Specialize Progression first/last/OrNull functions #KT-42178

libraries/stdlib/api/js-v1/kotlin.ranges.kt

@@ -327,6 +327,66 @@ public infix fun kotlin.ULong.downTo(to: kotlin.ULong): kotlin.ranges.ULongProgr
 @kotlin.WasExperimental(markerClass = {kotlin.ExperimentalUnsignedTypes::class})
 public infix fun kotlin.UShort.downTo(to: kotlin.UShort): kotlin.ranges.UIntProgression
 
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.first(): kotlin.Char
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.first(): kotlin.Int
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.first(): kotlin.Long
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.first(): kotlin.UInt
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.first(): kotlin.ULong
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.firstOrNull(): kotlin.Char?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.firstOrNull(): kotlin.Int?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.firstOrNull(): kotlin.Long?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.firstOrNull(): kotlin.UInt?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.firstOrNull(): kotlin.ULong?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.last(): kotlin.Char
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.last(): kotlin.Int
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.last(): kotlin.Long
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.last(): kotlin.UInt
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.last(): kotlin.ULong
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.lastOrNull(): kotlin.Char?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.lastOrNull(): kotlin.Int?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.lastOrNull(): kotlin.Long?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.lastOrNull(): kotlin.UInt?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.lastOrNull(): kotlin.ULong?
+
 @kotlin.SinceKotlin(version = "1.3")
 @kotlin.internal.InlineOnly
 public inline fun kotlin.ranges.CharRange.random(): kotlin.Char

libraries/stdlib/api/js/kotlin.ranges.kt

@@ -327,6 +327,66 @@ public infix fun kotlin.ULong.downTo(to: kotlin.ULong): kotlin.ranges.ULongProgr
 @kotlin.WasExperimental(markerClass = {kotlin.ExperimentalUnsignedTypes::class})
 public infix fun kotlin.UShort.downTo(to: kotlin.UShort): kotlin.ranges.UIntProgression
 
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.first(): kotlin.Char
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.first(): kotlin.Int
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.first(): kotlin.Long
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.first(): kotlin.UInt
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.first(): kotlin.ULong
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.firstOrNull(): kotlin.Char?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.firstOrNull(): kotlin.Int?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.firstOrNull(): kotlin.Long?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.firstOrNull(): kotlin.UInt?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.firstOrNull(): kotlin.ULong?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.last(): kotlin.Char
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.last(): kotlin.Int
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.last(): kotlin.Long
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.last(): kotlin.UInt
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.last(): kotlin.ULong
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.CharProgression.lastOrNull(): kotlin.Char?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.IntProgression.lastOrNull(): kotlin.Int?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.LongProgression.lastOrNull(): kotlin.Long?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.UIntProgression.lastOrNull(): kotlin.UInt?
+
+@kotlin.SinceKotlin(version = "1.7")
+public fun kotlin.ranges.ULongProgression.lastOrNull(): kotlin.ULong?
+
 @kotlin.SinceKotlin(version = "1.3")
 @kotlin.internal.InlineOnly
 public inline fun kotlin.ranges.CharRange.random(): kotlin.Char

libraries/stdlib/common/src/generated/_Arrays.kt

@@ -1005,8 +1005,9 @@ public inline fun CharArray.findLast(predicate: (Char) -> Boolean): Char? {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun <T> Array<out T>.first(): T {
     if (isEmpty())
@@ -1015,8 +1016,9 @@ public fun <T> Array<out T>.first(): T {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun ByteArray.first(): Byte {
     if (isEmpty())
@@ -1025,8 +1027,9 @@ public fun ByteArray.first(): Byte {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun ShortArray.first(): Short {
     if (isEmpty())
@@ -1035,8 +1038,9 @@ public fun ShortArray.first(): Short {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun IntArray.first(): Int {
     if (isEmpty())
@@ -1045,8 +1049,9 @@ public fun IntArray.first(): Int {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun LongArray.first(): Long {
     if (isEmpty())
@@ -1055,8 +1060,9 @@ public fun LongArray.first(): Long {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun FloatArray.first(): Float {
     if (isEmpty())
@@ -1065,8 +1071,9 @@ public fun FloatArray.first(): Float {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun DoubleArray.first(): Double {
     if (isEmpty())
@@ -1075,8 +1082,9 @@ public fun DoubleArray.first(): Double {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun BooleanArray.first(): Boolean {
     if (isEmpty())
@@ -1085,8 +1093,9 @@ public fun BooleanArray.first(): Boolean {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 public fun CharArray.first(): Char {
     if (isEmpty())

