Karoy Lorentey e9b2f68e8a
rdar://107778676 Stop vendoring the Collections package (#50)
* rdar://107778676 Stop vendoring the Collections package

* rdar://107778676 Fix test expectation

AttributedString.CharacterView needs to round all indices down to the
nearest Character boundary to avoid semantic issues with its
Collection conformance. This means that CharacterView slices can never
start or end in between Character boundaries.

* Remove a stray print statement
2023-04-25 13:44:02 -07:00

655 lines
30 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2020-2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#if FOUNDATION_FRAMEWORK
import Darwin
@_implementationOnly import ReflectionInternal
@_implementationOnly import os
@_implementationOnly @_spi(Unstable) import CollectionsInternal
#else
import _RopeModule
#endif
extension String {
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public init(_ characters: Slice<AttributedString.CharacterView>) {
self.init(characters._characters)
}
#if true // FIXME: Make this public.
@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
internal init(_characters: AttributedString.CharacterView) {
self.init(_characters._characters)
}
#else
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
@_alwaysEmitIntoClient
public init(_ characters: AttributedString.CharacterView) {
if #available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *) {
self.init(_characters: characters)
return
}
// Forward to the slice overload above, which somehow did end up shipping in
// the original AttributedString release.
self.init(characters[...])
}
@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
@usableFromInline
internal init(_characters: AttributedString.CharacterView) {
self.init(_characters._characters)
}
#endif
}
#if FOUNDATION_FRAMEWORK
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public protocol ObjectiveCConvertibleAttributedStringKey : AttributedStringKey {
associatedtype ObjectiveCValue : NSObject
static func objectiveCValue(for value: Value) throws -> ObjectiveCValue
static func value(for object: ObjectiveCValue) throws -> Value
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension ObjectiveCConvertibleAttributedStringKey where Value : RawRepresentable, Value.RawValue == Int, ObjectiveCValue == NSNumber {
static func objectiveCValue(for value: Value) throws -> ObjectiveCValue {
return NSNumber(value: value.rawValue)
}
static func value(for object: ObjectiveCValue) throws -> Value {
if let val = Value(rawValue: object.intValue) {
return val
}
throw CocoaError(.coderInvalidValue)
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension ObjectiveCConvertibleAttributedStringKey where Value : RawRepresentable, Value.RawValue == String, ObjectiveCValue == NSString {
static func objectiveCValue(for value: Value) throws -> ObjectiveCValue {
return value.rawValue as NSString
}
static func value(for object: ObjectiveCValue) throws -> Value {
if let val = Value(rawValue: object as String) {
return val
}
throw CocoaError(.coderInvalidValue)
}
}
internal struct _AttributeConversionOptions : OptionSet {
let rawValue: Int
// If an attribute's value(for: ObjectieCValue) or objectiveCValue(for: Value) function throws, ignore the error and drop the attribute
static let dropThrowingAttributes = Self(rawValue: 1 << 0)
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension AttributeContainer {
init(_ dictionary: [NSAttributedString.Key : Any]) {
var attributeKeyTypes = _loadDefaultAttributes()
// Passing .dropThrowingAttributes causes attributes that throw during conversion to be dropped, so it is safe to do try! here
try! self.init(dictionary, including: AttributeScopes.FoundationAttributes.self, attributeKeyTypes: &attributeKeyTypes, options: .dropThrowingAttributes)
}
init<S: AttributeScope>(_ dictionary: [NSAttributedString.Key : Any], including scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(dictionary, including: S.self)
}
init<S: AttributeScope>(_ dictionary: [NSAttributedString.Key : Any], including scope: S.Type) throws {
var attributeKeyTypes = [String : any AttributedStringKey.Type]()
try self.init(dictionary, including: scope, attributeKeyTypes: &attributeKeyTypes)
}
fileprivate init<S: AttributeScope>(_ dictionary: [NSAttributedString.Key : Any], including scope: S.Type, attributeKeyTypes: inout [String : any AttributedStringKey.Type], options: _AttributeConversionOptions = []) throws {
storage = .init()
for (key, value) in dictionary {
if let type = attributeKeyTypes[key.rawValue] ?? S.attributeKeyType(matching: key.rawValue) {
attributeKeyTypes[key.rawValue] = type
func project<K: AttributedStringKey>(_: K.Type) throws {
storage[K.self] = try K._convertFromObjectiveCValue(value as AnyObject)
}
do {
try project(type)
} catch let conversionError {
if !options.contains(.dropThrowingAttributes) {
throw conversionError
}
}
} // else, attribute is not in provided scope, so drop it
}
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension Dictionary where Key == NSAttributedString.Key, Value == Any {
init(_ container: AttributeContainer) {
var attributeKeyTypes = _loadDefaultAttributes()
// Passing .dropThrowingAttributes causes attributes that throw during conversion to be dropped, so it is safe to do try! here
