In grand LLVM tradition, the first step to redesigning _StringCore is
to first rename it to _LegacyStringCore. Subsequent commits will
introduce the replacement, and eventually all uses of the old one will
be moved to the new one.
NFC.
* Nest various top-level Iterator and Index types, and flatten extensions.
* Fix tests from nesting iterator
* Nest Unsafe*BufferPointer.Iterator, extensionify UnsafeBufferPointer
* Degyb LazyCollection
* Nest Flatten iterator and index
* 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
This necessary for ensuring the property that String doesn't keep
inaccessible memory alive. For example, before this change,
String(s.dropFirst().unicodeScalars)
would compile and produce a String that owned inaccessible memory.
Now it no longer compiles.
String's view's SubSequences are the same as the Substring's
view. E.g. String.UnicodeScalarView.SubSequence is
Substring.UnicodeScalarView.
New compatibility inits added, to work around the fact that many
previously failable initializers are now non-failable.
The simplest way to keep the string buffer alive is simply to always grab its
iterator, even if we're not going to use it. Thanks @milseman for that idea and
@jckarter for the diagnosis help!
I failed to merge the upstream changes to swift-corelibs-foundation at the same
time as I merged that #9806, and it broke on linux. Going to get it right this
time.
* Give Sequence a top-level Element, constrain Iterator to match
* Remove many instances of Iterator.
* Fixed various hard-coded tests
* XFAIL a few tests that need further investigation
* Change assoc type for arrayLiteralConvertible
* Mop up remaining "better expressed as a where clause" warnings
* Fix UnicodeDecoders prototype test
* Fix UIntBuffer
* Fix hard-coded Element identifier in CSDiag
* Fix up more tests
* Account for flatMap changes
* [stdlib] Fix String.UTF16View index sharing
* [stdlib] Fix String.UnicodeScalarView index sharing
* [stdlib] Fix String.CharacterView index sharing
* [stdlib] Test advancing string indices past their ends
* [stdlib] Simplify CharacterView ranged subscript
We should not make grapheme segmentation algorithm inlineable now (and
possibly ever). The immediate reason is that Unicode 8.0 grapheme
segmentation algorithm has been changed significantly in Unicode 9.0.
Unicode 9.0 requires a stateful algorithm. Current indices and
iterators just don't have the storage for that state, so we can't mark
them as fragile.
This is another necessary step in introducing changes
for SE-0107: UnsafeRawPointer.
UnsafeRawPointer is great for bytewise pointer operations.
OpaquePointer goes away.
The _RawByte type goes away.
StringBuffer always binds memory to the correct CodeUnit
when allocating memory.
Before accessing the string, a dynamic element width check
allows us to assume the bound memory type.
Generic entry points like atomicCompareExchange no longer handle
both kinds of pointers. Normally that's good because you
should not be using generics in that case, just upcast
to raw pointer. However, with pointers-to-pointers
you can't do that.
We were using a precondition which crashes the program when invalid input is
provided. We want to provide a way to gracefully check and handle invalid input
or shutdown the program if necessary.
SR-1930
In various cases where we had global operators for non-generic
concrete types (such as String + String), move those operators into
the type. This should not affect the sources, but makes the exposition
of the library cleaner.
Plus, it's a good test for the compiler, which uncovered a few issues
where the compiler was coupled with the library.
This removes the `_core` property from UnicodeScalarView.Index
and moves any remaining index-moving logic from the index to
the view in UnicodeScalarView and CharacterView.
This documentation revision covers a large number of types & protocols:
String, its views and their indices, the Unicode codec types and protocol,
as well as Character, UnicodeScalar, and StaticString, among others.
This also includes a few small changes across the standard library for
consistency.
