natecook1000

func unzip2<
  S: SequenceType, T, U where S.Generator.Element == (T, U)
  >(x: S) -> (AnySequence<T>, AnySequence<U>) 
{
  return (AnySequence(x.lazy.map { $0.0 }), AnySequence(x.lazy.map { $0.1 }))
}

func unzip2<
  C: CollectionType, T, U where C.Generator.Element == (T, U), C.Index: RandomAccessIndexType
  >(x: C) -> (AnyRandomAccessCollection<T>, AnyRandomAccessCollection<U>) 

natecook1000

Expanded min/max algorithms

• Proposal: TBD
• Author(s): Nate Cook
• Status: Draft
• Review manager: TBD

Introduction

This proposal would expand on the min() and max() sequence methods to add methods that return the corresponding index for a collection, efficiently find the minimum and maximum elements or indices at the same time, and provide extension points for sorted collections to provide all these results more efficiently.

natecook1000

Build Swift first using utils/build-script -R, other settings will need different directories below. Add these lines to ~/.bashrc, call with run-test path/to/test:

LLVM_DIR="/path/to/Swift/llvm"
SWIFT_BUILD_DIR="/path/to/Swift/build/Ninja-ReleaseAssert/swift-macosx-x86_64"

run-validation-test() {
    $LLVM_DIR/utils/lit/lit.py -a --param swift_site_config=$SWIFT_BUILD_DIR/validation-test-macosx-x86_64/lit.site.cfg $1
}

natecook1000

natecook1000

#!/bin/sh

set -e

if [ -z "${CONFIGURATION}" ]; then
    CONFIGURATION=debug
fi

# Create the development toolchain.
rm -rf ~/public/swift-project/build/Ninja-ReleaseAssert/swift-dev.xctoolchain

natecook1000

import Darwin
import CoreFoundation

// A variable we can use with exit() to ensure that the optimizer
// doesn't remove code we want to time
var undead = 0 

// A filtered collection that can be more efficiently counted than the stock one.
struct LazyFilterBidirectionalCollection2<Base : BidirectionalCollection> : Collection {
  typealias Impl = LazyFilterBidirectionalCollection<Base>

natecook1000

import Foundation

public class CoRoutine<T> {
    private var index = 0
    private var sequence : [T]
    private var routine : (T)->()
    private let step : Int?
    private let deltaTime : TimeInterval?
    private(set) public var isCanceled : Bool = false
    private(set) public var isDone : Bool = false

natecook1000

Dictionary & Set Enhancements

• Proposal: SE-0000
• Author: Nate Cook
• Review Manager: TBD
• Status: Awaiting review

Introduction

This proposal comprises a variety of commonly (and less commonly) suggested improvements to the standard library's Dictionary type, from merging initializers to dictionary-specific filter and mapValues methods. The proposed additions to Dictionary, and the corresponding changes to Set, are detailed in the sections below.

natecook1000

// Additions to make the unsafe pointer APIs more consistent

extension UnsafePointer {
  func deallocate(capacity: Int) {
    UnsafeMutablePointer(mutating: self).deallocate(capacity: capacity)
  }
}

extension UnsafeBufferPointer {
  func deallocate() {

natecook1000

/// A sequence of weakly held elements.
///
/// Iterating over this sequence yields the elements that still exist at the
/// moment of iteration. Subsequent iterations may not yield the same elements,
/// as some elements may have been removed from memory.
public struct WeakSequence<Element: AnyObject> : Sequence {
  var _contents: [Box] = []
  
  /// A box for weakly holding a class instance.
  class Box {