check shapes in arithmetic operations

fixes #59

multik-api/src/main/kotlin/org/jetbrains/kotlinx/multik/ndarray/data/Internals.kt

@@ -30,6 +30,11 @@ internal inline fun requireArraySizes(rightSize: Int, otherSize: Int) {
     require(rightSize == otherSize) { "Array sizes don't match: (right operand size) $rightSize != $otherSize (left operand size)" }
 }
 
+@Suppress("NOTHING_TO_INLINE")
+internal inline fun requireEqualShape(left: IntArray, right: IntArray) {
+    require(left.contentEquals(right)) { "Array shapes don't match: ${left.contentToString()} != ${right.contentToString()}" }
+}
+
 @Suppress("NOTHING_TO_INLINE")
 internal inline fun requirePositiveShape(dim: Int) {
     require(dim > 0) { "Shape must be positive but was $dim." }

multik-api/src/main/kotlin/org/jetbrains/kotlinx/multik/ndarray/operations/IteratingNDArray.kt

@@ -25,7 +25,7 @@ public fun <T, D : Dimension> MultiArray<T, D>.isTransposed(): Boolean {
 
 // TODO: boolean array
 public infix fun <T : Number, D : Dimension> MultiArray<T, D>.and(other: MultiArray<T, D>): NDArray<Int, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
 
     val ret = mk.zeros<Int, D>(this.shape, DataType.IntDataType)
     val lIter = this.iterator()
@@ -61,7 +61,7 @@ public infix fun <T : Number, D : Dimension> MultiArray<T, D>.and(other: MultiAr
 }
 
 public infix fun <T : Number, D : Dimension> MultiArray<T, D>.or(other: MultiArray<T, D>): NDArray<Int, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
 
     val ret = mk.zeros<Int, D>(this.shape, DataType.IntDataType)
     val lIter = this.iterator()
@@ -796,7 +796,7 @@ public inline fun <T, D : Dimension, reified R : Any> MultiArray<T, D>.map(trans
  * Returns the element-wise minimum of array elements for [this] and [other].
  */
 public fun <T: Number, D : Dimension> MultiArray<T, D>.minimum(other: MultiArray<T, D>): NDArray<T, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     val ret = (this as NDArray).deepCopy()
     when (dtype) {
             DataType.DoubleDataType -> (ret as NDArray<Double, D>).commonAssignOp(other.iterator() as Iterator<Double>) { a, b -> min(a, b) }

multik-api/src/main/kotlin/org/jetbrains/kotlinx/multik/ndarray/operations/_ArithmeticNDArray.kt

