hashBits() is used to generate a hash code from the same 64 bits used
to represent a Wren number as a double. When building a map containing
a large number of integer keys, it's important for this to do a good
job scattering the bits across the 32-bit key space.
Alas, it does not. Worse, the benchmark to test this happens to stop
just before the performance falls off a cliff, so this was easy to
overlook.
This replaces it with the hash function V8 uses, which has much better
performance across the numeric range.
The intent of the assert is to ensure that insertEntry() is not called
with an empty entries array because that would cause you to get into a
code path where the entry output parameter is not set. But the assert
didn't correctly check that.
Fix#635.
This doesn't let you arbitrarily call back into the VM from within
foreign methods. I'm still not sure if that's even a good idea since
God knows what that would mean if you switch fibers while doing that.
But this does allow the very important use case of being able to call
a foreign method from within a call to wrenCall(). In other words,
foreign methods need to always be leaf calls on the call stack, but the
root of that stack can now come from runInterpreter() or wrenCall().
Fix#510.
When parsing the string token if a `\` was used it would
unconditionally consume the next character. This would led to a token
with an invalid lenght causing a crash when it was printed. This fixes
that by only consuming the token after the `\` if there is one to
consume.
Fixes#603
The VM used to not detect this case. It meant you could get into a
situation where another fiber's caller had completed. Then, when it
tried to resume that fiber, the VM would crash because there was nothing
to resume to.
This is part of thinking through all the cases around re-entrancy. Added
some notes for that too.
There's a lot of changes here and surely some rough edges to iron out.
Also, I need to update the docs. But I want to get closer to landing
this so I can build on it.
- Fix some doc comments.
- Inline comparing two ObjStrings, since it's only used in one place.
Also, this avoids a redundant identity check.
- Move the forward declarations of the object types out of
wren_common.h. Instead, I just added the one needed forward
declaration of ObjString in wren_utils.h. It's a little inelegant,
but it feels weird to me to expose all of the object types in
wren_common.h when they logically belong to wren_value.h and most of
the types aren't problematic.
- Fix a bug where field symbol tables weren't being marked. If a GC
happened while compiling a class, field strings got freed.
