Scala的正则表达式regex操作



9.   misc

9.1.     json

Scala-json

9.2.     Configgy

http://www.lag.net/configgy/

简单配置及logging：

----------------------------

log {

  filename = "/var/log/pingd.log"

  roll = "daily"

  level = "debug"

}

 

hostname = "pingd.example.com"

port = 3000

----------------------------

 

val conf = net.lag.configgy.Configgy.configure("/etc/pingd.conf").config

val hostname = conf.getString("hostname", "localhost")

val port = conf.getInt("port", 3000)

 

9.3.     正则表达式regex

例子1：完全匹配

//将字符串转为scala.util.matching.Regex

val pattern = "^[a-z0-9._%\\-+]+@(?:[a-z0-9\\-]+\\.)+[a-z]{2,4}$"

val emailRegex = pattern.r // 或者 new scala.util.matching.Regex(pattern)

//emailRegex.pattern=>java.util.regex.Pattern 使用java的Pattern

emailRegex.pattern.matcher("[e-mail]").matches // true

 

例子2：查找匹配部分

val p = "[0-9]+".r  

p.findAllIn("2 ad 12ab ab21 23").toList // List(2, 12, 21, 23)

p.findFirstMatchIn("abc123xyz").get // scala.util.matching.Regex.Match = 123

 

更多例子如下：

定义：

val r1 = "(\\d+) lines".r  // syntactic sugar val r2 = """(\d+) lines""".r  // using triple-quotes to preserve backslashes

或者

import scala.util.matching.Regex val r3 = new Regex("(\\d+) lines")  // standard val r4 = new Regex("""(\d+) lines""", "lines") // with named groups

 

search和replace（java.lang.String的方法）：

"99 lines" matches "(\\d+) lines" // true

"99 Lines" matches "(\\d+) lines" // false

"99 lines" replace ("99", "98") // "98 lines"

"99 lines lines" replaceAll ("l", "L") // 99 Lines Lines

 

search（regex的方法）：

"\\d+".r findFirstIn "99 lines" // Some(99)

"\\w+".r findAllIn "99 lines" // iterator(长度为2)

"\\s+".r findPrefixOf "99 lines" // None

"\\s+".r findPrefixOf "  99 lines" // Some(  )

val r4 = new Regex("""(\d+) lines""", "g1") // with named groups

r4 findFirstMatchIn "99 lines-a" // Some(99 lines)

r4 findPrefixMatchOf "99 lines-a" // Some(99 lines)

val b = (r4 findFirstMatchIn "99 lines").get.group("g1") // "99"

 

match（regex的方法）：

val r1 = "(\\d+) lines".r

val r4 = new Regex("""(\d+) lines""", "g1")

val Some(b) = r4 findPrefixOf "99 lines" // "99 lines" for {   line <- """|99 lines-a              |99 lines              |pass              |98 lines-c""".stripMargin.lines } line match {   case r1(n) => println("Has " + n + " Lines.") // "Has 99 Lines."

  case _ => }

for (matched <- "(\\w+)".r findAllIn "99 lines" matchData)

  println("Matched from " + matched.start + " to " + matched.end)

输出：

Matched from 0 to 2

Matched from 3 to 8

 

replace（regex的方法）：

val r2 = """(\d+) lines""".r  // using triple-quotes to preserve backslashes

r2 replaceFirstIn ("99 lines-a", "aaa") // "aaa-a"

r2 replaceAllIn ("99 lines-a, 98 lines-b", "bbb") // "bbb-a, bbb-b"

 

其他：使用正则表达式定义变量

val regex = "(\\d+)/(\\d+)/(\\d+)".r

val regex(year, month, day) = "2010/1/13"

// year: String = 2010

// month: String = 1

// day: String = 13

 

9.4.     GUI

9.4.1.  java方式

import javax.swing.JFrame 

var jf = new JFrame("Hello!") 

jf.setSize(800, 600) 

jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) 

jf.setVisible(true)

 

9.4.2.  scala方式

import swing._, swing.Swing._

 

object Swing1 extends SimpleGUIApplication { // scala2.7

 

  def top = new MainFrame { // 必须实现top方法

    title = "窗口1"

    preferredSize = (400, 300)

   

    val label = new Label("hello world cn中文")

    contents = new BorderPanel {

      layout(label) = BorderPanel.Position.Center

    }

  }

}