From d19f9ee0c5a2c193504b3c7a397d632a601a097e Mon Sep 17 00:00:00 2001
From: Ilya Gorbunov <ilya.gorbunov@jetbrains.com>
Date: Fri, 22 May 2020 01:10:05 +0300
Subject: [PATCH] Simplify min/max implementation

---
 .../stdlib/common/src/generated/_Arrays.kt    | 32 +++++--------------
 .../common/src/generated/_Collections.kt      | 16 +++-------
 .../stdlib/common/src/generated/_Sequences.kt | 16 +++-------
 .../stdlib/test/collections/CollectionTest.kt |  6 ++++
 .../src/templates/Aggregates.kt               | 26 +++++++--------
 5 files changed, 33 insertions(+), 63 deletions(-)

diff --git a/libraries/stdlib/common/src/generated/_Arrays.kt b/libraries/stdlib/common/src/generated/_Arrays.kt
index 9b709991a3f..1250d31aac3 100644
--- a/libraries/stdlib/common/src/generated/_Arrays.kt
+++ b/libraries/stdlib/common/src/generated/_Arrays.kt
@@ -13084,11 +13084,9 @@ public inline fun CharArray.forEachIndexed(action: (index: Int, Char) -> Unit):
 public fun Array<out Double>.max(): Double? {
     if (isEmpty()) return null
     var max = this[0]
-    if (max.isNaN()) return max
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -13102,11 +13100,9 @@ public fun Array<out Double>.max(): Double? {
 public fun Array<out Float>.max(): Float? {
     if (isEmpty()) return null
     var max = this[0]
-    if (max.isNaN()) return max
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -13184,11 +13180,9 @@ public fun LongArray.max(): Long? {
 public fun FloatArray.max(): Float? {
     if (isEmpty()) return null
     var max = this[0]
-    if (max.isNaN()) return max
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -13201,11 +13195,9 @@ public fun FloatArray.max(): Float? {
 public fun DoubleArray.max(): Double? {
     if (isEmpty()) return null
     var max = this[0]
-    if (max.isNaN()) return max
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -15059,11 +15051,9 @@ public fun CharArray.maxWith(comparator: Comparator<in Char>): Char? {
 public fun Array<out Double>.min(): Double? {
     if (isEmpty()) return null
     var min = this[0]
-    if (min.isNaN()) return min
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
@@ -15077,11 +15067,9 @@ public fun Array<out Double>.min(): Double? {
 public fun Array<out Float>.min(): Float? {
     if (isEmpty()) return null
     var min = this[0]
-    if (min.isNaN()) return min
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
@@ -15159,11 +15147,9 @@ public fun LongArray.min(): Long? {
 public fun FloatArray.min(): Float? {
     if (isEmpty()) return null
     var min = this[0]
-    if (min.isNaN()) return min
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
@@ -15176,11 +15162,9 @@ public fun FloatArray.min(): Float? {
 public fun DoubleArray.min(): Double? {
     if (isEmpty()) return null
     var min = this[0]
-    if (min.isNaN()) return min
     for (i in 1..lastIndex) {
         val e = this[i]
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
diff --git a/libraries/stdlib/common/src/generated/_Collections.kt b/libraries/stdlib/common/src/generated/_Collections.kt
index 15c4af755ae..12b130c9c30 100644
--- a/libraries/stdlib/common/src/generated/_Collections.kt
+++ b/libraries/stdlib/common/src/generated/_Collections.kt
@@ -1729,11 +1729,9 @@ public fun Iterable<Double>.max(): Double? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var max = iterator.next()
-    if (max.isNaN()) return max
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -1748,11 +1746,9 @@ public fun Iterable<Float>.max(): Float? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var max = iterator.next()
-    if (max.isNaN()) return max
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -1993,11 +1989,9 @@ public fun Iterable<Double>.min(): Double? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var min = iterator.next()
-    if (min.isNaN()) return min
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
@@ -2012,11 +2006,9 @@ public fun Iterable<Float>.min(): Float? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var min = iterator.next()
-    if (min.isNaN()) return min
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
diff --git a/libraries/stdlib/common/src/generated/_Sequences.kt b/libraries/stdlib/common/src/generated/_Sequences.kt
index 297bde74066..41fd8fbd458 100644
--- a/libraries/stdlib/common/src/generated/_Sequences.kt
+++ b/libraries/stdlib/common/src/generated/_Sequences.kt
@@ -1178,11 +1178,9 @@ public fun Sequence<Double>.max(): Double? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var max = iterator.next()
-    if (max.isNaN()) return max
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -1199,11 +1197,9 @@ public fun Sequence<Float>.max(): Float? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var max = iterator.next()
-    if (max.isNaN()) return max
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (max < e) max = e
+        max = maxOf(max, e)
     }
     return max
 }
@@ -1468,11 +1464,9 @@ public fun Sequence<Double>.min(): Double? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var min = iterator.next()
-    if (min.isNaN()) return min
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
@@ -1489,11 +1483,9 @@ public fun Sequence<Float>.min(): Float? {
     val iterator = iterator()
     if (!iterator.hasNext()) return null
     var min = iterator.next()
-    if (min.isNaN()) return min
     while (iterator.hasNext()) {
         val e = iterator.next()
-        if (e.isNaN()) return e
-        if (min > e) min = e
+        min = minOf(min, e)
     }
     return min
 }
diff --git a/libraries/stdlib/test/collections/CollectionTest.kt b/libraries/stdlib/test/collections/CollectionTest.kt
index dfb6d08e8a1..a424def797e 100644
--- a/libraries/stdlib/test/collections/CollectionTest.kt
+++ b/libraries/stdlib/test/collections/CollectionTest.kt
@@ -832,6 +832,9 @@ class CollectionTest {
         expect("a", { listOf("a", "b").min() })
         expect(null, { listOf<Int>().asSequence().min() })
         expect(2, { listOf(2, 3).asSequence().min() })
+
+        assertIsNegativeZero(listOf(0.0, -0.0).shuffled().min()!!)
+        assertIsNegativeZero(listOf(0.0F, -0.0F).shuffled().min()!!.toDouble())
     }
 
