generics - Abstracting Common Behavior with Traits in Scala -

i have trait following:

trait mytrait[t] {   def dosomething(elems: seq[t]) } 

i have factory create instances of implementations of trait:

object mytrait {   def apply(): mytrait = {     new stringtrait()   } } 

now concrete implementation looks this:

class stringtrait extends mytrait[string] {   def dosomething(elems: seq[string]) = {     // generic logic here     // specific logic here (this code bit depends on type of implementation)     // generic logic here    } } 

how make stringtrait such pass in specific behavior , having generic logic defined in abstract class? 1 way pass in behavior thunk, wold mean have modify dosomething(...) method take additional parameter prefer avoid.

you have few options, sake of illustration i'll assume type specific behaviour seq[t] => t (i.e. take sequence of t , produce t result):

inheritance based:

trait mytrait[t] {   def dotypespecificstuff(a: seq[t]): t    def dosomething(elems: seq[t]): t = {     // generic code stuff     val t: t = dotypespecificstuff(elems)     // more generic code     t   } }  class stringtrait extends mytrait[string] {   def dotypespecificstuff(elems: seq[string]) = {     elems.reduceoption(_ + _).getorelse("")   } }  def client(thing: mytrait[string], elems: seq[string]) {   thing.dosomething(elems) } 

type class:

trait mytypeclass[t] {   def dotypespecificstuff(a: seq[t]): t }  object stringtypeclass {   implicit val instance: stringtypeclass = new stringtypeclass() }  class stringtypeclass extends mytypeclass[string] {   def dotypespecificstuff(elems: seq[string]): string = {     elems.reduceoption(_ + _).getorelse("")   } }  object typeclassdependentbehaviour {   def dosomething[t](elems: seq[t])(implicit tp: mytypeclass[t]): t ={     //some code     val stuff: t = tp.dotypespecificstuff(elems)     //more generic code     stuff   } }  def client(elems: seq[string]) {   typeclassdependentbehaviour.dosomething(elems) }