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[scala] vector math parameterized class in scala

by Jonathan Bachrach-2 :: Rate this Message:

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i'm trying to define a vector math class using parameterized classes in scala and am having trouble.  here's an abbreviated version of what i wrote:

class Vec3[T <: Number] (xa: T, ya: T, za: T) {
  val x: T = xa; val y: T = ya; val z: T = za
  def + (o: Vec3[T]): Vec3[T] = new Vec3(x + o.x, y + o.y, z + o.z) 
  def * (s: T): Vec3[T] = new Vec3(x * s, y * s, z * s) 
  def len (): T = x + y + z 
  def == (o: Vec3[T]): Boolean = x == o.x && y == o.y && z == o.z 
  def < (o: Vec3[T]): Boolean = x < o.x && y < o.y && z < o.z 
}

and here's what scalac says:

rala-692> scalac vec3.scala
vec3.scala:3: error: type mismatch;
 found   : T
 required: String
  def + (o: Vec3[T]): Vec3[T] = new Vec3(x + o.x, y + o.y, z + o.z) 
                                               ^
vec3.scala:3: error: type mismatch;
 found   : T
 required: String
  def + (o: Vec3[T]): Vec3[T] = new Vec3(x + o.x, y + o.y, z + o.z) 
                                                        ^
vec3.scala:3: error: type mismatch;
 found   : T
 required: String
  def + (o: Vec3[T]): Vec3[T] = new Vec3(x + o.x, y + o.y, z + o.z) 
                                                                 ^
vec3.scala:4: error: value * is not a member of T
  def * (s: T): Vec3[T] = new Vec3(x * s, y * s, z * s) 
                                     ^
vec3.scala:4: error: value * is not a member of T
  def * (s: T): Vec3[T] = new Vec3(x * s, y * s, z * s) 
                                            ^
vec3.scala:4: error: value * is not a member of T
  def * (s: T): Vec3[T] = new Vec3(x * s, y * s, z * s) 
                                                   ^
vec3.scala:5: error: type mismatch;
 found   : T
 required: String
  def len (): T = x + y + z 
                      ^
vec3.scala:7: error: value < is not a member of T
  def < (o: Vec3[T]): Boolean = x < o.x && y < o.y && z < o.z 
                                  ^
8 errors found

i had added the T <: Number to try to make it so that the + would be compatible but it still thinks + only works with strings.  i'm not even completely sure that Number is a real Scala Class.  i'm obviously not understanding how to write parameterized classes in scala.  any help would be appreciated.

 « Return to Thread: [scala] vector math parameterized class in scala

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