diff --git a/benchmark/single-source/StringTests.swift b/benchmark/single-source/StringTests.swift index bcc43a263377..579ac6f3d3ce 100644 --- a/benchmark/single-source/StringTests.swift +++ b/benchmark/single-source/StringTests.swift @@ -49,6 +49,14 @@ public var benchmarks: [BenchmarkInfo] { runFunction: run_iterateWords, tags: [.validation, .String])) } + + if #available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, visionOS 9999, *) { + result.append( + BenchmarkInfo( + name: "StringIdentical", + runFunction: run_StringIdentical, + tags: [.validation, .api, .String])) + } return result } @@ -1676,3 +1684,14 @@ public func run_iterateWords(_ n: Int) { blackHole(swiftOrgHTML._words) } } + +@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, visionOS 9999, *) +public func run_StringIdentical(_ n: Int) { + let str1 = "The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog. " + let str2 = str1 + for _ in 0 ..< n { + for _ in 0 ..< 100_000 { + check(str1.isTriviallyIdentical(to: str2)) + } + } +} diff --git a/benchmark/single-source/SubstringTest.swift b/benchmark/single-source/SubstringTest.swift index 71ef0c774f26..a7652ff1064b 100644 --- a/benchmark/single-source/SubstringTest.swift +++ b/benchmark/single-source/SubstringTest.swift @@ -12,25 +12,34 @@ import TestsUtils -public let benchmarks = [ - BenchmarkInfo(name: "EqualStringSubstring", runFunction: run_EqualStringSubstring, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "EqualSubstringString", runFunction: run_EqualSubstringString, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "EqualSubstringSubstring", runFunction: run_EqualSubstringSubstring, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "EqualSubstringSubstringGenericEquatable", runFunction: run_EqualSubstringSubstringGenericEquatable, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringRemoveFirst1", runFunction: run_SubstringRemoveFirst1, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringRemoveLast1", runFunction: run_SubstringRemoveLast1, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "LessSubstringSubstring", runFunction: run_LessSubstringSubstring, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "LessSubstringSubstringGenericComparable", runFunction: run_LessSubstringSubstringGenericComparable, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "StringFromLongWholeSubstring", runFunction: run_StringFromLongWholeSubstring, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "StringFromLongWholeSubstringGeneric", runFunction: run_StringFromLongWholeSubstringGeneric, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringComparable", runFunction: run_SubstringComparable, tags: [.validation, .api, .String], - setUpFunction: { blackHole(_comparison) }), - BenchmarkInfo(name: "SubstringEqualString", runFunction: run_SubstringEqualString, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringEquatable", runFunction: run_SubstringEquatable, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringFromLongString2", runFunction: run_SubstringFromLongString, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringFromLongStringGeneric2", runFunction: run_SubstringFromLongStringGeneric, tags: [.validation, .api, .String]), - BenchmarkInfo(name: "SubstringTrimmingASCIIWhitespace", runFunction: run_SubstringTrimmingASCIIWhitespace, tags: [.validation, .api, .String]), -] +public var benchmarks: [BenchmarkInfo] { + var result = [ + BenchmarkInfo(name: "EqualStringSubstring", runFunction: run_EqualStringSubstring, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "EqualSubstringString", runFunction: run_EqualSubstringString, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "EqualSubstringSubstring", runFunction: run_EqualSubstringSubstring, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "EqualSubstringSubstringGenericEquatable", runFunction: run_EqualSubstringSubstringGenericEquatable, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringRemoveFirst1", runFunction: run_SubstringRemoveFirst1, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringRemoveLast1", runFunction: