standard library: 'sum' function added (KT-3714, KT-3843, KT-3126)

libraries/stdlib/src/generated/_Arrays.kt

@@ -408,3 +408,45 @@ public inline fun <T> Array<out T>.withIndices() : Iterator<Pair<Int, T>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun Array<Byte>.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Array<Short>.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Array<Int>.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Array<Long>.sum() : Long {
+    return fold(0.toLong(), {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Array<Float>.sum() : Float {
+    return fold(0.toFloat(), {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Array<Double>.sum() : Double {
+    return fold(0.0, {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_ByteArrays.kt

@@ -381,3 +381,10 @@ public inline fun ByteArray.withIndices() : Iterator<Pair<Int, Byte>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun ByteArray.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_DoubleArrays.kt

@@ -381,3 +381,10 @@ public inline fun DoubleArray.withIndices() : Iterator<Pair<Int, Double>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun DoubleArray.sum() : Double {
+    return fold(0.0, {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_FloatArrays.kt

@@ -381,3 +381,10 @@ public inline fun FloatArray.withIndices() : Iterator<Pair<Int, Float>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun FloatArray.sum() : Float {
+    return fold(0.toFloat(), {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_IntArrays.kt

@@ -381,3 +381,10 @@ public inline fun IntArray.withIndices() : Iterator<Pair<Int, Int>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun IntArray.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_Iterables.kt

@@ -376,3 +376,31 @@ public inline fun <T> Iterable<T>.withIndices() : Iterator<Pair<Int, T>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun Iterable<Int>.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Iterable<Long>.sum() : Long {
+    return fold(0.toLong(), {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Iterable<Float>.sum() : Float {
+    return fold(0.toFloat(), {a,b -> a+b})
+}
+
+/**
+ * Sums up the elements
+ */
+public fun Iterable<Double>.sum() : Double {
+    return fold(0.0, {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_LongArrays.kt

@@ -381,3 +381,10 @@ public inline fun LongArray.withIndices() : Iterator<Pair<Int, Long>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun LongArray.sum() : Long {
+    return fold(0.toLong(), {a,b -> a+b})
+}
+

libraries/stdlib/src/generated/_ShortArrays.kt

@@ -381,3 +381,10 @@ public inline fun ShortArray.withIndices() : Iterator<Pair<Int, Short>> {
     return IndexIterator(iterator())
 }
 
+/**
+ * Sums up the elements
+ */
+public fun ShortArray.sum() : Int {
+    return fold(0, {a,b -> a+b})
+}
+

libraries/stdlib/test/ArraysJVMTest.kt

@@ -58,4 +58,14 @@ class ArraysJVMTest {
             intArray().reduceRight { a, b -> a + b}
         }
     }
+
+    test fun sum() {
+        expect(0) { intArray().sum() }
+        expect(14) { intArray(2, 3, 9).sum() }
+        expect(3.0) { doubleArray(1.0, 2.0).sum() }
+        expect(200) { byteArray(100, 100).sum() }
+        expect(50000) { shortArray(20000, 30000).sum() }
+        expect(3000000000000) { longArray(1000000000000, 2000000000000).sum() }
+        expect(3.0) { floatArray(1.0, 2.0).sum() }
+    }
 }

libraries/stdlib/test/ArraysTest.kt

@@ -101,6 +101,16 @@ class ArraysTest {
         assertEquals(false, arr[1])
     }
 
+    test fun sum() {
+        expect(0) { array<Int>().sum() }
+        expect(14) { array(2, 3, 9).sum() }
+        expect(3.0) { array(1.0, 2.0).sum() }
+        expect(200) { array<Byte>(100, 100).sum() }
+        expect(50000) { array<Short>(20000, 30000).sum() }
+        //TODO: uncomment when toLong() will be supported
+        //expect(3000000000000) { array<Long>(1000000000000, 2000000000000).sum() }
+        expect(3.0) { array<Float>(1.0, 2.0).sum() }
+    }
     /*
 
     TODO FIXME ASAP: These currently fail on JS due to missing upto() method on numbers

libraries/stdlib/test/CollectionTest.kt

@@ -414,6 +414,14 @@ class CollectionTest {
         expect(arrayList(2, 3, 1)) { list }
     }
 
+    test fun sum() {
+        expect(0) { ArrayList<Int>().sum() }
+        expect(14) { arrayListOf(2, 3, 9).sum() }
+        expect(3.0) { arrayListOf(1.0, 2.0).sum() }
+        expect(3000000000000) { arrayListOf<Long>(1000000000000, 2000000000000).sum() }
+        expect(3.0) { arrayListOf<Float>(1.0, 2.0).sum() }
+    }
+
     class IterableWrapper<T>(collection : Iterable<T>) : Iterable<T> {
         private val collection = collection
 

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

@@ -29,27 +29,27 @@ fun main(args: Array<String>) {
     generateDomEventsAPI(File(jsCoreDir, "domEvents.kt"))
 
     iterators().writeTo(File(outDir, "_Iterators.kt")) {
-        buildFor(Iterators, "")
+        buildFor(Iterators, null)
     }
 
     val iterables = iterables()
-    iterables.writeTo(File(outDir, "_Arrays.kt")) {
-        buildFor(Arrays, "")
+    val sumFunctions = PrimitiveType.values().map(::sumFunction).filterNotNull()
+    (iterables + sumFunctions).writeTo(File(outDir, "_Arrays.kt")) {
+        buildFor(Arrays, null)
     }
 
