case语句正则表达式匹配

joe

val BookExtractorRE = """Book: title=([^,]+),\s+authors=(.+)""".r
val MagazineExtractorRE = """Magazine: title=([^,]+),\s+issue=(.+)""".r

val catalog = List(
"Book: title=Programming Scala, authors=Dean Wampler, Alex Payne",
"Magazine: title=The New Yorker, issue=January 2009",
"Book: title=War and Peace, authors=Leo Tolstoy",
"Magazine: title=The Atlantic, issue=February 2009",
"BadData: text=Who put this here??"
)

for (item <- catalog) {
item match {
  case BookExtractorRE(title, authors) =>
     println("Book \"" + title + "\", written by " + authors)
  case MagazineExtractorRE(title, issue) =>
     println("Magazine \"" + title + "\", issue " + issue)
  case entry => println("Unrecognized entry: " + entry)
}
}
显示如下：
Book "Programming Scala", written by Dean Wampler, Alex Payne
Magazine "The New Yorker", issue January 2009
Book "War and Peace", written by Leo Tolstoy
Magazine "The Atlantic", issue February 2009
Unrecognized entry: BadData: text=Who put this here??