(param1, foo), (param2, bar)]

Is it possible in Scala to extract this tuples by only one regex? Because I managed to do this only in way like

val str = "{param1=foo}{param2=bar}hello world!"
val param = """(?<=\{)(.+?)(?=\})""".r // extract everything between { and }
val keyValue = """(.+)=(.+)""".r // for extracting key and value
val parameters = for (keyValue(key,value) <- param.findAllIn(str).toArray) 
                     yield (key,value)

And it doesn’t look sweet.

Also I tried to use

val param = """(?<=\{)(.+?)=(.+?)(?=\})""".r

But it return param=value as one string

Answer 1

Here’s an expression that will find things like {A=B} where A and B do not contain {, }, or =.

scala> val Re = """\{([^{}=]+)=([^{}=]+)\}""".r

scala> val Re(a,b) = "{param1=foo}"
a: String = param1
b: String = foo

And if you want to find all matches in a string:

scala> val s = "{param1=foo}{param2=bar}hello world!"

scala> Re.findAllIn(s).matchData.map(_.subgroups).toList
res9: List[List[String]] = List(List(param1, foo), List(param2, bar))