-    val otherArrayNames = arrayListOf("Boolean", "Byte", "Char", "Short", "Int", "Long", "Float", "Double")
-    for (a in otherArrayNames) {
-        iterables.writeTo(File(outDir, "_${a}Arrays.kt")) {
-            buildFor(PrimitiveArrays, a)
+    for (primitive in PrimitiveType.values()) {
+        (iterables + sumFunction(primitive)).filterNotNull().writeTo(File(outDir, "_${primitive.name}Arrays.kt")) {
+            buildFor(PrimitiveArrays, primitive)
         }
     }
 
-    iterables.writeTo(File(outDir, "_Iterables.kt")) {
-        buildFor(Iterables, "")
+    (iterables + sumFunctions).writeTo(File(outDir, "_Iterables.kt")) {
+        buildFor(Iterables, null)
     }
 
     collections().writeTo(File(outDir, "_Collections.kt")) {
-        buildFor(Collections, "")
+        buildFor(Collections, null)
     }
 
     generateDownTos(File(outDir, "_DownTo.kt"), "package kotlin")

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

@@ -18,7 +18,8 @@ enum class Family {
 class GenericFunction(val signature : String): Comparable<GenericFunction> {
     var doc : String = ""
     var toNullableT : Boolean = false
-    val isInline : Boolean = true;
+    var isInline : Boolean = true;
+    private val customReceivers = HashMap<Family, String>()
     val blockedFor = HashSet<Family>()
     val bodies = HashMap<Family, String>()
     val returnTypes = HashMap<Family, String>()
@@ -44,6 +45,10 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
         returnTypes[this] = r
     }
 
+    fun Family.customReceiver(r: String) {
+        customReceivers[this] = r
+    }
+
     fun typeParam(t:String) {
         typeParams.add(t)
     }
@@ -54,7 +59,7 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
 
     private fun effectiveTypeParams(f : Family) : List<String> {
         val types = ArrayList(typeParams)
-        if (typeParams.find { it.startsWith("T") } == null) {
+        if (typeParams.find { it.startsWith("T") } == null && !customReceivers.containsKey(f)) {
             types.add(0, "T")
         }
 
@@ -67,7 +72,7 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
 
 
 
-    fun buildFor(f: Family, arrName : String = "") : String {
+    fun buildFor(f: Family, primitiveType: PrimitiveType?) : String {
         if (blockedFor.contains(f)) return ""
 
         if (returnTypes[f] == null) throw RuntimeException("No return type specified for $signature")
@@ -78,7 +83,7 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
             Collections -> "Collection<T>"
             Iterators -> "Iterator<T>"
             Arrays -> "Array<out T>"
-            PrimitiveArrays -> "${arrName}Array"
+            PrimitiveArrays -> "${primitiveType!!.name}Array"
         }
 
         fun String.renderType() : String {
@@ -89,7 +94,7 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
                 val token = t.nextToken()
                 answer.append(when (token) {
                     "SELF" -> selftype
-                    "T" -> if (f == Family.PrimitiveArrays) arrName else token
+                    "T" -> if (f == Family.PrimitiveArrays) primitiveType!!.name else token
                     else -> token
                 })
             }
@@ -120,7 +125,7 @@ class GenericFunction(val signature : String): Comparable<GenericFunction> {
             builder.append(types.makeString(separator = ", ", prefix = "<", postfix = "> ").renderType())
         }
 
-        builder.append((
+        builder.append((customReceivers[f] ?:
         if (toNullableT) {
             selftype.replace("T>", "T?>")
         }
@@ -160,6 +165,6 @@ fun f(signature : String, init : GenericFunction.() -> Unit): GenericFunction {
 fun main(args : Array<String>) {
     val templates = collections()
     for (t in templates) {
-        print(t.buildFor(PrimitiveArrays, "Byte"))
+        print(t.buildFor(PrimitiveArrays, PrimitiveType.Byte))
     }
 }

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

@@ -0,0 +1,47 @@
+package templates
+
+import templates.Family.*
+
+enum class PrimitiveType(val name: String) {
+    Boolean: PrimitiveType("Boolean")
+    Byte: PrimitiveType("Byte")
+    Char: PrimitiveType("Char")
+    Short: PrimitiveType("Short")
+    Int: PrimitiveType("Int")
+    Long: PrimitiveType("Long")
+    Float: PrimitiveType("Float")
+    Double: PrimitiveType("Double")
+}
+
+private fun PrimitiveType.zero() = when (this) {
+    PrimitiveType.Int -> "0"
+    PrimitiveType.Byte -> "0"
+    PrimitiveType.Short -> "0"
+    PrimitiveType.Long -> "0.toLong()"
+    PrimitiveType.Double -> "0.0"
+    PrimitiveType.Float -> "0.toFloat()"
+    else -> null
+}
+
+private fun returnTypeForSum(primitive: PrimitiveType) = when (primitive) {
+    PrimitiveType.Byte -> PrimitiveType.Int
+    PrimitiveType.Short -> PrimitiveType.Int
+    else -> primitive
+}
+
+fun sumFunction(primitive: PrimitiveType) = primitive.zero()?.let { zero ->
+    f("sum()") {
+        doc = "Sums up the elements"
+        isInline = false
+        if (returnTypeForSum(primitive) != primitive) {
+            //this is required to avoid clash of erasured method signatures (Iterables.sum(): Int)
+            absentFor(Iterables)
+        }
+        Iterables.customReceiver("Iterable<${primitive.name}>")
+        Arrays.customReceiver("Array<${primitive.name}>")
+        returns(returnTypeForSum(primitive).name)
+        body {
+            "return fold($zero, {a,b -> a+b})"
+        }
+    }
+}