retronym

trait FoldRight[-M[_]]

{
  implicit val StreamFoldRight: FoldRight[Stream] = new FoldRight[Stream] {}
  implicit val IterableFoldRight: FoldRight[Iterable] = new FoldRight[Iterable] {}

  assert(implicitly[FoldRight[Stream]] eq IterableFoldRight) // want StreamFoldRight
}

{

retronym

trait A
trait B extends A
trait C extends B

{
  trait Covariant[+X]
  type Expected = Covariant[A]
  type CandidateB = Covariant[B]
  type CandidateC = Covariant[C]
  implicitly[CandidateB <:< Expected]

retronym

// for 2.7.x compatibility
def locally[T](x: T): T = x
def implicitly[T](implicit e: T) = e

object A { 
  implicit val one = 1
}

object Test {   
  locally {

retronym

import collection.immutable.List
import java.io.{OutputStreamWriter, FileWriter, FileOutputStream, File}

import scala.io.{Source, Codec}
import scalaz._
import Scalaz._

val base = new File("""E:\code\raptor""")
val tree: Tree[Stream[File]] = base.unfoldTree[Stream[File]] {(f: File) =>
   val (files, dirs) = f.listFiles.toStream.partition(_.isFile)

retronym

import util.NameTransformer

def unfold[A](a: A, f: A => Option[A]): Stream[A] = {
  Stream.cons(a, f(a).map(unfold(_, f)).getOrElse(Stream.empty))
}

def get[T](f: java.lang.reflect.Field, a: AnyRef): T = {
  f.setAccessible(true)
  f.get(a).asInstanceOf[T]
}

retronym

import util.NameTransformer

def unfold[A](a: A, f: A => Option[A]): Stream[A] = {
  Stream.cons(a, f(a).map(unfold(_, f)).getOrElse(Stream.empty))
}

def get[T](f: java.lang.reflect.Field, a: AnyRef): T = {
  f.setAccessible(true)
  f.get(a).asInstanceOf[T]
}

retronym

> 
> compile           
[info] 
[info] == scalaz-core / compile ==
[info]   Source analysis: 118 new/modified, 0 indirectly invalidated, 0 removed.
[info] Compiling main sources...
[Classpath = merged classpath (directory classpath: /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/classes.jar
directory classpath: /System/Library/Frameworks/JavaVM.framework/Frameworks/JavaRuntimeSupport.framework/Resources/Java/JavaRuntimeSupport.jar
directory classpath: /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/ui.jar
directory classpath: /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/laf.jar

retronym

import scalaz._
import Scalaz._

val o1 = some(1)
val o2 = some(2)

val v1 = o1.<⊛>(o2, (_: Int) + (_: Int))
println(v1)

val v2 = for {

retronym

trait PartialApply1Of2[T[_, _], A] {
  type Apply[B] = T[A, B]
}

trait Foo[M[_]]

def foo[M[_]]: Foo[M] = null

// Why can't the type parameter be inferred here?
//

retronym

trait T
trait U extends U
 
implicitly[T =:= T]
// compile error
// implicitly[T =:= U]
 
def typesEqual[A, B](implicit ev: A =:= B = null) = ev ne null
assert(typesEqual[T, T] == true)
assert(typesEqual[T, U] == false)