etorreborre

/**
 * This doesn't compile
 * type mismatch; 
 *  found   : Iterable[T] 
 *  required: CC[T] 
 *  def dropOne: CC[T] = xs.drop(1) 
 */
object o {
  implicit def extend[T, CC[T] <: Iterable[T]](xs: CC[T]) = new ExtendedIterable(xs) 
        

etorreborre

package test

import org.specs.mock.Mockito
import org.scalatest.WordSpec
import org.specs.specification._

/**
 * DefaultExampleExpectationsListener provides default behavior for specs creation of
 * examples and expectations.
 *

etorreborre

// a Map can be used as a PartialFunction
List("Darth Vador", "Eric", "Frankenstein") collect Map("Eric" -> "good", "Darth Vador" -> "very evil", "Frankenstein" -> "evil") must_== List("very evil", "good", "evil")

etorreborre

/** 
 * An answer from Jason Zaugg on the scala-internals mailing list
 * 
 *  Implicit parameters can have defaults.
 */

scala> implicit def OptionalImplicit[A <: AnyRef](implicit a: A = null) = Option(a)
OptionalImplicit: [A <: AnyRef](implicit a: A)Option[A]

scala> implicitly[Option[Ordering[Int]]]

etorreborre

/**
 * An example showing why changing a parameter to "call by name" may break clients of an API. 
 * As usual, side-effects are the main issue here,...
 */

 /** "before" api */
 def registerDatabaseState(state: DatabaseState) = // store an event with the current state of the database

 /** 
  * "after" api. Storing the event may not happen based on the configuration for example

etorreborre

[INFO] Compiling 152 source files to C:\projects\specs\specs-2.9.0\target\test-classes at 1296871592783
[INFO] java.lang.reflect.InvocationTargetException
[INFO]  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[INFO]  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[INFO]  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[INFO]  at java.lang.reflect.Method.invoke(Method.java:597)
[INFO]  at org_scala_tools_maven_executions.MainHelper.runMain(MainHelper.java:161)
[INFO]  at org_scala_tools_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)
[ERROR] Caused by: java.lang.AssertionError: assertion failed
[INFO]  at scala.Predef$.assert(Predef.scala:85)

etorreborre

"" size
1

error: scala.this.Predef.augmentString("").size of type Int does not take parameters
       "" size

etorreborre

  // a trait defining a transformation method
  trait A {
    case class Other(s: String)
    def toOther(s: String) = Other(s)
  }

  // the same trait with the method defined as implicit
  trait AB extends A {
    override implicit def toOther(s: String) = super.toOther(s)
  }

etorreborre

 // base functionality
 trait A {
    case class Other(s: String) {
      def in: String = "in"
    }
    def toOther(s: String) = Other(s)
  }
  // base functionality with an implicit
  trait AB extends A {
    override implicit def toOther(s: String) = super.toOther(s)

etorreborre

/**
 * For those examples using Around may not be very different from a simple method call with a call-by-name
 * parameter.
 * 
 * The only difference is that the http object is a named context that you can compose with other setups, like a Before setup: 
 *
 *  http://etorreborre.github.com/specs2/guide/org.specs2.guide.SpecStructure.html#Composing+contexts
 */
class AcceptanceSpec extends Specification { def is =