try! self.init(container, including: AttributeScopes.FoundationAttributes.self, attributeKeyTypes: &attributeKeyTypes, options: .dropThrowingAttributes)
}
init<S: AttributeScope>(_ container: AttributeContainer, including scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(container, including: S.self)
}
init<S: AttributeScope>(_ container: AttributeContainer, including scope: S.Type) throws {
var attributeKeyTypes = [String : any AttributedStringKey.Type]()
try self.init(container, including: scope, attributeKeyTypes: &attributeKeyTypes)
}
// These includingOnly SPI initializers were provided originally when conversion boxed attributes outside of the given scope as an AnyObject
// After rdar://80201634, these SPI initializers have the same behavior as the API initializers
@_spi(AttributedString)
init<S: AttributeScope>(_ container: AttributeContainer, includingOnly scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(container, including: S.self)
}
@_spi(AttributedString)
init<S: AttributeScope>(_ container: AttributeContainer, includingOnly scope: S.Type) throws {
try self.init(container, including: S.self)
}
fileprivate init<S: AttributeScope>(_ container: AttributeContainer, including scope: S.Type, attributeKeyTypes: inout [String : any AttributedStringKey.Type], options: _AttributeConversionOptions = []) throws {
self.init()
for key in container.storage.keys {
if let type = attributeKeyTypes[key] ?? S.attributeKeyType(matching: key) {
attributeKeyTypes[key] = type
func project<K: AttributedStringKey>(_: K.Type) throws {
self[NSAttributedString.Key(rawValue: key)] = try K._convertToObjectiveCValue(container.storage[K.self]!)
}
do {
try project(type)
} catch let conversionError {
if !options.contains(.dropThrowingAttributes) {
throw conversionError
}
}
}
}
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension NSAttributedString {
convenience init(_ attrStr: AttributedString) {
// Passing .dropThrowingAttributes causes attributes that throw during conversion to be dropped, so it is safe to do try! here
try! self.init(attrStr, scope: AttributeScopes.FoundationAttributes.self, otherAttributeTypes: _loadDefaultAttributes(), options: .dropThrowingAttributes)
}
convenience init<S: AttributeScope>(_ attrStr: AttributedString, including scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(attrStr, scope: S.self)
}
convenience init<S: AttributeScope>(_ attrStr: AttributedString, including scope: S.Type) throws {
try self.init(attrStr, scope: scope)
}
@_spi(AttributedString)
convenience init<S: AttributeScope>(_ attrStr: AttributedString, includingOnly scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(attrStr, scope: S.self)
}
@_spi(AttributedString)
convenience init<S: AttributeScope>(_ attrStr: AttributedString, includingOnly scope: S.Type) throws {
try self.init(attrStr, scope: scope)
}
internal convenience init<S: AttributeScope>(
_ attrStr: AttributedString,
scope: S.Type,
otherAttributeTypes: [String : any AttributedStringKey.Type] = [:],
options: _AttributeConversionOptions = []
) throws {
// FIXME: Consider making an NSString subclass backed by a BigString
let result = NSMutableAttributedString(string: String(attrStr._guts.string))
var attributeKeyTypes: [String : any AttributedStringKey.Type] = otherAttributeTypes
// Iterate through each run of the source
var nsStartIndex = 0
var stringStart = attrStr._guts.string.startIndex
for run in attrStr._guts.runs {
let stringEnd = attrStr._guts.string.utf8.index(stringStart, offsetBy: run.length)
let utf16Length = attrStr._guts.string.utf16.distance(from: stringStart, to: stringEnd)
let range = NSRange(location: nsStartIndex, length: utf16Length)
let attributes = try Dictionary(AttributeContainer(run.attributes), including: scope, attributeKeyTypes: &attributeKeyTypes, options: options)
result.setAttributes(attributes, range: range)
nsStartIndex += utf16Length
stringStart = stringEnd
}
self.init(attributedString: result)
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public extension AttributedString {
init(_ nsStr: NSAttributedString) {
// Passing .dropThrowingAttributes causes attributes that throw during conversion to be dropped, so it is safe to do try! here
try! self.init(nsStr, scope: AttributeScopes.FoundationAttributes.self, otherAttributeTypes: _loadDefaultAttributes(), options: .dropThrowingAttributes)
}
init<S: AttributeScope>(_ nsStr: NSAttributedString, including scope: KeyPath<AttributeScopes, S.Type>) throws {
try self.init(nsStr, scope: S.self)
}
init<S: AttributeScope>(_ nsStr: NSAttributedString, including scope: S.Type) throws {
try self.init(nsStr, scope: S.self)
}
private init<S: AttributeScope>(_ nsStr: NSAttributedString, scope: S.Type, otherAttributeTypes: [String : any AttributedStringKey.Type] = [:], options: _AttributeConversionOptions = []) throws {
var string = nsStr.string
// Eagerly bridge to a native string since AttributedString will do this anyways and this guarantees string's contents are well-formed (no unpaired surrogate characters)
string.makeContiguousUTF8()
var runs: [_InternalRun] = []
var attributeKeyTypes: [String : any AttributedStringKey.Type] = otherAttributeTypes
var conversionError: Error?