run_SubstringRemoveLast1, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "LessSubstringSubstring", runFunction: run_LessSubstringSubstring, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "LessSubstringSubstringGenericComparable", runFunction: run_LessSubstringSubstringGenericComparable, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "StringFromLongWholeSubstring", runFunction: run_StringFromLongWholeSubstring, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "StringFromLongWholeSubstringGeneric", runFunction: run_StringFromLongWholeSubstringGeneric, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringComparable", runFunction: run_SubstringComparable, tags: [.validation, .api, .String], + setUpFunction: { blackHole(_comparison) }), + BenchmarkInfo(name: "SubstringEqualString", runFunction: run_SubstringEqualString, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringEquatable", runFunction: run_SubstringEquatable, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringFromLongString2", runFunction: run_SubstringFromLongString, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringFromLongStringGeneric2", runFunction: run_SubstringFromLongStringGeneric, tags: [.validation, .api, .String]), + BenchmarkInfo(name: "SubstringTrimmingASCIIWhitespace", runFunction: run_SubstringTrimmingASCIIWhitespace, tags: [.validation, .api, .String]), + ] + + if #available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, visionOS 9999, *) { + result.append( + BenchmarkInfo(name: "SubstringIdentical", runFunction: run_SubstringIdentical, tags: [.validation, .String]), + ) + } + return result +} // A string that doesn't fit in small string storage and doesn't fit in Latin-1 let longWide = "fὢasὢodὢijὢadὢolὢsjὢalὢsdὢjlὢasὢdfὢijὢliὢsdὢjøὢslὢdiὢalὢiὢ" @@ -332,3 +341,12 @@ public func run _LessSubstringSubstringGenericStringProtocol(_ n: Int) { } } */ + +@inline(never) +@available(macOS 9999, iOS 9999, tvOS 9999, watchOS 9999, visionOS 9999, *) +public func run_SubstringIdentical(_ n: Int) { + let (a, b) = (ss1, ss1) + for _ in 1...n*500 { + blackHole(a.isTriviallyIdentical(to: b)) + } +} diff --git a/stdlib/public/core/String.swift b/stdlib/public/core/String.swift index e6715e91cc6e..884357639a35 100644 --- a/stdlib/public/core/String.swift +++ b/stdlib/public/core/String.swift @@ -1112,4 +1112,42 @@ extension String { } } - +extension String { + /// Returns a boolean value indicating whether this string is identical to + /// `other`. + /// + /// Two string values are identical if there is no way to distinguish between + /// them. + /// + /// For any values `a`, `b`, and `c`: + /// + /// - `a.isTriviallyIdentical(to: a)` is always `true`. (Reflexivity) + /// - `a.isTriviallyIdentical(to: b)` implies `b.isTriviallyIdentical(to: a)`. + /// (Symmetry) + /// - If `a.isTriviallyIdentical(to: b)` and `b.isTriviallyIdentical(to: c)` + /// are both `true`, then `a.isTriviallyIdentical(to: c)` is also `true`. + /// (Transitivity) + /// - `a.isTriviallyIdentical(b)` implies `a == b` + /// - `a == b` does not imply `a.isTriviallyIdentical(b)` + /// + /// Values produced by copying the same value, with no intervening mutations, + /// will compare identical: + /// + /// ```swift + /// let d = c + /// print(c.isTriviallyIdentical(to: d)) + /// // Prints true + /// ``` + /// + /// Comparing strings this way includes comparing (normally) hidden + /// implementation details such as the memory location of any underlying + /// string storage object. Therefore, identical strings are guaranteed to + /// compare equal with `==`, but not all equal strings are considered + /// identical. + /// + /// - Complexity: O(1) + @available(SwiftStdlib 6.3, *) + public func isTriviallyIdentical(to other: Self) -> Bool { + self._guts.rawBits == other._guts.rawBits + } +} diff --git a/stdlib/public/core/Substring.swift b/stdlib/public/core/Substring.swift index e4e91b6a02a4..42e020197b8b 100644 --- a/stdlib/public/core/Substring.swift +++ b/stdlib/public/core/Substring.swift @@ -1385,3 +1385,44 @@ extension Substring { return Substring(_unchecked: Slice(base: base, bounds: r)) } } + +extension