hmmm

core/js/src/main/scala/conv.scala

@@ -0,0 +1,8 @@
+package vecxt
+
+import scala.scalajs.js.typedarray.Float64Array
+
+type vecxting = Float64Array with vecxt
+
+given Conversion[Float64Array, vecxting] with
+  def apply(in: Float64Array): vecxting = in.asInstanceOf[vecxting]

core/jvm/src/main/scala/conv.scala

@@ -0,0 +1,9 @@
+package vecxt
+
+import scala.language.implicitConversions
+
+
+type vecxting = Array[Double] with vecxt
+
+given Conversion[Array[Double], vecxting] with
+  def apply(in: Array[Double]): vecxting = in.asInstanceOf[vecxting]

core/shared/src/main/scala/vecxt/main.scala → core/jvm/src/main/scala/main.scala

@@ -1,5 +1,9 @@
-package vecxt
 
+import scala.language.implicitConversions
+
+import vecxt.given_Conversion_Array_vecxting
+
+import vecxt.*
 
 @main def checkBytecode =
   val a = Array[Double](1,2,3)

core/shared/src/main/scala/vecxt/array.extensions.scala

@@ -21,11 +21,19 @@ import vecxt.Retentions.Retention
 import scala.util.chaining.*
 import vecxt.BoundsCheck
 
-
 enum LossCalc:
   case Agg, Occ
 end LossCalc
 
+transparent trait vecxt {
+
+  def update(i: Int, d: Double): Unit
+  def apply(i:Int) : Double
+  def length: Int
+
+}
+
+
 extension (vec: Array[Boolean])
   inline def countTrue: Int =
     var sum = 0
@@ -56,7 +64,7 @@ extension (vec: Array[Boolean])
   // end copy
 end extension
 
-extension (vec: Array[Double])
+extension (vec: vecxt)
 
   def idxBoolean(index: Array[Boolean]) =
     val trues = index.countTrue
@@ -82,12 +90,12 @@ extension (vec: Array[Double])
     out
   end increments
 
-  inline def stdDev: Double =
-    // https://www.cuemath.com/data/standard-deviation/
-    val mu = vec.mean
-    val diffs_2 = vec.map(num => Math.pow(num - mu, 2))
-    Math.sqrt(diffs_2.sum / (vec.length - 1))
-  end stdDev
+  // inline def stdDev: Double =
+  //   // https://www.cuemath.com/data/standard-deviation/
+  //   val mu = vec.mean
+  //   val diffs_2 = vec.map(num => Math.pow(num - mu, 2))
+  //   Math.sqrt(diffs_2.sum / (vec.length - 1))
+  // end stdDev
 
   inline def mean: Double = vec.sum / vec.length
 
@@ -110,7 +118,7 @@ extension (vec: Array[Double])
   end cumsum
 
   inline def -(vec2: Array[Double])(using inline boundsCheck : BoundsCheck) =
-    dimCheck(vec, vec2)
+    //dimCheck(vec, vec2)
     val out = new Array[Double](vec.length)
     var i = 0
     while i < vec.length do

tests/shared/src/test/scala/arrayExtensions.test.scala

@@ -17,10 +17,14 @@
 package vecxt
 
 import scala.util.chaining.*
+import scala.language.implicitConversions
+import vecxt.given_Conversion_Array_vecxting
 
 class ArrayExtensionSuite extends munit.FunSuite:
   import vecxt.BoundsCheck.yes
 
+  //import vecxt.given_Conversion_Array_vecxting
+
   lazy val v_fill = Array.tabulate(5)(i => i.toDouble)
 
   test("Array horizontal sum") {

tests/shared/src/test/scala/boundsCheck.scala

@@ -17,6 +17,7 @@
 package vecxt
 
 import scala.util.chaining.*
+import scala.language.implicitConversions
 
 class BoundsCheckSuite extends munit.FunSuite:
 

tests/shared/src/test/scala/rpt.test.scala

@@ -18,6 +18,7 @@ package vecxt
 
 import Retentions.*
 import Limits.*
+import scala.language.implicitConversions
 
 extension [A <: AnyRef](o: A) def some = Some(o)