libraries/stdlib/common/src/generated/_Collections.kt

@@ -188,8 +188,9 @@ public inline fun <T> List<T>.findLast(predicate: (T) -> Boolean): T? {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the collection is empty.
+ * 
+ * @throws NoSuchElementException if the collection is empty.
  */
 public fun <T> Iterable<T>.first(): T {
     when (this) {
@@ -204,8 +205,9 @@ public fun <T> Iterable<T>.first(): T {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the list is empty.
+ * 
+ * @throws NoSuchElementException if the list is empty.
  */
 public fun <T> List<T>.first(): T {
     if (isEmpty())

libraries/stdlib/common/src/generated/_Ranges.kt

@@ -15,6 +15,138 @@ package kotlin.ranges
 
 import kotlin.random.*
 
+/**
+ * Returns the first element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun IntProgression.first(): Int {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.first
+}
+
+/**
+ * Returns the first element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun LongProgression.first(): Long {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.first
+}
+
+/**
+ * Returns the first element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun CharProgression.first(): Char {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.first
+}
+
+/**
+ * Returns the first element, or `null` if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun IntProgression.firstOrNull(): Int? {
+    return if (isEmpty()) null else this.first
+}
+
+/**
+ * Returns the first element, or `null` if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun LongProgression.firstOrNull(): Long? {
+    return if (isEmpty()) null else this.first
+}
+
+/**
+ * Returns the first element, or `null` if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun CharProgression.firstOrNull(): Char? {
+    return if (isEmpty()) null else this.first
+}
+
+/**
+ * Returns the last element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun IntProgression.last(): Int {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.last
+}
+
+/**
+ * Returns the last element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun LongProgression.last(): Long {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.last
+}
+
+/**
+ * Returns the last element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun CharProgression.last(): Char {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.last
+}
+
+/**
+ * Returns the last element, or `null` if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun IntProgression.lastOrNull(): Int? {
+    return if (isEmpty()) null else this.last
+}
+
+/**
+ * Returns the last element, or `null` if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun LongProgression.lastOrNull(): Long? {
+    return if (isEmpty()) null else this.last
+}
+
+/**
+ * Returns the last element, or `null` if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun CharProgression.lastOrNull(): Char? {
+    return if (isEmpty()) null else this.last
+}
+
 /**
  * Returns a random element from this range.
  * 

libraries/stdlib/common/src/generated/_Sequences.kt

@@ -100,10 +100,11 @@ public inline fun <T> Sequence<T>.findLast(predicate: (T) -> Boolean): T? {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the sequence is empty.
  *
  * The operation is _terminal_.
+ * 
+ * @throws NoSuchElementException if the sequence is empty.
  */
 public fun <T> Sequence<T>.first(): T {
     val iterator = iterator()

libraries/stdlib/common/src/generated/_Strings.kt

@@ -63,8 +63,9 @@ public inline fun CharSequence.findLast(predicate: (Char) -> Boolean): Char? {
 }
 
 /**
- * Returns first character.
+ * Returns the first character.
- * @throws [NoSuchElementException] if the char sequence is empty.
+ * 
+ * @throws NoSuchElementException if the char sequence is empty.
  */
 public fun CharSequence.first(): Char {
     if (isEmpty())

libraries/stdlib/common/src/generated/_UArrays.kt

@@ -507,8 +507,9 @@ public inline fun UShortArray.findLast(predicate: (UShort) -> Boolean): UShort?
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 @SinceKotlin("1.3")
 @ExperimentalUnsignedTypes
@@ -518,8 +519,9 @@ public inline fun UIntArray.first(): UInt {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 @SinceKotlin("1.3")
 @ExperimentalUnsignedTypes
@@ -529,8 +531,9 @@ public inline fun ULongArray.first(): ULong {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 @SinceKotlin("1.3")
 @ExperimentalUnsignedTypes
@@ -540,8 +543,9 @@ public inline fun UByteArray.first(): UByte {
 }
 