Substring { + /// Returns a boolean value indicating whether this substring is identical to + /// `other`. + /// + /// Two substring values are identical if there is no way to distinguish + /// between them. + /// + /// For any values `a`, `b`, and `c`: + /// + /// - `a.isTriviallyIdentical(to: a)` is always `true`. (Reflexivity) + /// - `a.isTriviallyIdentical(to: b)` implies `b.isTriviallyIdentical(to: a)`. + /// (Symmetry) + /// - If `a.isTriviallyIdentical(to: b)` and `b.isTriviallyIdentical(to: c)` + /// are both `true`, then `a.isTriviallyIdentical(to: c)` is also `true`. + /// (Transitivity) + /// - `a.isTriviallyIdentical(b)` implies `a == b` + /// - `a == b` does not imply `a.isTriviallyIdentical(b)` + /// + /// Values produced by copying the same value, with no intervening mutations, + /// will compare identical: + /// + /// ```swift + /// let d = c + /// print(c.isTriviallyIdentical(to: d)) + /// // Prints true + /// ``` + /// + /// Comparing substrings this way includes comparing (normally) hidden + /// implementation details such as the memory location of any underlying + /// substring storage object. Therefore, identical substrings are guaranteed + /// to compare equal with `==`, but not all equal substrings are considered + /// identical. + /// + /// - Complexity: O(1) + @available(SwiftStdlib 6.3, *) + public func isTriviallyIdentical(to other: Self) -> Bool { + self._wholeGuts.rawBits == other._wholeGuts.rawBits && + self._offsetRange == other._offsetRange + } +} diff --git a/test/stdlib/StringAPI.swift b/test/stdlib/StringAPI.swift index fb33db9b53ee..bb3efc429221 100644 --- a/test/stdlib/StringAPI.swift +++ b/test/stdlib/StringAPI.swift @@ -533,4 +533,62 @@ StringTests.test("hasPrefix/hasSuffix vs Character boundaries") { expectFalse(s2.hasSuffix("\n")) } +StringTests.test("isTriviallyIdentical(to:) small ascii") +.skip(.custom( + { if #available(SwiftStdlib 6.3, *) { false } else { true } }, + reason: "Requires Swift 6.3's standard library" +)) +.code { + guard #available(SwiftStdlib 6.3, *) else { return } + + let a = "Hello" + let b = "Hello" + + precondition(a == b) + + expectTrue(a.isTriviallyIdentical(to: a)) + expectTrue(b.isTriviallyIdentical(to: b)) + expectTrue(a.isTriviallyIdentical(to: b)) // Both small ASCII strings + expectTrue(b.isTriviallyIdentical(to: a)) +} + +StringTests.test("isTriviallyIdentical(to:) small unicode") +.skip(.custom( + { if #available(SwiftStdlib 6.3, *) { false } else { true } }, + reason: "Requires Swift 6.3's standard library" +)) +.code { + guard #available(SwiftStdlib 6.3, *) else { return } + + let a = "Cafe\u{301}" + let b = "Cafe\u{301}" + let c = "Café" + + precondition(a == b) + precondition(b == c) + + expectTrue(a.isTriviallyIdentical(to: b)) + expectTrue(b.isTriviallyIdentical(to: a)) + expectFalse(a.isTriviallyIdentical(to: c)) + expectFalse(b.isTriviallyIdentical(to: c)) +} + +StringTests.test("isTriviallyIdentical(to:) large ascii") +.skip(.custom( + { if #available(SwiftStdlib 6.3, *) { false } else { true } }, + reason: "Requires Swift 6.3's standard library" +)) +.code { + guard #available(SwiftStdlib 6.3, *) else { return } + + let a = String(repeating: "foo", count: 1000) + let b = String(repeating: "foo", count: 1000) + + precondition(a == b) + + expectFalse(a.isTriviallyIdentical(to: b)) // Two large, distinct native strings + expectTrue(a.isTriviallyIdentical(to: a)) + expectTrue(b.isTriviallyIdentical(to: b)) +} + runAllTests() diff --git a/test/stdlib/subString.swift b/test/stdlib/subString.swift index 2a7b9e58db2d..24cc04808e6c 100644 --- a/test/stdlib/subString.swift +++ b/test/stdlib/subString.swift @@ -31,6 +31,41 @@ func checkHasContiguousStorageSubstring(_ x: Substring.UTF8View) { expectTrue(hasStorage) } +fileprivate func slices( + _ s: String, + from: Int, + to: Int +) -> ( + Substring, + Substring, + Substring +) { + let s1 = s[s.index(s.startIndex, offsetBy: from) ..< + s.index(s.startIndex, offsetBy: to)] + let s2 = s1[s1.startIndex.. Bool { + s.allSatisfy { $0.isEmpty == false } +} + +fileprivate func allEqual( + _ s: Substring... +) -> Bool { + for i in 0..