Scala collections have an inverse of isEmpty, called nonEmpty.
On Oct 11, 2013 11:39 AM, "cvogt" <notifications@github.com> wrote:

> In src/main/scala/scala/slick/collection/heterogenous/HList.scala:
>
> > +  type Length = Fold[Nat, ({ type L[X <: HList, Z <: Nat] = Succ[Z] })#L, Nat._0]
> > +  /** The type of prepending an element of type E to this HList */
> > +  type :: [E] = HCons[E, Self]
> > +  /** The type of concatenating another HList with this HList */
> > +  type ::: [L <: HList] = L#Fold[HList, ({ type L[X <: HList, Z <: HList] = Z # :: [X#Head] })#L, Self]
> > +
> > +  /** Get the first element, or throw a NoSuchElementException if this HList is empty. */
> > +  def head: Head
> > +  /** Get the tail of the list, or throw a NoSuchElementException if this HList is empty. */
> > +  def tail: Tail
> > +  /** Return this HList typed as `Self`/ */
> > +  def self: Self
> > +  /** Fold the elements of this HList. */
> > +  def fold[U, F[_ <: HList, _ <: U] <: U, Z <: U](f: TypedFunction2[HList, U, U, F], z: Z): Fold[U, F, Z]
> > +  /** Check if this HList is non-empty. */
> > +  def isDefined: Boolean
>
> The name of this method does not really make sense for collections. Scala
> collections only have isEmpty, not isDefined (which only exists in Optionand
> Position). I would propose we remove this method in favor of isEmpty.
>
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> .
>