dsimcha wrote:
== Quote from Andrei Alexandrescu (seewebsiteforem...@erdani.org)'s article
dsimcha wrote:
2. I don't understand how this solves the safety problem:
// foo lives on the heap b/c we've idup'd it.
string foo = "This is only a test.".idup;
string bar = foo[0..4];
bar ~= " is _not ";
writeln(foo); // prints "This is _not a test."
Having access to the capacity in an LRU cache doesn't help if I understand it
correctly.
Let me stress a point harder that I think I expressed poorly:
The LRU cache stores the capacity of a given slice given _BOTH_ the
slice's left and right bounds. If you later come with a slice that has
only one correct bound, the LRU doesn't care about it. That's the safety
tidbit.
Andrei
I think I get it now, although it's very conservative.
That's why we need experimentation. My gut tells me that linear search
will scram through 8 elements real fast, and if there's something in the
cache it will almost always be in a top position. Also, I think the LRU
will solve all cases that matter.
One more question: Is
this going to take the place of ArrayBuilder or be inaddition? The LRU is a
good
hack to preserve syntactic elegance and ease of use, but it's somewhat of a
kludge
nonetheless and I'd ideally still like to see a real ArrayBuilder with full
array-like semantics if T[new] is definitely out.
Ideally we'd be able to render ArrayBuilder/Appender unnecessary. I
think there is a need for a UniqueArray, but that's only loosely related.
Andrei
