Inline all the things! 🎨

Sources/Algorithms/Chain.swift

@@ -19,7 +19,7 @@ public struct Chain2<Base1: Sequence, Base2: Sequence>
   /// The second sequence in this chain.
   public let base2: Base2
 
-  @usableFromInline
+  @inlinable
   internal init(base1: Base1, base2: Base2) {
     self.base1 = base1
     self.base2 = base2
@@ -35,7 +35,7 @@ extension Chain2: Sequence {
     @usableFromInline
     internal var iterator2: Base2.Iterator
 
-    @usableFromInline
+    @inlinable
     internal init(_ concatenation: Chain2) {
       iterator1 = concatenation.base1.makeIterator()
       iterator2 = concatenation.base2.makeIterator()
@@ -71,13 +71,13 @@ extension Chain2: Collection where Base1: Collection, Base2: Collection {
     internal let position: Representation
 
     /// Creates a new index into the first underlying collection.
-    @usableFromInline
+    @inlinable
     internal init(first i: Base1.Index) {
       position = .first(i)
     }
 
     /// Creates a new index into the second underlying collection.
-    @usableFromInline
+    @inlinable
     internal init(second i: Base2.Index) {
       position = .second(i)
     }
@@ -99,7 +99,7 @@ extension Chain2: Collection where Base1: Collection, Base2: Collection {
 
   /// Converts an index of `Base1` to the corresponding `Index` by mapping
   /// `base1.endIndex` to `base2.startIndex`.
-  @usableFromInline
+  @inlinable
   internal func convertIndex(_ i: Base1.Index) -> Index {
     i == base1.endIndex ? Index(second: base2.startIndex) : Index(first: i)
   }
@@ -157,7 +157,7 @@ extension Chain2: Collection where Base1: Collection, Base2: Collection {
       : offsetBackward(i, by: -n, limitedBy: limit)
   }
 
-  @usableFromInline
+  @inlinable
   internal func offsetForward(
     _ i: Index, by n: Int, limitedBy limit: Index
   ) -> Index? {
@@ -197,7 +197,7 @@ extension Chain2: Collection where Base1: Collection, Base2: Collection {
     }
   }
 
-  @usableFromInline
+  @inlinable
   internal func offsetBackward(
     _ i: Index, by n: Int, limitedBy limit: Index
   ) -> Index? {

Sources/Algorithms/Chunked.swift

@@ -27,7 +27,7 @@ public struct LazyChunked<Base: Collection, Subject> {
   @usableFromInline
   internal var firstUpperBound: Base.Index
 
-  @usableFromInline
+  @inlinable
   internal init(
     base: Base,
     projection: @escaping (Base.Element) -> Subject,
@@ -51,7 +51,7 @@ extension LazyChunked: LazyCollectionProtocol {
     @usableFromInline
     internal var baseRange: Range<Base.Index>
 
-    @usableFromInline
+    @inlinable
     internal init(_ baseRange: Range<Base.Index>) {
       self.baseRange = baseRange
     }
@@ -72,7 +72,7 @@ extension LazyChunked: LazyCollectionProtocol {
 
   /// Returns the index in the base collection of the end of the chunk starting
   /// at the given index.
-  @usableFromInline
+  @inlinable
   internal func endOfChunk(startingAt start: Base.Index) -> Base.Index {
     let subject = projection(base[start])
     return base[base.index(after: start)...]
@@ -112,7 +112,7 @@ extension LazyChunked: BidirectionalCollection
 {
   /// Returns the index in the base collection of the start of the chunk ending
   /// at the given index.
-  @usableFromInline
+  @inlinable
   internal func startOfChunk(endingAt end: Base.Index) -> Base.Index {
     let indexBeforeEnd = base.index(before: end)
 
@@ -174,7 +174,7 @@ extension Collection {
   /// predicate.
   ///
   /// - Complexity: O(*n*), where *n* is the length of this collection.
-  @usableFromInline
+  @inlinable
   internal func chunked<Subject>(
     on projection: (Element) throws -> Subject,
     by belongInSameGroup: (Subject, Subject) throws -> Bool
@@ -273,7 +273,7 @@ extension ChunkedByCount: Collection {
     @usableFromInline
     internal let baseRange: Range<Base.Index>
 
-    @usableFromInline
+    @inlinable
     internal init(_baseRange: Range<Base.Index>) {
       self.baseRange = _baseRange
     }
@@ -290,6 +290,7 @@ extension ChunkedByCount: Collection {
   }
 