     @Test fun max() {
@@ -843,6 +846,9 @@ class CollectionTest {
         expect("b", { listOf("a", "b").max() })
         expect(null, { listOf<Int>().asSequence().max() })
         expect(3, { listOf(2, 3).asSequence().max() })
+
+        assertIsPositiveZero(listOf(0.0, -0.0).shuffled().max()!!)
+        assertIsPositiveZero(listOf(0.0F, -0.0F).shuffled().max()!!.toDouble())
     }
 
     @Test fun minWith() {
diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
index 685035462e3..44f43c16732 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/Aggregates.kt
@@ -329,38 +329,34 @@ object Aggregates : TemplateGroupBase() {
                 }
                 returns("T?")
 
+                val acc = op
+                val cmpBlock = if (isFloat)
+                    """$acc = ${op}Of($acc, e)"""
+                else
+                    """if ($acc ${if (op == "max") "<" else ">"} e) $acc = e"""
                 body {
                     """
                     val iterator = iterator()
                     if (!iterator.hasNext()) return null
-                    var $op = iterator.next()
-                    ${if (isFloat) "if ($op.isNaN()) return $op" else "\\"}
-
+                    var $acc = iterator.next()
                     while (iterator.hasNext()) {
                         val e = iterator.next()
-                        ${if (isFloat) "if (e.isNaN()) return e" else "\\"}
-                        if ($op ${if (op == "max") "<" else ">"} e) $op = e
+                        $cmpBlock
                     }
-                    return $op
+                    return $acc
                     """
                 }
                 body(ArraysOfObjects, ArraysOfPrimitives, CharSequences, ArraysOfUnsigned) {
                     """
                     if (isEmpty()) return null
-                    var $op = this[0]
-                    ${if (isFloat) "if ($op.isNaN()) return $op" else "\\"}
-
+                    var $acc = this[0]
                     for (i in 1..lastIndex) {
                         val e = this[i]
-                        ${if (isFloat) "if (e.isNaN()) return e" else "\\"}
-                        if ($op ${if (op == "max") "<" else ">"} e) $op = e
+                        $cmpBlock
                     }
-                    return $op
+                    return $acc
                     """
                 }
-                body {
-                    body!!.replace(Regex("""^\s+\\\n""", RegexOption.MULTILINE), "") // remove empty lines ending with \
-                }
             }
         }
     }