@@ -24,7 +24,7 @@ public operator fun <T, D : Dimension> MultiArray<T, D>.unaryMinus(): NDArray<T,
  * Create a new array as the sum of [this] and [other].
  */
 public operator fun <T, D : Dimension> MultiArray<T, D>.plus(other: MultiArray<T, D>): NDArray<T, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     val ret = if (this.consistent) (this as NDArray).copy() else (this as NDArray).deepCopy()
     ret += other
     return ret
@@ -40,7 +40,7 @@ public operator fun <T, D : Dimension> MultiArray<T, D>.plus(other: T): NDArray<
  * Add [other] to [this]. Inplace operator.
  */
 public operator fun <T, D : Dimension> MutableMultiArray<T, D>.plusAssign(other: MultiArray<T, D>) {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     if (this.consistent && other.consistent) {
         this.data += (other.data as MemoryView)
     } else {
@@ -82,7 +82,7 @@ public operator fun <T, D : Dimension> MutableMultiArray<T, D>.plusAssign(other:
  * Create a new array as difference between [this] and [other].
  */
 public operator fun <T, D : Dimension> MultiArray<T, D>.minus(other: MultiArray<T, D>): NDArray<T, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     val ret = if (this.consistent) (this as NDArray).copy() else (this as NDArray).deepCopy()
     ret -= other
     return ret
@@ -98,7 +98,7 @@ public operator fun <T, D : Dimension> MultiArray<T, D>.minus(other: T): NDArray
  * Subtract [other] from [this]. Inplace operator.
  */
 public operator fun <T, D : Dimension> MutableMultiArray<T, D>.minusAssign(other: MultiArray<T, D>) {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     if (this.consistent && other.consistent) {
         this.data -= (other.data as MemoryView)
     } else {
@@ -139,7 +139,7 @@ public operator fun <T, D : Dimension> MutableMultiArray<T, D>.minusAssign(other
  * Create a new array as product of [this] and [other].
  */
 public operator fun <T, D : Dimension> MultiArray<T, D>.times(other: MultiArray<T, D>): NDArray<T, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     val ret = if (this.consistent) (this as NDArray).copy() else (this as NDArray).deepCopy()
     ret *= other
     return ret
@@ -155,7 +155,7 @@ public operator fun <T, D : Dimension> MultiArray<T, D>.times(other: T): NDArray
  * Multiply [this] by [other]. Inplace operator.
  */
 public operator fun <T, D : Dimension> MutableMultiArray<T, D>.timesAssign(other: MultiArray<T, D>) {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     if (this.consistent && other.consistent) {
         this.data *= (other.data as MemoryView)
     } else {
@@ -196,7 +196,7 @@ public operator fun <T, D : Dimension> MutableMultiArray<T, D>.timesAssign(other
  * Create a new array as division of [this] by [other].
  */
 public operator fun <T, D : Dimension> MultiArray<T, D>.div(other: MultiArray<T, D>): NDArray<T, D> {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     val ret = if (this.consistent) (this as NDArray).copy() else (this as NDArray).deepCopy()
     ret /= other
     return ret
@@ -212,7 +212,7 @@ public operator fun <T, D : Dimension> MultiArray<T, D>.div(other: T): NDArray<T
  * Divide [this] by [other]. Inplace operator.
  */
 public operator fun <T, D : Dimension> MutableMultiArray<T, D>.divAssign(other: MultiArray<T, D>) {
-    requireArraySizes(this.size, other.size)
+    requireEqualShape(this.shape, other.shape)
     if (this.consistent && other.consistent) {
         this.data /= (other.data as MemoryView)
     } else {

multik-api/src/test/kotlin/org/jetbrains/kotlinx/multik/ndarray/data/InternalsTest.kt

@@ -0,0 +1,48 @@
+package org.jetbrains.kotlinx.multik.ndarray.data
+
+import org.jetbrains.kotlinx.multik.api.empty
+import org.jetbrains.kotlinx.multik.api.mk
+import org.jetbrains.kotlinx.multik.api.zeros
+import kotlin.test.Test
+import kotlin.test.assertTrue
+import kotlin.test.fail
+
+class InternalsTest {
+
+    @Test
+    fun `require equal shape throws exception for unequal shape`() {
+        val left = mk.zeros<Double>(0, 1, 2, 3)
+        val right = mk.zeros<Double>(0, 1, 2, 4)
+        expectUnEqualShape(left, right)
+    }
+
+    @Test
+    fun `require equal shape throws exception for different no of dim`() {
+        val left = mk.zeros<Double>(0, 1, 2, 3)
+        val right = mk.zeros<Double>(0, 1, 2)
+        expectUnEqualShape(left, right)
+    }
+
+    @Test
+    fun `require equal shape succeeds for arrays with equal shapes`() {
+        val left = mk.zeros<Double>(0, 1, 2, 3)
+        val right = mk.zeros<Double>(0, 1, 2, 3)
+        requireEqualShape(left.shape, right.shape)
+    }
+
+    @Test
+    fun `require equal shape succeeds empty arrays`() {
+        val left = mk.zeros<Double>(0)
+        val right = mk.zeros<Double>(0)
+        assertTrue(left.isEmpty())
+        assertTrue(right.isEmpty())
+        requireEqualShape(left.shape, right.shape)
+    }
+
+    private fun expectUnEqualShape(left: NDArray<Double, *>, right: NDArray<Double, *>) {
+        try {
+            requireEqualShape(left.shape, right.shape)
+            fail("Exception expected")
+        } catch (e: IllegalArgumentException) { }
+    }
+}