var endOfLastRange = string.utf16.startIndex
var hasConstrainedAttributes = false
// Enumerated ranges are guaranteed to be contiguous and have non-zero length
nsStr.enumerateAttributes(in: NSMakeRange(0, nsStr.length), options: []) { (nsAttrs, range, stop) in
let container: AttributeContainer
do {
container = try AttributeContainer(nsAttrs, including: scope, attributeKeyTypes: &attributeKeyTypes, options: options)
} catch {
conversionError = error
stop.pointee = true
return
}
var startOfCurrentRun = endOfLastRange
var endOfCurrentRun = string.utf16.index(startOfCurrentRun, offsetBy: range.length)
endOfLastRange = endOfCurrentRun
// If the run ends in the middle of a surrogate pair, extend it to the full range of the pair
if UTF16.isLeadSurrogate(string.utf16[string.utf16.index(before: endOfCurrentRun)]) {
endOfCurrentRun = string.utf16.index(after: endOfCurrentRun)
}
// If the run begins in the middle of a surrogate pair, compress it forward to exclude the initial low character
// Note: this can result in a zero-length run which is guarded against below
if UTF16.isTrailSurrogate(string.utf16[startOfCurrentRun]) {
startOfCurrentRun = string.utf16.index(after: startOfCurrentRun)
}
let runLength = string.utf8.distance(from: startOfCurrentRun, to: endOfCurrentRun)
guard runLength > 0 else { return }
let attrStorage = container.storage
if let previous = runs.last, previous.attributes == attrStorage {
runs[runs.endIndex - 1].length += runLength
} else {
runs.append(_InternalRun(length: runLength, attributes: attrStorage))
if !hasConstrainedAttributes {
hasConstrainedAttributes = attrStorage.hasConstrainedAttributes
}
}
}
if let error = conversionError {
throw error
}
self = AttributedString(Guts(string: string, runs: runs))
if hasConstrainedAttributes {
self._guts.adjustConstrainedAttributesForUntrustedRuns()
}
}
}
internal func _loadDefaultAttributes() -> [String : any AttributedStringKey.Type] {
#if !targetEnvironment(macCatalyst)
// AppKit scope on macOS
let macOSSymbol = ("$s10Foundation15AttributeScopesO6AppKitE0dE10AttributesVN", "/usr/lib/swift/libswiftAppKit.dylib")
#else
// UIKit scope on macOS
let macOSSymbol = ("$s10Foundation15AttributeScopesO5UIKitE0D10AttributesVN", "/System/iOSSupport/System/Library/Frameworks/UIKit.framework/UIKit")
#endif
let loadedScopes = [
macOSSymbol,
// UIKit scope on non-macOS
("$s10Foundation15AttributeScopesO5UIKitE0D10AttributesVN", "/System/Library/Frameworks/UIKit.framework/UIKit"),
// SwiftUI scope
("$s10Foundation15AttributeScopesO7SwiftUIE0D12UIAttributesVN", "/System/Library/Frameworks/SwiftUI.framework/SwiftUI"),
// Accessibility scope
("$s10Foundation15AttributeScopesO13AccessibilityE0D10AttributesVN", "/System/Library/Frameworks/Accessibility.framework/Accessibility")
].compactMap {
_loadScopeAttributes(forSymbol: $0.0, from: $0.1)
}
return loadedScopes.reduce([:]) { result, item in
result.merging(item) { current, new in new }
}
}
fileprivate struct LoadedScopeCache : Sendable {
var cache : [String : [String : any AttributedStringKey.Type]]
}
fileprivate let _loadedScopeCacheLock = OSAllocatedUnfairLock(initialState: LoadedScopeCache(cache: .init()))
fileprivate func _loadScopeAttributes(forSymbol symbol: String, from path: String) -> [String : any AttributedStringKey.Type]? {
return _loadedScopeCacheLock.withLock { cache in
if let cachedResult = cache.cache[symbol] {
return cachedResult
}
guard let handle = dlopen(path, RTLD_NOLOAD) else {
return nil
}
guard let symbolPointer = dlsym(handle, symbol) else {
return nil
}
guard let scopeType = unsafeBitCast(symbolPointer, to: Any.Type.self) as? any AttributeScope.Type else {
return nil
}
let attributeTypes = _loadAttributeTypes(from: scopeType)
cache.cache[symbol] = attributeTypes
return attributeTypes
}
}
fileprivate func _loadAttributeTypes<S: AttributeScope>(from scope: S.Type) -> [String : any AttributedStringKey.Type] {
var result = [String : any AttributedStringKey.Type]()