 /**
- * Returns first element.
+ * Returns the first element.
- * @throws [NoSuchElementException] if the array is empty.
+ * 
+ * @throws NoSuchElementException if the array is empty.
  */
 @SinceKotlin("1.3")
 @ExperimentalUnsignedTypes

libraries/stdlib/common/src/generated/_URanges.kt

@@ -15,6 +15,94 @@ package kotlin.ranges
 
 import kotlin.random.*
 
+/**
+ * Returns the first element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun UIntProgression.first(): UInt {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.first
+}
+
+/**
+ * Returns the first element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun ULongProgression.first(): ULong {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.first
+}
+
+/**
+ * Returns the first element, or `null` if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun UIntProgression.firstOrNull(): UInt? {
+    return if (isEmpty()) null else this.first
+}
+
+/**
+ * Returns the first element, or `null` if the progression is empty.
+ */
+@SinceKotlin("1.7")
+public fun ULongProgression.firstOrNull(): ULong? {
+    return if (isEmpty()) null else this.first
+}
+
+/**
+ * Returns the last element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun UIntProgression.last(): UInt {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.last
+}
+
+/**
+ * Returns the last element.
+ * 
+ * @throws NoSuchElementException if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun ULongProgression.last(): ULong {
+    if (isEmpty())
+        throw NoSuchElementException("Progression $this is empty.")
+    return this.last
+}
+
+/**
+ * Returns the last element, or `null` if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun UIntProgression.lastOrNull(): UInt? {
+    return if (isEmpty()) null else this.last
+}
+
+/**
+ * Returns the last element, or `null` if the progression is empty.
+ * 
+ * @sample samples.collections.Collections.Elements.last
+ */
+@SinceKotlin("1.7")
+public fun ULongProgression.lastOrNull(): ULong? {
+    return if (isEmpty()) null else this.last
+}
+
 /**
  * Returns a random element from this range.
  * 

libraries/stdlib/test/ranges/RangeTest.kt

@@ -399,4 +399,32 @@ public class RangeTest {
         assertNull(LongRange.EMPTY.randomOrNull())
         assertNull(CharRange.EMPTY.randomOrNull())
     }
+
+    @Test fun firstInEmptyRange() {
+        assertFailsWith<NoSuchElementException> { IntRange.EMPTY.first() }
+        assertFailsWith<NoSuchElementException> { LongRange.EMPTY.first() }
+        assertFailsWith<NoSuchElementException> { CharRange.EMPTY.first() }
+        assertFailsWith<NoSuchElementException> { IntProgression.fromClosedRange(0, 3, -2).first() }
+    }
+
+    @Test fun firstOrNullInEmptyRange() {
+        assertNull(IntRange.EMPTY.firstOrNull())
+        assertNull(LongRange.EMPTY.firstOrNull())
+        assertNull(CharRange.EMPTY.firstOrNull())
+        assertNull(IntProgression.fromClosedRange(0, 3, -2).firstOrNull())
+    }
+
+    @Test fun lastInEmptyRange() {
+        assertFailsWith<NoSuchElementException> { IntRange.EMPTY.last() }
+        assertFailsWith<NoSuchElementException> { LongRange.EMPTY.last() }
+        assertFailsWith<NoSuchElementException> { CharRange.EMPTY.last() }
+        assertFailsWith<NoSuchElementException> { IntProgression.fromClosedRange(0, 3, -2).last() }
+    }
+
+    @Test fun lastOrNullInEmptyRange() {
+        assertNull(IntRange.EMPTY.lastOrNull())
+        assertNull(LongRange.EMPTY.lastOrNull())
+        assertNull(CharRange.EMPTY.lastOrNull())
+        assertNull(IntProgression.fromClosedRange(0, 3, -2).lastOrNull())
+    }
 }

libraries/stdlib/test/ranges/URangeTest.kt

@@ -241,4 +241,28 @@ public class URangeTest {
         assertFailsWith<NoSuchElementException> { UIntRange.EMPTY.random() }
         assertFailsWith<NoSuchElementException> { ULongRange.EMPTY.random() }
     }
+
+    @Test fun firstInEmptyRange() {
+        assertFailsWith<NoSuchElementException> { UIntRange.EMPTY.first() }
+        assertFailsWith<NoSuchElementException> { ULongRange.EMPTY.first() }
+        assertFailsWith<NoSuchElementException> { UIntProgression.fromClosedRange(0u, 3u, -2).first() }
+    }
+
+    @Test fun firstOrNullInEmptyRange() {
+        assertNull(UIntRange.EMPTY.firstOrNull())
+        assertNull(ULongRange.EMPTY.firstOrNull())
+        assertNull(UIntProgression.fromClosedRange(0u, 3u, -2).firstOrNull())
+    }
+
+    @Test fun lastInEmptyRange() {
+        assertFailsWith<NoSuchElementException> { UIntRange.EMPTY.last() }
+        assertFailsWith<NoSuchElementException> { ULongRange.EMPTY.last() }
+        assertFailsWith<NoSuchElementException> { UIntProgression.fromClosedRange(0u, 3u, -2).last() }
+    }
+
+    @Test fun lastOrNullInEmptyRange() {
+        assertNull(UIntRange.EMPTY.lastOrNull())
+        assertNull(ULongRange.EMPTY.lastOrNull())
+        assertNull(UIntProgression.fromClosedRange(0u, 3u, -2).lastOrNull())
+    }
 }

libraries/tools/binary-compatibility-validator/reference-public-api/kotlin-stdlib-runtime-merged.txt

