Generate to[Primitive]Array() methods for generic arrays and collections.

#KT-4180 Fixed

libraries/stdlib/src/generated/_ArraysToPrimitiveArrays.kt

@@ -0,0 +1,180 @@
+package kotlin
+
+//
+// NOTE THIS FILE IS AUTO-GENERATED by the GenerateStandardLib.kt
+// See: https://github.com/JetBrains/kotlin/tree/master/libraries/stdlib
+//
+
+import kotlin.platform.*
+import java.util.*
+
+import java.util.Collections // TODO: it's temporary while we have java.util.Collections in js
+
+/**
+ * Returns an array of Boolean containing all of the elements of this generic array.
+ */
+public fun Array<out Boolean>.toBooleanArray(): BooleanArray {
+    val result = BooleanArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Boolean containing all of the elements of this collection.
+ */
+public fun Collection<Boolean>.toBooleanArray(): BooleanArray {
+    val result = BooleanArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Byte containing all of the elements of this generic array.
+ */
+public fun Array<out Byte>.toByteArray(): ByteArray {
+    val result = ByteArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Byte containing all of the elements of this collection.
+ */
+public fun Collection<Byte>.toByteArray(): ByteArray {
+    val result = ByteArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Char containing all of the elements of this generic array.
+ */
+public fun Array<out Char>.toCharArray(): CharArray {
+    val result = CharArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Char containing all of the elements of this collection.
+ */
+public fun Collection<Char>.toCharArray(): CharArray {
+    val result = CharArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Double containing all of the elements of this generic array.
+ */
+public fun Array<out Double>.toDoubleArray(): DoubleArray {
+    val result = DoubleArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Double containing all of the elements of this collection.
+ */
+public fun Collection<Double>.toDoubleArray(): DoubleArray {
+    val result = DoubleArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Float containing all of the elements of this generic array.
+ */
+public fun Array<out Float>.toFloatArray(): FloatArray {
+    val result = FloatArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Float containing all of the elements of this collection.
+ */
+public fun Collection<Float>.toFloatArray(): FloatArray {
+    val result = FloatArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Int containing all of the elements of this generic array.
+ */
+public fun Array<out Int>.toIntArray(): IntArray {
+    val result = IntArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Int containing all of the elements of this collection.
+ */
+public fun Collection<Int>.toIntArray(): IntArray {
+    val result = IntArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Long containing all of the elements of this generic array.
+ */
+public fun Array<out Long>.toLongArray(): LongArray {
+    val result = LongArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Long containing all of the elements of this collection.
+ */
+public fun Collection<Long>.toLongArray(): LongArray {
+    val result = LongArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+
+/**
+ * Returns an array of Short containing all of the elements of this generic array.
+ */
+public fun Array<out Short>.toShortArray(): ShortArray {
+    val result = ShortArray(size())
+    for (index in indices)
+        result[index] = this[index]
+    return result
+}
+
+/**
+ * Returns an array of Short containing all of the elements of this collection.
+ */
+public fun Collection<Short>.toShortArray(): ShortArray {
+    val result = ShortArray(size())
+    var index = 0
+    for (element in this)
+        result[index++] = element
+    return result
+}
+

libraries/stdlib/test/collections/ArraysTest.kt

@@ -295,6 +295,18 @@ class ArraysTest {
         assertEquals(10, intsAsList[1], "Should reflect changes in original array")
     }
 
+    test fun toPrimitiveArray() {
+        val genericArray: Array<Int> = array(1, 2, 3)
+        val primitiveArray: IntArray = genericArray.toIntArray()
+        expect(3) { primitiveArray.size() }
+        assertEquals(genericArray.asList(), primitiveArray.asList())
+
+
+        val charList = listOf('a', 'b')
+        val charArray: CharArray = charList.toCharArray()
+        assertEquals(charList, charArray.asList())
+    }
+
     /*
 
     TODO FIXME ASAP: These currently fail on JS due to missing upto() method on numbers

libraries/tools/kotlin-stdlib-gen/src/generators/GenerateCollections.kt

@@ -21,6 +21,14 @@ fun generateCollectionsAPI(outDir: File) {
     specialJVM().writeTo(File(outDir, "_SpecialJVM.kt")) { build() }
     ranges().writeTo(File(outDir, "_Ranges.kt")) { build() }
 
+    toPrimitiveArrays().writeTo(File(outDir, "_ArraysToPrimitiveArrays.kt")) {
+        val builder = StringBuilder()
+        for (family in buildFamilies)
+            build(builder, family, buildPrimitives.single())
+
+        builder.toString()
+    }
+
     numeric().writeTo(File(outDir, "_Numeric.kt")) {
         val builder = StringBuilder()
         for (numeric in numericPrimitives)

libraries/tools/kotlin-stdlib-gen/src/templates/Arrays.kt

@@ -56,3 +56,34 @@ fun arrays(): List<GenericFunction> {
 
     return templates
 }
+
+
+
+fun toPrimitiveArrays(): List<GenericFunction> =
+    PrimitiveType.values().map { primitive ->
+        val arrayType = primitive.name + "Array"
+        f("to$arrayType()") {
+            only(ArraysOfObjects, Collections)
+            only(primitive)
+            doc(ArraysOfObjects) { "Returns an array of ${primitive.name} containing all of the elements of this generic array." }
+            doc(Collections) { "Returns an array of ${primitive.name} containing all of the elements of this collection." }
+            returns(arrayType)
+            body {
+                """
+                val result = $arrayType(size())
+                for (index in indices)
+                    result[index] = this[index]
+                return result
+                """
+            }
+            body(Collections) {
+                """
+                val result = $arrayType(size())
+                var index = 0
+                for (element in this)
+                    result[index++] = element
+                return result
+                """
+            }
+        }
+    }