start on int arrays.

vecxt/jvm/src/arrays.scala

@@ -23,14 +23,17 @@ import dev.ludovic.netlib.blas.JavaBLAS.getInstance as blas
 import jdk.incubator.vector.ByteVector
 import jdk.incubator.vector.DoubleVector
 import jdk.incubator.vector.VectorOperators
+import jdk.incubator.vector.IntVector
 
 object arrays:
 
+  final val spi = IntVector.SPECIES_PREFERRED
   final val spd = DoubleVector.SPECIES_PREFERRED
   final val spb = ByteVector.SPECIES_PREFERRED
 
   final val spdl = spd.length()
   final val spbl = spb.length()
+  final val spil = spi.length()
 
   extension (vec: Array[Boolean])
     inline def countTrue: Int =
@@ -89,6 +92,27 @@ object arrays:
     end ||
   end extension
 
+  extension (vec: Array[Int])
+    inline def -(vec2: Array[Int]): Array[Int] =
+      val newVec = Array.ofDim[Int](vec.length)
+      var i = 0
+
+      while i < spb.loopBound(vec.length) do
+        IntVector
+          .fromArray(spi, vec, i)
+          .sub(IntVector.fromArray(spi, vec2, i))
+          .intoArray(newVec, i)
+        i += spil
+      end while
+
+      while i < vec.length do
+        newVec(i) = vec(i) - vec2(i)
+        i += 1
+      end while
+      newVec
+
+  end extension
+
   extension (vec: Array[Double])
 
     inline def apply(index: Array[Boolean])(using inline boundsCheck: BoundsCheck) =

vecxt/test/src/intarray.test.scala

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2023 quafadas
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package vecxt
+
+import narr.*
+import scala.util.chaining.*
+import vecxt.all.*
+
+class IntArrayExtensionSuite extends munit.FunSuite:
+  import BoundsCheck.DoBoundsCheck.yes
+
+  lazy val v_fill = NArray[Double](0, 1, 2, 3, 4)
+
+  test("-") {
+    val v1 = NArray.tabulate[Int](21)(i => i)
+    val v2 = v1.drop(1) :+ (v1.last + 1)
+
+    assertVecEquals((v1 - v2), NArray.fill[Int](v1.length)(-1))
+  }
+end IntArrayExtensionSuite