@@ -4491,6 +4491,12 @@ public final class kotlin/ranges/RangesKt {
 	public static final fun downTo (SI)Lkotlin/ranges/IntProgression;
 	public static final fun downTo (SJ)Lkotlin/ranges/LongProgression;
 	public static final fun downTo (SS)Lkotlin/ranges/IntProgression;
+	public static final fun first (Lkotlin/ranges/CharProgression;)C
+	public static final fun first (Lkotlin/ranges/IntProgression;)I
+	public static final fun first (Lkotlin/ranges/LongProgression;)J
+	public static final fun firstOrNull (Lkotlin/ranges/CharProgression;)Ljava/lang/Character;
+	public static final fun firstOrNull (Lkotlin/ranges/IntProgression;)Ljava/lang/Integer;
+	public static final fun firstOrNull (Lkotlin/ranges/LongProgression;)Ljava/lang/Long;
 	public static final synthetic fun floatRangeContains (Lkotlin/ranges/ClosedRange;B)Z
 	public static final fun floatRangeContains (Lkotlin/ranges/ClosedRange;D)Z
 	public static final synthetic fun floatRangeContains (Lkotlin/ranges/ClosedRange;I)Z
@@ -4501,6 +4507,12 @@ public final class kotlin/ranges/RangesKt {
 	public static final synthetic fun intRangeContains (Lkotlin/ranges/ClosedRange;F)Z
 	public static final fun intRangeContains (Lkotlin/ranges/ClosedRange;J)Z
 	public static final fun intRangeContains (Lkotlin/ranges/ClosedRange;S)Z
+	public static final fun last (Lkotlin/ranges/CharProgression;)C
+	public static final fun last (Lkotlin/ranges/IntProgression;)I
+	public static final fun last (Lkotlin/ranges/LongProgression;)J
+	public static final fun lastOrNull (Lkotlin/ranges/CharProgression;)Ljava/lang/Character;
+	public static final fun lastOrNull (Lkotlin/ranges/IntProgression;)Ljava/lang/Integer;
+	public static final fun lastOrNull (Lkotlin/ranges/LongProgression;)Ljava/lang/Long;
 	public static final fun longRangeContains (Lkotlin/ranges/ClosedRange;B)Z
 	public static final synthetic fun longRangeContains (Lkotlin/ranges/ClosedRange;D)Z
 	public static final synthetic fun longRangeContains (Lkotlin/ranges/ClosedRange;F)Z
@@ -4640,6 +4652,14 @@ public final class kotlin/ranges/URangesKt {
 	public static final fun downTo-J1ME1BU (II)Lkotlin/ranges/UIntProgression;
 	public static final fun downTo-Kr8caGY (BB)Lkotlin/ranges/UIntProgression;
 	public static final fun downTo-eb3DHEI (JJ)Lkotlin/ranges/ULongProgression;
+	public static final fun first (Lkotlin/ranges/UIntProgression;)I
+	public static final fun first (Lkotlin/ranges/ULongProgression;)J
+	public static final fun firstOrNull (Lkotlin/ranges/UIntProgression;)Lkotlin/UInt;
+	public static final fun firstOrNull (Lkotlin/ranges/ULongProgression;)Lkotlin/ULong;
+	public static final fun last (Lkotlin/ranges/UIntProgression;)I
+	public static final fun last (Lkotlin/ranges/ULongProgression;)J
+	public static final fun lastOrNull (Lkotlin/ranges/UIntProgression;)Lkotlin/UInt;
+	public static final fun lastOrNull (Lkotlin/ranges/ULongProgression;)Lkotlin/ULong;
 	public static final fun random (Lkotlin/ranges/UIntRange;Lkotlin/random/Random;)I
 	public static final fun random (Lkotlin/ranges/ULongRange;Lkotlin/random/Random;)J
 	public static final fun randomOrNull (Lkotlin/ranges/UIntRange;Lkotlin/random/Random;)Lkotlin/UInt;

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

@@ -26,6 +26,11 @@ object Elements : TemplateGroupBase() {
                     sourceFile(SourceFile.URanges)
                 }
             }
+            specialFor(ProgressionsOfPrimitives) {
+                if (primitive in PrimitiveType.unsignedPrimitives) {
+                    sourceFile(SourceFile.URanges)
+                }
+            }
         }
     }
 