for field in Type(scope).fields {
switch field.type.swiftType {
case let attribute as any AttributedStringKey.Type:
result[attribute.name] = attribute
case let scope as any AttributeScope.Type:
result.merge(_loadAttributeTypes(from: scope), uniquingKeysWith: { current, new in new })
default: break
}
}
return result
}
#endif // FOUNDATION_FRAMEWORK
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
extension String.Index {
// FIXME: Converting indices between different collection types does not make sense.
// FIXME: (Indices are meaningless without the collection value to which they belong,
// FIXME: and this entry point is not given that.)
// FIXME: This API ought to be deprecated, with clients migrating to e.g. using UTF-8 offsets.
public init?<S: StringProtocol>(_ sourcePosition: AttributedString.Index, within target: S) {
let utf8Offset = sourcePosition._value.utf8Offset
let isTrailingSurrogate = sourcePosition._value._isUTF16TrailingSurrogate
let i = String.Index(_utf8Offset: utf8Offset, utf16TrailingSurrogate: isTrailingSurrogate)
self.init(i, within: target)
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
extension AttributedString.Index {
// FIXME: Converting indices between different collection types does not make sense.
// FIXME: (Indices are meaningless without the collection value to which they belong,
// FIXME: and this entry point is not given that.)
// FIXME: This API ought to be deprecated, with clients migrating to e.g. using UTF-8 offsets.
public init?<S: AttributedStringProtocol>(_ sourcePosition: String.Index, within target: S) {
guard
let i = target.__guts.string.index(from: sourcePosition),
i >= target.startIndex._value,
i <= target.endIndex._value
else {
return nil
}
let j = target.__guts.string.index(roundingDown: i)
guard j == i else { return nil }
self.init(j)
}
}
#if FOUNDATION_FRAMEWORK
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
extension NSRange {
public init<R: RangeExpression, S: AttributedStringProtocol>(
_ region: R,
in target: S
) where R.Bound == AttributedString.Index {
let range = region.relative(to: target.characters)
precondition(
range.lowerBound >= target.startIndex && range.upperBound <= target.endIndex,
"Range out of bounds")
let str = target.__guts.string
let utf16Base = str.utf16.distance(from: str.startIndex, to: target.startIndex._value)
let utf16Start = str.utf16.distance(from: str.startIndex, to: range.lowerBound._value)
let utf16Length = str.utf16.distance(
from: range.lowerBound._value,
to: range.upperBound._value)
self.init(location: utf16Start - utf16Base, length: utf16Length)
}
@available(macOS 13, iOS 16, tvOS 16, watchOS 9, *)
public init?<S: StringProtocol>(_ markdownSourcePosition: AttributedString.MarkdownSourcePosition, in target: S) {
let startOffsets: AttributedString.MarkdownSourcePosition.Offsets
let endOffsets: AttributedString.MarkdownSourcePosition.Offsets
if let start = markdownSourcePosition.startOffsets, let end = markdownSourcePosition.endOffsets {
startOffsets = start
endOffsets = end
} else {
guard let offsets = markdownSourcePosition.calculateOffsets(within: target) else {
self.init(location: NSNotFound, length: NSNotFound)
return
}
startOffsets = offsets.start
endOffsets = offsets.end
}
// Since bounds are inclusive, we need to advance to the next UTF-16 scalar
// If doing so will leave a hanging high surrogate value (i.e., the UTF-8 offset was within a code point), then don't advance
var actualEndUTF16 = startOffsets.utf16
if endOffsets.utf8 + 1 == endOffsets.utf8NextCodePoint {
actualEndUTF16 += endOffsets.utf16CurrentCodePointLength
}
self.init(location: startOffsets.utf16, length: actualEndUTF16 - startOffsets.utf16)
}
}
#endif // FOUNDATION_FRAMEWORK
extension AttributedString {
/// A dummy collection type whose only purpose is to facilitate a `RangeExpression.relative(to:)`
/// call that takes a range expression with string indices but needs to work on an
/// attributed string.
