Trying to lazily compute bridge results and cache them isn't going to
work, because there's no place to efficiently invalidate the cache in
cases like this:
func f(a: NSArray) {
for i in 0...a.count {
println(a.objectAtIndex(i)) // Fills up the cache
}
}
var message = ["hello", "world"]
f(message)
message[0] = "goodbye, cruel" // need a cache invalidation or else
f(message) // ...this prints "hello\nworld\n"
Since we need C performance for subscript assignment, we just can't
afford to do anything extra there.
Instead, when the element type isn't "Bridged Verbatim," just eagerly
convert it to an NSArray.
Swift SVN r17722
We were wishfully thinking that we could convert all NSArrays lazily.
However, since non-class/existential types are supposed to have a
statically-knowable efficient representation we need an eager conversion
in those cases.
Swift SVN r17538
Chris suggested that we should lazily typecheck each element when an
NSArray is downcast to Array<T>. That sounded like a good idea, and
along the way we decided to simplify the implementation and spec by not
bending over backwards to allow broken duck-typing to work for pure ObjC
classes.
Swift SVN r17468
Chris suggested that we should lazily typecheck each element when an
NSArray is downcast to Array<T>. That sounded like a good idea, and
along the way we decided to simplify the implementation and spec by not
bending over backwards to allow broken duck-typing to work for pure ObjC
classes.
Swift SVN r17408
There's little point in allowing Array<T> to have both direct and
indirect representations when T can be a class type. Let's drop the
branch cost and generate less code.
Swift SVN r17353
There's no need to support up- or down-casts for NativeArray<T> or
Slice<T>. Slice might turn out to be easy, but we don't have time right
now. Doing it for NativeArray<T> would have efficiency costs that we
don't want to pay.
Swift SVN r17323
This is a partial update. We need to decide how to rework array
up-/down-casting to account for value semantics changes. Will post to
the list.
Swift SVN r17254
For now we're going to keep BridgedToObjectiveC as a private internal
implementation detail. Adding the "_" prefix marks it as internal.
Implements <rdar://problem/16736672>.
Swift SVN r16921