@@ -443,10 +448,13 @@ object Elements : TemplateGroupBase() {
     val f_first = fn("first()") {
         includeDefault()
         include(CharSequences, Lists, ArraysOfUnsigned)
+        include(ProgressionsOfPrimitives, PrimitiveType.rangePrimitives)
     } builder {
-        doc { """Returns first ${f.element}.
+        specialFor(ProgressionsOfPrimitives) {
-        @throws [NoSuchElementException] if the ${f.collection} is empty.
+            since("1.7")
-        """ }
+        }
+        doc { "Returns the first ${f.element}." }
+        throws("NoSuchElementException", "if the ${f.collection} is empty.")
         returns("T")
         body {
             """
@@ -476,6 +484,13 @@ object Elements : TemplateGroupBase() {
             return iterator.next()
             """
         }
+        body(ProgressionsOfPrimitives) {
+            """
+            if (isEmpty())
+                throw NoSuchElementException("Progression ${'$'}this is empty.")
+            return this.first
+            """
+        }
 
         specialFor(ArraysOfUnsigned) {
             inlineOnly()
@@ -486,7 +501,11 @@ object Elements : TemplateGroupBase() {
     val f_firstOrNull = fn("firstOrNull()") {
         includeDefault()
         include(CharSequences, Lists, ArraysOfUnsigned)
+        include(ProgressionsOfPrimitives, PrimitiveType.rangePrimitives)
     } builder {
+        specialFor(ProgressionsOfPrimitives) {
+            since("1.7")
+        }
         doc { "Returns the first ${f.element}, or `null` if the ${f.collection} is empty." }
         returns("T?")
         body {
@@ -520,6 +539,11 @@ object Elements : TemplateGroupBase() {
             return iterator.next()
             """
         }
+        body(ProgressionsOfPrimitives) {
+            """
+            return if (isEmpty()) null else this.first
+            """
+        }
     }
 
     val f_first_predicate = fn("first(predicate: (T) -> Boolean)") {
@@ -578,7 +602,11 @@ object Elements : TemplateGroupBase() {
     val f_last = fn("last()") {
         includeDefault()
         include(CharSequences, Lists, ArraysOfUnsigned)
+        include(ProgressionsOfPrimitives, PrimitiveType.rangePrimitives)
     } builder {
+        specialFor(ProgressionsOfPrimitives) {
+            since("1.7")
+        }
         doc { "Returns the last ${f.element}." }
         throws("NoSuchElementException", "if the ${f.collection} is empty.")
         sample("${f.sampleClass}.last")
@@ -617,6 +645,13 @@ object Elements : TemplateGroupBase() {
             return this[lastIndex]
             """
         }
+        body(ProgressionsOfPrimitives) {
+            """
+            if (isEmpty())
+                throw NoSuchElementException("Progression ${'$'}this is empty.")
+            return this.last
+            """
+        }
 
         specialFor(ArraysOfUnsigned) {
             inlineOnly()
@@ -627,7 +662,11 @@ object Elements : TemplateGroupBase() {
     val f_lastOrNull = fn("lastOrNull()") {
         includeDefault()
         include(Lists, CharSequences, ArraysOfUnsigned)
+        include(ProgressionsOfPrimitives, PrimitiveType.rangePrimitives)
     } builder {
+        specialFor(ProgressionsOfPrimitives) {
+            since("1.7")
+        }
         doc { "Returns the last ${f.element}, or `null` if the ${f.collection} is empty." }
         sample("${f.sampleClass}.last")
         returns("T?")
@@ -668,6 +707,11 @@ object Elements : TemplateGroupBase() {
             return if (isEmpty()) null else this[size - 1]
             """
         }
+        body(ProgressionsOfPrimitives) {
+            """
+            return if (isEmpty()) null else this.last
+            """
+        }
     }
 
     val f_last_predicate = fn("last(predicate: (T) -> Boolean)") {

libraries/tools/kotlin-stdlib-gen/src/templates/dsl/FamilyProperties.kt

@@ -34,6 +34,7 @@ object DocExtensions {
             CharSequences -> "char sequence"
             ArraysOfObjects, ArraysOfPrimitives, InvariantArraysOfObjects, ArraysOfUnsigned -> "array"
             Ranges, RangesOfPrimitives -> "range"
+            ProgressionsOfPrimitives -> "progression"
             Strings, Sequences, Maps, Lists, Sets -> name.singularize().decapitalize()
             else -> "collection"
         }