This is safe to do with hash(into:), because random hash collisions can be eliminated with awesome certainty by trying a number of different hash seeds. (Unless there is a weakness in SipHash.)
In some cases, we intentionally want hashing to produce looser equivalency classes than equality — to let those cases keep working, add an optional hashEqualityOracle parameter.
Review usages of checkHashable and add hash oracles as needed.
StdlibUnittest uses gyb to avoid duplicating many source-context
arguments. However, this means that any test that wishes to add new
expect helpers has to also be gybbed. Given that this structure hasn't
changed in years, and we should have a real language support
eventually, de-gyb it.
Streamline internal String creation. Previously, everything funneled
into a single generic function, however, every single call of the
generic funnel had relevant specific information that could be used
for a more efficient algorithm.
In preparation for efficiently forming small strings, refactor this
logic into a handful of more specialized subroutines to preserve more
specific information from the callers.
Switch to a resilient hashing interface, currently implementing SipHash-1-3.
Compiler-synthesized Hashable conformances still use the old _combineHashValues interface for now.
Beyond switching hashing algorithms, this also enables per-execution hash seeds, fulfilling a long-standing prophecy in Hashable’s documentation.
To reduce the possibility of random test failures, StdlibUnittest’s TestSuite overrides the random hash seed on initialization.
rdar://problem/24109692
rdar://problem/35052153
* Make Range conditionally a Collection
* Convert ClosedRange to conditionally a collection
* De-gyb Range/ClosedRange, refactoring some methods.
* Remove use of Countable{Closed}Range from stdlib
* Remove Countable use from Foundation
* Fix test errors and warnings resulting from Range/CountableRange collapse
* fix prespecialize test for new mangling
* Update CoreAudio use of CountableRange
* Update SwiftSyntax use of CountableRange
* Restore ClosedRange.Index: Hashable conformance
* Move fixed typechecker slowness test for array-of-ranges from slow to fast, yay
* Apply Doug's patch to loosen test to just check for error
* Eradicate IndexDistance associated type, replacing with Int everywhere
* Consistently use Int for ExistentialCollection’s IndexDistance type.
* Fix test for IndexDistance removal
* Remove a handful of no-longer-needed explicit types
* Add compatibility shims for non-Int index distances
* Test compatibility shim
* Move IndexDistance typealias into the Collection protocol
Make the Indices types conform to the appropriate Collection protocol:
* Collection.Indices: Collection
* BidirectionalCollection.Indices: BidirectionalCollection
* RandomAccessCollection.Indices: RandomAccessCollection
Introduce (recursive) constraints that make the *Collection constraint
of SubSequence match that of its enclosing *Collection, e.g.,
MutableCollection.SubSequence conforms to MutableCollection.
Fixes rdar://problem/20715031 and more of SR-3453.
Addressed ABI FIXME’s #4, #5, #104 and #105, making Sequence’s
SubSequence conform to Sequence, with the same element type, and for
which the SubSequence of a SubSequence is the same SubSequence.
Fixes SR-318 / rdar://problem/31418206.
Addressed ABI FIXME’s #4, #5, #104 and #105, making Sequence’s
SubSequence conform to Sequence, with the same element type, and for
which the SubSequence of a SubSequence is the same SubSequence.
Fixes SR-318 / rdar://problem/31418206.
* Create Swift libSyntax API
This patch is an initial implementation of the Swift libSyntax API. It
aims to provide all features of the C++ API but exposed to Swift.
It currently resides in SwiftExperimental and will likely exist in a
molten state for a while.
* Only build SwiftSyntax on macOS
Cygwin is considered a distinct target with a distinct ABI, environment
conditions, and data types. Though the goal of the project is
native Windows integration with UNIX-likes, that is not compatible with
the idea that the platform can be ignored as Win-like enough to have the
existing os(Windows) condition apply.
Specifically, objc_setUncaughtExceptionHandler, whose nullability is
now annotated in Swift 4 mode when using the Xcode 9 SDKs. That means
it has a different signature in Swift 3 and Swift 4 mode, which means
that references from SIL will fail when deserialized in the other
mode. (The recovery support added in earlier commits doesn't cover
serialized SIL.)
This resulted in crashes when building with
-build-serialized-stdlib-unittest, which enables -sil-serialize-all /
"magic performance mode" when building the StdlibUnittest module like
it does the standard libarry.
None of this affects developer code, because developer code doesn't
serialize anything (if they're playing by the rules).
Part of ABI FIXME #99, this gives us some nice consistency that
ensures that slicing a SubSequence gives us another SubSequence. There
are two source-compatibility implications to this change:
* Collections now need to satisfy this property, which could not be
expressed in Swift 3. There might be some Collections that don't
satisfy this property, and will break with the Swift 4 compiler
*even in Swift 3 compatibility mode*. Case in point...
* The Lazy collection types were formulated as a lazy collection of
the base slice (e.g., LazyCollection<ArraySlice<T>>) rather than as
a slice of the lazy collection (e.g.,
Slice<LazyCollection<Array<T>>). The former doesn't meet the new
requirements, so change to the latter.
Address ABI FIXME #68 by using same-type constraints directly on an
associated type to describe the requirements on the Indices associated
type of the Collection protocol. ABI FIXMEs #89, #90, #91 are all in
StdlibUnittest, and provoke warnings once #68 is fixed, but it's nice
to clear them out.
Fixes SR-2121.
