milseman

extension String {
    public func _compareStringLinux(_ rhs: String) -> Int {
        // Fast lexigraphic comparison of (composed) pre-normalized prefixes
        var lhsCore = self._core
        var rhsCore = rhs._core
        let minCount = Swift.min(lhsCore.count, rhsCore.count)
        for idx in 0..<minCount {
            // Detect when pre-normalization ends: Quick check if next code unit might be combining
            if idx+1 < minCount && (lhsCore[idx+1] >= 0x300 || rhsCore[idx+1] >= 0x300) {

milseman

struct S1 {
  var stored: UInt?

  init(_ x: UInt) {
    if x > 42 {
      self.init(_big: x)
      return
    }
    self.stored = x // <--- error: 'self' used before 'self.init' call or assignment to 'self'
  }

milseman

protocol ESI {
  // Interpolate a segment
  mutating func addSegment<T>(_ t: T)

  // Interpolate a literal
  mutating func addLiteral(_ s: String)

  // Compiler will produce closure to pass to this init. Closure will consist
  // of calls to writeSegment and writeLiteral
  init(performingInterpolation: (inout Self) -> ())

milseman

Character Properties

• Proposal: TBD
• Authors: Michael Ilseman, Tony Allevato
• Review Manager: TBD
• Status: TBD
• Implementation: apple/swift#15880

Introduction

@allevato (a co-author here) proposed Add Unicode Properties to Unicode.Scalar, which exposes Unicode properties from the Unicode Character Database. These are Unicode expert/enthusiast oriented properties that give a finer granularity of control and answer highly-technical and specific Unicody enquiries.

milseman

let str1 = "a\u{1680}b"
let str2 = "a\u{0020}b"
print(str1) // "a b"
print(str2) // "a b"

milseman

print("start")

public var i = 0

// @inline(never)
// public func blackHole<T>(_ x: T) {
//   i += 1  
// }
@inline(never)

milseman

var i = 0
while i <= 0x4_0000 { 
  let size = malloc_size(malloc(i+1)) 
  print(" \(i+1) => \(size) (\(size - i))") 
  i = size 
}

64-bit MacOS:

milseman

extension String.Index {
    /// Creates a new index at the specified UTF-16 code unit offset
  ///
  /// - Parameter offset: An offset in UTF-16 code units.
  public init(offset: Int, within utf16: String.UTF16View) {
    let (start, end) = (utf16.startIndex, utf16.endIndex)
    guard offset >= 0,
          let idx = utf16.index(start, offsetBy: offset, limitedBy: end)
    else {
      self = end

milseman

precedencegroup RelativeOffsetPrecedence {
  higherThan: RangeFormationPrecedence
}

infix operator ++ : RelativeOffsetPrecedence
infix operator -- : RelativeOffsetPrecedence

extension Collection {
  internal func _clampedIndex(_ idx: Index, offsetBy offset: Int) -> Index {
    let limit = offset < 0 ? startIndex : endIndex

milseman

precedencegroup RelativeOffsetPrecedence {
  higherThan: RangeFormationPrecedence
}

infix operator --> : RelativeOffsetPrecedence
infix operator <-- : RelativeOffsetPrecedence
prefix operator -->
postfix operator <--

extension Collection {