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Method calls & XML traversal with Scala's new Dynamic type
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class DynamicImpl(x: AnyRef) extends Dynamic { | |
def _select_(name: String): DynamicImpl = { | |
new DynamicImpl(x.getClass.getMethod(name).invoke(x)) | |
} | |
def _invoke_(name: String)(args: Any*) = { | |
new DynamicImpl(x.getClass.getMethod(name, args.map(_.asInstanceOf[AnyRef].getClass) : _*).invoke(x, args.map(_.asInstanceOf[AnyRef]) : _*)) | |
} | |
def typed[T] = x.asInstanceOf[T] | |
override def toString = "Dynamic(" + x.toString + ")" | |
} | |
implicit def toDynamic(x: Any): Dynamic = new DynamicImpl(x.asInstanceOf[AnyRef]) | |
class Duck { | |
def quack = "Quack!" | |
} | |
class QuackingSwan { | |
def quack = "Swack!" | |
} | |
def makeQuack(d: Dynamic) { | |
println(d.quack.typed[String]) | |
} | |
makeQuack(new Duck) | |
makeQuack(new QuackingSwan) | |
val s: Dynamic = "Hello, world!" | |
s.toLowerCase | |
s.toLowerCase.length | |
s.toLowerCase.length.typed[Int] |
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import scala.xml.{NodeSeq, XML} | |
class DynamicXML(n: NodeSeq) extends Dynamic { | |
def _select_(name: String) = { | |
new DynamicXML(n \ name) | |
} | |
def _invoke_(name: String)(args: Any*) = { | |
error("unsupported") | |
} | |
def typed[T] = n.asInstanceOf[T] | |
override def toString = "DynamicXML(" + n.toString + ")" | |
} | |
// A string, to prove I'm not cheating! | |
val s: String = (""" | |
<book> | |
<author> | |
<firstName>William</firstName> | |
<lastName>Shakespeare</lastName> | |
</author> | |
<title>Hamlet</title> | |
</book>""") | |
val book = new DynamicXML(XML.loadString(s)) | |
book.author.lastName | |
book.title.typed[NodeSeq].text |
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