fernandomora

import scala.language.higherKinds

def sequence[A, M[X] <: TraversableOnce[X]](in: M[Monad[A]])(implicit cbf: CanBuildFrom[M[Monad[A]], A, M[A]]): Monad[M[A]] = {
  val unit = Monad(cbf(in))
  in.foldLeft(unit){
    (mba, ma) => for (ba <- mba; a <- ma) yield ba += a
  }.map(_.result())
}

fernandomora

def square[Element, IT[_] <: Iterable[Element], That](it: IT[Element])
          (implicit bf: CanBuildFrom[IT[Element], Element, That],
           num: Numeric[Element]): That = {
  val b = bf.apply(it)
  b.sizeHint(it)
  it.foreach(elem => b += num.times(elem,elem) )
  b.result()
}

fernandomora

\setenv LESS '-iMSx4FXRe'
\pset pager always
\pset null ¤
\pset linestyle unicode
\pset border 2

-- Returns query time cost with each order
\timing

-- Returns more information on errors