...because it is apparently more efficient in some cases. Technically
we don't do this in ALL places, because it would be unfortunate if
the implementation of _successorInPlace() were self recursive :-)
At DaveA's suggestion, I took a mostly mechanical approach to this:
pointers and numeric types start using += 1, and indexes use
i = i.successor(). The index model is likely to be revised in
Swift 3 anyway, so micro-optimizing this code syntactically isn't
super important.
There is some performance concern of this patch, since some
in-place succesor operations are more efficient than
i = i.successor(). The one that seems particularly at issue is the
instance in the implementation of partition(), which I changed to
use i._successorInPlace(). If other instances lead to a perf issue,
they can be changed to use that as well.
This reflects the fact that the attribute's only for compiler-internal use, and isn't really equivalent to C's asm attribute, since it doesn't change the calling convention to be C-compatible.
rdar://problem/21663830
Add the following new requirements to SequenceType with default implementations:
- dropFirst(n)
- dropLast(n)
- prefix(n)
- suffix(n)
- split(n)
In addition, provide specialized default implementations of these for CollectionTypes with forward, bidirectional, and random-access Index types where possible.
Add the following new requirements to CollectionType with default implementations:
- prefixThrough(n)
- prefixUpTo(n)
- suffixFrom(n)
- split() // isSeparator closure
Add the following convenience APIs:
- dropFirst() -> calls dropFirst(1)
- dropLast() -> calls dropLast(1)
Add a tentative underscored API:
- split() // takes Equatable separator.
Some APIs have undefined behavior when creating slices where the endpoints go beyond the bounds of the underlying collection. This will be fixed later by trapping creation of slices with invalid indices (rdar://problem/21822657).
Swift SVN r30371
The protocol is still needed in order to make sure mixed signed/unsigned
arithmetic doesn't compile, but after pulling all its "real"
requirements into UnsignedIntegerType, that's now its only function.
Thus, rename it to _DisallowMixedSignArithmetic.
Swift SVN r28980
This came out of today's language review meeting.
The intent is to match #available with the attribute
that describes availability.
This is a divergence from Objective-C.
Swift SVN r28484
The rule changes are as follows:
* All functions (introduced with the 'func' keyword) have argument
labels for arguments beyond the first, by default. Methods are no
longer special in this regard.
* The presence of a default argument no longer implies an argument
label.
The actual changes to the parser and printer are fairly simple; the
rest of the noise is updating the standard library, overlays, tests,
etc.
With the standard library, this change is intended to be API neutral:
I've added/removed #'s and _'s as appropriate to keep the user
interface the same. If we want to separately consider using argument
labels for more free functions now that the defaults in the language
have shifted, we can tackle that separately.
Fixes rdar://problem/17218256.
Swift SVN r27704
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876
