In olden times, when Invocation, an experimental utility, was a part of standard library, one could invoke methods "dynamically" as shown below:
"Hello!" o 'substring(0, 4) // to get Any back
"Hello!" oo 'substring(0, 4) // for an automatic unsafe cast to expected type
How to do this with the new Scala reflection API?
Welcome to Scala version 2.10.0-20120617-072418-9a28ee1ffc (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_33).
Type in expressions to have them evaluated.
Type :help for more information.
scala> class Foo { def bar(x: Int) = x }
defined class Foo
scala> val foo = new Foo
foo @ 5935b50c: Foo = Foo@5935b50c
scala> runtimeMirror(getClass.getClassLoader).reflect(foo)
res0 @ 65c24701: reflect.runtime.universe.InstanceMirror = scala.reflect.runtime.JavaMirrors$JavaMirror$JavaInstanceMirror@65c24701
scala> res0.symbol.typeSignature.member(newTermName("bar"))
res1 @ 69624a1c: reflect.runtime.universe.Symbol = method bar
scala> res0.reflectMethod(res1.asMethodSymbol)(42)
res2 @ 4ac1d188: Any = 42
Some background information about how the API is designed can be found here: Get companion object instance with new Scala reflection API.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With