   /// - Complexity: O(1)
+  @inlinable
   public subscript(i: Index) -> Element {
     precondition(i < endIndex, "Index out of range")
     return base[i.baseRange]
@@ -392,7 +393,7 @@ extension ChunkedByCount {
     return index
   }
 
-  @usableFromInline
+  @inlinable
   internal func offsetForward(
     _ i: Index, offsetBy distance: Int, limit: Index? = nil
   ) -> Index? {
@@ -406,8 +407,8 @@ extension ChunkedByCount {
   }
 
   // Convenience to compute offset backward base distance.
-  @inline(__always)
-  private func computeOffsetBackwardBaseDistance(
+  @inlinable
+  internal func computeOffsetBackwardBaseDistance(
     _ i: Index, _ distance: Int
   ) -> Int {
     if i == endIndex {
@@ -423,7 +424,7 @@ extension ChunkedByCount {
     return distance * chunkCount
   }
 
-  @usableFromInline
+  @inlinable
   internal func offsetBackward(
     _ i: Index, offsetBy distance: Int, limit: Index? = nil
   ) -> Index? {
@@ -438,8 +439,8 @@ extension ChunkedByCount {
   }
 
   // Helper to compute index(offsetBy:) index.
-  @inline(__always)
-  private func makeOffsetIndex(
+  @inlinable
+  internal func makeOffsetIndex(
     from i: Index, baseBound: Base.Index, distance: Int, baseDistance: Int,
     limit: Index?, by limitFn: (Base.Index, Base.Index) -> Bool
   ) -> Index? {

Sources/Algorithms/Combinations.swift

@@ -27,7 +27,7 @@ public struct Combinations<Base: Collection> {
   /// - Parameters:
   ///   - base: The collection to iterate over for combinations.
   ///   - k: The expected size of each combination.
-  @usableFromInline
+  @inlinable
   internal init(_ base: Base, k: Int) {
     self.init(base, kRange: k...k)
   }
@@ -37,7 +37,7 @@ public struct Combinations<Base: Collection> {
   /// - Parameters:
   ///   - base: The collection to iterate over for combinations.
   ///   - kRange: The range of accepted sizes of combinations.
-  @usableFromInline
+  @inlinable
   internal init<R: RangeExpression>(
     _ base: Base, kRange: R
   ) where R.Bound == Int {
@@ -89,14 +89,15 @@ extension Combinations: Sequence {
     internal var kRange: Range<Int>
 
     /// Whether or not iteration is finished (`kRange` is empty)
-    @usableFromInline
+    @inlinable
     internal var isFinished: Bool {
       return kRange.isEmpty
     }
 
     @usableFromInline
     internal var indexes: [Base.Index]
 
+    @inlinable
     internal init(_ combinations: Combinations) {
       self.base = combinations.base
       self.kRange = combinations.kRange ?? 0..<0
@@ -121,7 +122,7 @@ extension Combinations: Sequence {
     ///     [2, 3, 4] *
     ///     // Can't advance without needing to go past `base.endIndex`,
     ///     // so the iteration is finished.
-    @usableFromInline
+    @inlinable
     internal mutating func advance() {
       /// Advances `kRange` by incrementing its `lowerBound` until the range is
       /// empty, when iteration is finished.

Sources/Algorithms/Cycle.swift

@@ -14,7 +14,7 @@ public struct Cycle<Base: Collection> {
   /// The collection to repeat.
   public let base: Base
 
-  @usableFromInline
+  @inlinable
   internal init(base: Base) {
     self.base = base
   }
@@ -29,7 +29,7 @@ extension Cycle: Sequence {
     @usableFromInline
     var current: Base.Index
 
-    @usableFromInline
+    @inlinable
     internal init(base: Base) {
       self.base = base
       self.current = base.startIndex

Sources/Algorithms/Indexed.swift

@@ -18,7 +18,7 @@ public struct Indexed<Base: Collection> {
   /// The base collection.
   public let base: Base
 
-  @usableFromInline
+  @inlinable
   internal init(base: Base) {
     self.base = base
   }

Sources/Algorithms/Intersperse.swift

@@ -18,7 +18,7 @@ public struct Intersperse<Base: Sequence> {
   @usableFromInline
   internal let separator: Base.Element
 
-  @usableFromInline
+  @inlinable
   internal init(base: Base, separator: Base.Element) {
     self.base = base
     self.separator = separator
@@ -37,7 +37,7 @@ extension Intersperse: Sequence {
     @usableFromInline
     internal var state = State.start
 
-    @usableFromInline
+    @inlinable
     internal init(iterator: Base.Iterator, separator: Base.Element) {
       self.iterator = iterator
       self.separator = separator
@@ -89,6 +89,11 @@ extension Intersperse: Collection where Base: Collection {
     @usableFromInline
     internal let representation: Representation
 