internal struct _IndexConverterFromString: Collection {
typealias Index = String.Index
typealias Element = Index
let _string: BigString
let _range: Range<BigString.Index>
init(_ string: BigString, _ range: Range<BigString.Index>) {
self._string = string
self._range = range
}
subscript(position: String.Index) -> String.Index { position }
var startIndex: String.Index { Index(_utf8Offset: _range.lowerBound.utf8Offset) }
var endIndex: String.Index { Index(_utf8Offset: _range.upperBound.utf8Offset) }
func index(after i: String.Index) -> Index {
guard let j = _string.index(from: i) else {
preconditionFailure("Index out of bounds")
}
let k = _string.index(after: j)
return Index(_utf8Offset: k.utf8Offset)
}
}
}
extension BigString {
func index(from stringIndex: String.Index) -> Index? {
if stringIndex._canBeUTF8 {
let utf8Offset = stringIndex._utf8Offset
// Note: ideally we should also check that the result actually addresses a
// trailing surrogate, when this flag is true.
let utf16TrailingSurrogate = stringIndex._isUTF16TrailingSurrogate
let j = BigString.Index(
_utf8Offset: utf8Offset, utf16TrailingSurrogate: utf16TrailingSurrogate)
guard j <= endIndex else { return nil }
// Note: if utf16Delta > 0, ideally we should also check that the result
// addresses a trailing surrogate.
return j
}
let utf16Offset = stringIndex._abi_encodedOffset
let utf8Delta = stringIndex._abi_transcodedOffset
guard utf16Offset <= self.utf16.count else { return nil }
let j = self.utf16.index(self.startIndex, offsetBy: utf16Offset)
guard utf8Delta > 0 else { return j }
// Note: if utf8Delta > 0, ideally we should also check that the result
// addresses a scalar that actually does have that many continuation bytes.
return self.utf8.index(j, offsetBy: utf8Delta)
}
func stringIndex(from index: Index) -> String.Index? {
String.Index(
_utf8Offset: index.utf8Offset,
utf16TrailingSurrogate: index._isUTF16TrailingSurrogate)
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
extension Range where Bound == AttributedString.Index {
#if FOUNDATION_FRAMEWORK
public init?<S: AttributedStringProtocol>(_ range: NSRange, in string: S) {
// FIXME: This can return indices addressing trailing surrogates, which isn't a thing
// FIXME: AttributedString is normally prepared to handle.
// FIXME: Consider rounding everything down to the nearest scalar boundary.
guard range.location != NSNotFound else { return nil }
guard range.location >= 0, range.length >= 0 else { return nil }
let endOffset = range.location + range.length
let bstr = string.__guts.string
guard endOffset <= bstr.utf16.count else { return nil }
let start = bstr.utf16.index(bstr.startIndex, offsetBy: range.location)
let end = bstr.utf16.index(start, offsetBy: range.length)
guard start >= string.startIndex._value, end <= string.endIndex._value else { return nil }
self.init(uncheckedBounds: (.init(start), .init(end)))
}
#endif // FOUNDATION_FRAMEWORK
// FIXME: Converting indices between different collection types does not make sense.
// FIXME: (Indices are meaningless without the collection value to which they belong,
// FIXME: and this entry point is not given that.)
