ICU's uText APIs offer a cross-encoding means of interacting with
grapheme breaking. Storing one on our TLS allows us to explore mised
encodings, and even for UTF-16 might be profitable if setText
mallocs/frees an internal uText (which seems to be the case). This
isn't hooked up to anything yet, but its highly likely we will be
using it soon and adding it now enables more rapid development of the
UTF-8 prototype, due to it's tie-in with the runtime.
`\.self` is the final chosen syntax. Implement support for this syntax, and remove the stopgap builtin and `WritableKeyPath._identity` property that were in place before.
* add count(where:) and tests
* Revise count(where:) documentation
* Remove errant word in abstract
* add a benchmark for ranges and strings with help from @natecook1000
* update benchmark to use Array instead of Range
Now that we have removed overriding protocol requirements from witness
tables, they no longer have any effect on the ABI. Replace the FIXME
(ABI) comments with normal FIXMEs: there is no more ABI work to do
here.
Add the `-warn-implicit-overrides` flag when building the standard library
and overlays, so that each protocol member that overrides a member of an
inherited protocol will produce a warning unless annotated with either
‘override’ or ‘@_nonoverride’.
An annotation of `override` will mean that the overriding requirement will be treated identically to the overridden declaration. If for some reason a concrete type’s conformance to the inheriting protocol provides a different witness for the overriding requirement than the conformance to the inherited protocol’s witness for the overridden requirement, the witness for the inheriting (more-specialized) protocol will be ignored. A protocol requirement marked ‘override’ only makes sense when the declaration is needed to help associated type inference, which is why the ‘override’ annotations correlate so closely with ABI FIXMEs.
An annotation of `@_nonoverride` means that the two protocol requirements will be treated independently, and may be bound to different witnesses. Use `@_nonoverride` when we might need different witnesses, e.g., because the semantics of the potentially-overriding declaration differ from that of the potentially-overridden declaration. `BidirectionalCollection.index(_:offsetBy:)` is the most obvious example, because the `BidirectionalCollection` ’s version of `index(_:offsetBy:)` allows negative indices. `RandomAccessCollection` ’s version is also marked `@_nonoverride` because it is required to be asymptotically faster than the `Collection` or `BidirectionalCollection` versions.
In order to provide source compatibility with existing user types conforming to BinaryInteger, we want to have a default implementation available. It's somewhat difficult to provide a good default implementation that correctly handles arbitrary non-symmetrical ranges in the face of negative divisors, so fall back on testing divisibility of the magnitudes, which avoids the problem.
On the plus side, this default implementation works fine for types conforming to UnsignedInteger, which lets us move the FixedWidthInteger implementation down to FixedWidthInteger & SignedInteger, and simplify it in the process.
* Implement SE-0225 (BinaryInteger.isMultiple(of:))
A default implementation is provided for FixedWidthInteger, with very basic test coverage included.
This should have been done for Swift 4.2 according to SE-0204, but
better later than never. Deprecating these methods as of Swift 5.0.
Also modfying the tests to check for the deprecation message.
Fixes: <rdar://problem/43694210>
* Obsolete ModifierSlice typealiases in 5.0
* Obsolete *Indexable in 5.0
* Obsolete IteratorOverOne/EmptyIterator in 5.0
* Obsolete lazy typealiases in 5.0
* Drop .characters from tests
* Obsolete old literal protocols in 5.0
* Obsolete Range conversion helpers in 5.0
* Obsolete IndexDistance helpers in 5.0
* Obsolete Unsafe compat helpers in 5.0
* Obsolete flatMap compatibility helper in 5.0
* Obsolete withMutableCharacters in 5.0
* Obsolete customPlaygroundQuickLook in 5.0
* Deprecate Zip2Sequence streams in 5.0
* Replace * with swift on lotsa stuff
* Back off obsoleting playground conformances for now
When working with Error types with unsigned raw values, numeric-cast into
a UInt and then map the bits over to an Int so we preserve values not
representable in an Int without wrapping.
Thanks to @jrose-apple for pointing this out!
Simplify the default implementations provided for RawRepresentable
error types whose raw values are integral, replacing duplicated code
(for SignedInteger or UnsignedInteger) with a single constraint on
BinaryInteger.
Fixes rdar://problem/35230187.
This enables in-place mutations of the key-based subscript.
These get rid of one of two full hash table lookup operations (including hashing the key) relative to the getter+setter approach. They can also eliminate COW copies in code like this:
dictionary[foo]?.append(bar)
(Admittedly this isn’t a very useful example.)