+    @inlinable
+    init(representation: Representation) {
+      self.representation = representation
+    }
+
     @inlinable
     public static func < (lhs: Index, rhs: Index) -> Bool {
       switch (lhs.representation, rhs.representation) {
@@ -101,12 +106,12 @@ extension Intersperse: Collection where Base: Collection {
       }
     }
 
-    @usableFromInline
+    @inlinable
     static func element(_ index: Base.Index) -> Self {
       Self(representation: .element(index))
     }
 
-    @usableFromInline
+    @inlinable
     static func separator(next: Base.Index) -> Self {
       Self(representation: .separator(next: next))
     }

Sources/Algorithms/LazySplit.swift

@@ -34,7 +34,7 @@ public struct LazySplitSequence<Base: Sequence> {
   @usableFromInline
   internal let omittingEmptySubsequences: Bool
 
-  @usableFromInline
+  @inlinable
   internal init(
     base: Base,
     isSeparator: @escaping (Base.Element) -> Bool,
@@ -72,7 +72,7 @@ extension LazySplitSequence {
     @usableFromInline
     internal var sequenceLength = 0
 
-    @usableFromInline
+    @inlinable
     internal init(
       base: Base.Iterator,
       whereSeparator: @escaping (Base.Element) -> Bool,
@@ -360,7 +360,7 @@ public struct LazySplitCollection<Base: Collection> {
   @usableFromInline
   internal var _startIndex: Index
 
-  @usableFromInline
+  @inlinable
   internal init(
     base: Base,
     isSeparator: @escaping (Base.Element) -> Bool,
@@ -415,7 +415,7 @@ extension LazySplitCollection: LazyCollectionProtocol {
     @usableFromInline
     internal let splitCount: Int
 
-    @usableFromInline
+    @inlinable
     internal init(
       baseRange: Range<Base.Index>,
       sequenceLength: Int,
@@ -441,7 +441,7 @@ extension LazySplitCollection: LazyCollectionProtocol {
 
   /// Returns the index of the subsequence starting at or after the given base
   /// collection index.
-  @usableFromInline
+  @inlinable
   internal func indexForSubsequence(
     atOrAfter lowerBound: Base.Index,
     sequenceLength: Int,

Sources/Algorithms/Partition.swift

@@ -21,7 +21,7 @@ extension MutableCollection {
   /// - Complexity: O(*n* log *n*), where *n* is the number of elements.
   /// - Precondition:
   ///   `n == distance(from: range.lowerBound, to: range.upperBound)`
-  @usableFromInline
+  @inlinable
   internal mutating func stablePartition(
     count n: Int,
     subrange: Range<Index>,

Sources/Algorithms/Permutations.swift

@@ -28,7 +28,7 @@ public struct Permutations<Base: Collection> {
   ///   - base: The collection to iterate over for permutations
   ///   - k: The expected size of each permutation, or `nil` (default) to
   ///   iterate over all permutations of the same size as the base collection.
-  @usableFromInline
+  @inlinable
   internal init(_ base: Base, k: Int? = nil) {
     let kRange: ClosedRange<Int>?
     if let countToChoose = k {
@@ -45,7 +45,7 @@ public struct Permutations<Base: Collection> {
   ///   - base: The collection to iterate over for permutations.
   ///   - kRange: The range of accepted sizes of permutations, or `nil` to
   ///   iterate over all permutations of the same size as the base collection.
-  @usableFromInline
+  @inlinable
   internal init<R: RangeExpression>(
     _ base: Base, kRange: R?
   ) where R.Bound == Int {
@@ -84,15 +84,15 @@ extension Permutations: Sequence {
     internal var kRange: Range<Int>
 
     /// Whether or not iteration is finished (`kRange` is empty)
-    @usableFromInline
+    @inlinable
     internal var isFinished: Bool {
       return kRange.isEmpty
     }
 
     @usableFromInline
     internal var indexes: [Base.Index]
 
-    @usableFromInline
+    @inlinable
     internal init(_ permutations: Permutations) {
       self.base = permutations.base
       self.baseCount = permutations.baseCount
@@ -111,7 +111,7 @@ extension Permutations: Sequence {
     ///   is in ascending order.
     ///
     /// - Complexity: O(*n*), where *n* is the length of the collection.
-    @usableFromInline
+    @inlinable
     internal mutating func nextState() -> Bool {
       let countToChoose = self.kRange.lowerBound
       let edge = countToChoose - 1