// FIXME: This API ought to be deprecated, with clients migrating to using UTF-8 offsets.
public init?<R: RangeExpression, S: AttributedStringProtocol>(
_ region: R,
in attributedString: S
) where R.Bound == String.Index {
if let range = region as? Range<String.Index> {
self.init(_range: range, in: attributedString)
return
}
// This is a frustrating API to implement -- we need to convert String indices to
// AttributedString indices, but the only way for us to access the actual indices is to
// go through `RangeExpression.relative(to:)`, which requires a collection value with a
// matching index type. So we need to construct a dummy collection type for just that.
let dummy = AttributedString._IndexConverterFromString(
attributedString.__guts.string,
attributedString.startIndex._value ..< attributedString.endIndex._value)
let range = region.relative(to: dummy)
self.init(_range: range, in: attributedString)
}
// The FIXME above also applies to this internal initializer.
internal init?(
_range: Range<String.Index>,
in attributedString: some AttributedStringProtocol
) {
guard let lower = attributedString.__guts.string.index(from: _range.lowerBound),
let upper = attributedString.__guts.string.index(from: _range.upperBound),
lower >= attributedString.startIndex._value,
upper <= attributedString.endIndex._value
else {
return nil
}
self.init(uncheckedBounds: (.init(lower), .init(upper)))
}
}
extension AttributedString {
/// A dummy collection type whose only purpose is to facilitate a `RangeExpression.relative(to:)`
/// call that takes a range expression with attributed string indices but needs to work on a
/// regular string.
internal struct _IndexConverterFromAttributedString: Collection {
typealias Index = AttributedString.Index
typealias Element = Index
let string: Substring
init(_ string: Substring) { self.string = string }
subscript(position: Index) -> Index { position }
var startIndex: Index { Index(BigString.Index(_utf8Offset: string.startIndex._utf8Offset)) }
var endIndex: Index { Index(BigString.Index(_utf8Offset: string.endIndex._utf8Offset)) }
func index(after i: Index) -> Index {
let j = String.Index(_utf8Offset: i._value.utf8Offset)
let k = string.index(after: j)
return Index(BigString.Index(_utf8Offset: k._utf8Offset))
}
}
}
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
extension Range where Bound == String.Index {
// FIXME: Converting indices between different collection types does not make sense.
// FIXME: (Indices are meaningless without the collection value to which they belong,
// FIXME: and this entry point is not given that.)
// FIXME: This API ought to be deprecated, with clients migrating to using UTF-8 offsets.
public init?<R: RangeExpression, S: StringProtocol>(
_ region: R,
in string: S
) where R.Bound == AttributedString.Index {
if let range = region as? Range<AttributedString.Index> {
self.init(_range: range, in: Substring(string))
return
}
let str = Substring(string)
let dummy = AttributedString._IndexConverterFromAttributedString(str)
let range = region.relative(to: dummy)
self.init(_range: range, in: str)
}
// The FIXME above also applies to this internal initializer.
internal init?(
_range: Range<AttributedString.Index>,
in string: Substring
) {
// Note: Attributed string indices are usually going to get implicitly round down to
// (at least) the nearest scalar boundary, but NSRange conversions can still generate
// indices addressing trailing surrogates, and we want to preserve those here.
let start = String.Index(
_utf8Offset: _range.lowerBound._value.utf8Offset,
utf16TrailingSurrogate: _range.lowerBound._value._isUTF16TrailingSurrogate)
let end = String.Index(
_utf8Offset: _range.upperBound._value.utf8Offset,
utf16TrailingSurrogate: _range.upperBound._value._isUTF16TrailingSurrogate)
guard string.startIndex <= start, end <= string.endIndex else { return nil }
self.init(uncheckedBounds: (start, end))
}
#if FOUNDATION_FRAMEWORK
// TODO: Support AttributedString markdown in FoundationPreview
@available(macOS 13, iOS 16, tvOS 16, watchOS 9, *)
public init?<S: StringProtocol>(_ markdownSourcePosition: AttributedString.MarkdownSourcePosition, in target: S) {
if let start = markdownSourcePosition.startOffsets, let end = markdownSourcePosition.endOffsets {
self = target.utf8.index(target.startIndex, offsetBy: start.utf8) ..< target.utf8.index(target.startIndex, offsetBy: end.utf8 + 1)
} else {
guard let offsets = markdownSourcePosition.calculateOffsets(within: target) else {
return nil
}
self = target.utf8.index(target.startIndex, offsetBy: offsets.start.utf8) ..< target.utf8.index(target.startIndex, offsetBy: offsets.end.utf8 + 1)
}
}
#endif // FOUNDATION_FRAMEWORK
}