655 lines
30 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2020 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
@_spi(Reflection) import Swift
@_implementationOnly import os
#endif
extension String {
@available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
public init(_ characters: Slice<AttributedString.CharacterView>) {
let range = Range(uncheckedBounds: (characters.startIndex, characters.endIndex))
self.init(_from: characters.base._guts.string, in: range._bstringRange)
}
#if true // FIXME: Make this public.
@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, *)
internal init(_characters: AttributedString.CharacterView) {
self.init(_from: _characters._guts.string, in: _characters._range._bstringRange)
}
#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(_from: _characters._guts.string, in: _characters._range._bstringRange)
}
#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 _BString
let result = NSMutableAttributedString(string: String(_from: 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.utf8Index(stringStart, offsetBy: run.length)
let utf16Length = attrStr._guts.string.utf16Distance(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]()
_forEachField(of: scope, options: [.ignoreUnknown]) { pointer, offset, type, kind -> Bool in
switch type {
case let attribute as any AttributedStringKey.Type:
result[attribute.name] = attribute
break
case let scope as any AttributeScope.Type:
result.merge(_loadAttributeTypes(from: scope), uniquingKeysWith: { current, new in new })
break
default: break
}
return true
}
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.characterIndex(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.utf16Offset(of: target.startIndex._value)
let utf16Start = str.utf16Offset(of: range.lowerBound._value)
let utf16Length = str.utf16Distance(
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: _BString
let _range: Range<_BString.Index>
init(_ string: _BString, _ range: Range<_BString.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.characterIndex(after: j)
return Index(_utf8Offset: k._utf8Offset)
}
}
}
extension _BString {
func index(from stringIndex: String.Index) -> Index? {
if stringIndex._canBeUTF8 {
let utf8Offset = stringIndex._utf8Offset
let utf16Delta = stringIndex._utf16Delta
guard utf16Delta <= 1 else { return nil }
let j = _BString.Index(_utf8Offset: utf8Offset, utf16TrailingSurrogate: utf16Delta > 0)
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.utf16Count else { return nil }
let j = utf16Index(at: 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 Index(
baseUTF8Offset: j._utf8BaseOffset,
rope: j._rope!,
chunk: String.Index(_utf8Offset: j._utf8ChunkOffset + 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
guard endOffset <= string.__guts.string.utf16Count else { return nil }
let start = string.__guts.string.utf16Index(at: range.location)
let end = string.__guts.string.utf16Index(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(_BString.Index(_utf8Offset: string.startIndex._utf8Offset)) }
var endIndex: Index { Index(_BString.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(_BString.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
}