正则匹配

Programming scala的例子

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)
      }
}

几个注意的知识点

1.“”“的符号让我们可以使用原始的字符,从而不能双斜杠

2.正则表达式里的括号是 "字符抽取"组在match匹配时可以直接绑定变量,如上面就绑定了titile,issue以及authors

（编辑：李大同）

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