gtani7

scala> trait Foo { type Bar }
defined trait Foo

scala> def withFoo(foo: Foo): foo.Bar = // The return type depends on the parameter!
     |   sys.error("Not yet implemented")
withFoo: (foo: Foo)foo.Bar

gtani7

scala> def f[A[_] <: Seq[_]](f: A[Int]) = f.head
f: [A[_] <: Seq[_]](f: A[Int])A

scala> def f[A[_] <: Seq[t] forSome { type t }](f: A[Int]) = f.head
f: [A[_] <: Seq[_]](f: A[Int])A

scala> def f[A[t] <: Seq[_] forSome { type t}](f: A[Int]) = f.head
f: [A[t] <: Seq[_] forSome { type t }](f: A[Int])A

gtani7

{-# LANGUAGE OverloadedStrings, BangPatterns #-}
import qualified Data.Sequence as S
import qualified Data.Foldable as F
import Control.Monad
import Data.Hashable
import Data.Sequence ((|>), ViewL(..))
import Data.Function (on)
import qualified Data.ByteString.Char8 as B
import qualified Data.HashTable.IO as H
import Data.List