Tuples from string by regular expressions in Scala - regex

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))

Answer 2

Without regex you can do:
scala> val str = "{param1=foo}{param2=bar}hello world!"
scala> str split '}' filter(x => x.head =='{' && x.contains('=')) map{x => val Array(key, value) = x.tail split '='; key -> value }
res9: Array[(java.lang.String, java.lang.String)] = Array((param1,foo), (param2,bar))
Or in a clearer way:
// We find different blocks
val str1 = str split '}'
// We remove invalid blocks (end of the String in your case)
val str2 = str1 filter(x => x.head == '{' && x.contains('='))
// We transform the String into a tupple, removing the head
val str3 = str2 map{x =>
val Array(key, value) = x.tail split '='
key -> value
}