* 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
* Refactor Indices and Slice to use conditional conformance
* Replace ReversedRandomAccessCollection with a conditional extension
* Refactor some types into struct+extensions
* Revise Slice documentation
* Fix test cases for adoption of conditional conformances.
* [RangeReplaceableCollection] Eliminate unnecessary slicing subscript operator.
* Add -enable-experimental-conditional-conformances to test.
* Gruesome workaround for crasher in MutableSlice tests
CharacterView is now entirely redundant in Swift 4. Deprecate its
use. This also allows us to schedule the unbreaking of
String.CharacterView leakiness without a hard source break.
Collection's popFirst is only present when the Collection is its own
SubSequence type. String and String's views are no longer their own
SubSequenes, so popFirst is no longer present. Unfortunately, this
breaks code in swift-version 3 and it also gives a terrible diagnostic
to users. This change introduces an implementation for swift-version 3
mode and better diagnostics for Swift 4 code. Tests included.
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.
Substring's _persistentContent has a fast path that avoids a copy when
the Substring represents the entire outer String. It correctly
detected situations where the wrapped _StringCore was not itself a
slice, but was omitting the extra checks to make sure the Substring's
own range covered the entire String.
Test added.
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.
* Use _ephemeralString for substring comparison
Add back != for String/Substring comparison
* OK fine, Linux, if you're going to be difficult
* Different forms of comparison, tests
- remove additional 'characters' references from String docs
- improved language around escaping pointer arguments
- key path type abstracts
- codable type abstract revisions
- a few more NSString API fixes
* One-sided ranges and RangeExpression
* Remove redundant ClosedRange methods from String
* Fix up brittle tests
* Account for Substring update
* XFAIL range diagnostics on Linux
