It turns out return a ThrowCompletionOr<T const&> is flawed, as the GCC
expansion trick used with TRY will always make a copy. PrimitiveString
is luckily the only such use case.
This makes construction of Utf16String fallible in OOM conditions. The
immediate impact is that PrimitiveString must then be fallible as well,
as it may either transcode UTF-8 to UTF-16, or create a UTF-16 string
from ropes.
There are a couple of places where it is very non-trivial to propagate
the error further. A FIXME has been added to those locations.
This constructor was easily confused with a copy constructor, and it was
possible to accidentally copy-construct Objects in at least one way that
we dicovered (via generic ThrowCompletionOr construction).
This patch adds a mandatory ConstructWithPrototypeTag parameter to the
constructor to disambiguate it.
Note that js_rope_string() has been folded into this, the old name was
misleading - it would not always create a rope string, only if both
sides are not empty strings. Use a three-argument create() overload
instead.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Intrinsics, i.e. mostly constructor and prototype objects, but also
things like empty and new object shape now live on a new heap-allocated
JS::Intrinsics object, thus completing the long journey of taking all
the magic away from the global object.
This represents the Realm's [[Intrinsics]] slot in the spec and matches
its existing [[GlobalObject]] / [[GlobalEnv]] slots in terms of
architecture.
In the majority of cases it should now be possibly to fully allocate a
regular object without the global object existing, and in fact that's
what we do now - the realm is allocated before the global object, and
the intrinsics between both :^)
- Prefer VM::current_realm() over GlobalObject::associated_realm()
- Prefer VM::heap() over GlobalObject::heap()
- Prefer Cell::vm() over Cell::global_object()
- Prefer Wrapper::vm() over Wrapper::global_object()
- Inline Realm::global_object() calls used to access intrinsics as they
will later perform a direct lookup without going through the global
object
Instead of passing a GlobalObject everywhere, we will simply pass a VM,
from which we can get everything we need: common names, the current
realm, symbols, arguments, the heap, and a few other things.
In some places we already don't actually need a global object and just
do it for consistency - no more `auto& vm = global_object.vm();`!
This will eventually automatically fix the "wrong realm" issue we have
in some places where we (incorrectly) use the global object from the
allocating object, e.g. in call() / construct() implementations. When
only ever a VM is passed around, this issue can't happen :^)
I've decided to split this change into a series of patches that should
keep each commit down do a somewhat manageable size.
This is a continuation of the previous five commits.
A first big step into the direction of no longer having to pass a realm
(or currently, a global object) trough layers upon layers of AOs!
Unlike the create() APIs we can safely assume that this is only ever
called when a running execution context and therefore current realm
exists. If not, you can always manually allocate the Error and put it in
a Completion :^)
In the spec, throw exceptions implicitly use the current realm's
intrinsics as well: https://tc39.es/ecma262/#sec-throw-an-exception
This is a continuation of the previous two commits.
As allocating a JS cell already primarily involves a realm instead of a
global object, and we'll need to pass one to the allocate() function
itself eventually (it's bridged via the global object right now), the
create() functions need to receive a realm as well.
The plan is for this to be the highest-level function that actually
receives a realm and passes it around, AOs on an even higher level will
use the "current realm" concept via VM::current_realm() as that's what
the spec assumes; passing around realms (or global objects, for that
matter) on higher AO levels is pointless and unlike for allocating
individual objects, which may happen outside of regular JS execution, we
don't need control over the specific realm that is being used there.
After the Intl MV is implemented, returning a copy of the desired value
here may involve copying non-trivial data. Instead, return an enum to
indicate which decision was made.
This becomes more of an issue when implementing the Intl mathematical
value, where negative zero is treated as a special enum value. In that
case, we already previously changed the value from -0 to +0 in step 1b.
Entering the branch for step 4 will then set it back to -0.
The math that follows after these steps worked fine with both +0/-0, but
assertions will be reached in the Intl MV implementation.
These were changed to i8 while investigating the issues fixed by commit
9e50f25. When [[RoundingIncrement]] is implemented, some of these will
be invoked with [[RoundingIncrement]]'s value, which can be up to 5000.
Change these to i32, and wrap them with AK::Checked for good measure.
Also change a couple helpers that are always comparing against zero to
not need an explicit check.
The largest exponents we compute are on the order of 10^21 (governed by
the maximumSignificantDigits option, which has a max value of 21). That
is too large to fit into the i64 we were using when multiplying this
exponent by the value to be formatted.
Instead, split up the logic to multiply that value by this exponent
based on the value's underlying type:
Number: Do not cast the result of pow() to an i64, and perform the
follow-up multiplication with doubles.
BigInt: Do not use pow(). Instead, compute the exponent as a BigInt
from the start, then perform the follow-up multiplication with that
BigInt.
In the main spec, [[UseGrouping]] can be true or false. In V3, it may be
one of:
auto: Respect the per-locale preference for grouping.
always: Ignore per-locale preference for grouping and always insert
the grouping separator (note: true is now an alias for always).
min2: Ignore per-locale preference for grouping and only insert the
grouping separator if the primary group has at least 2 digits.
false: Ignore per-locale preference for grouping and never insert
the grouping separator.
This contains minimal changes to parse newly added and modified options
from the Intl.NumberFormat V3 proposal, while maintaining main spec
behavior in Intl.NumberFormat.prototype.format. The parsed options are
reflected only in Intl.NumberFormat.prototype.resolvedOptions and the js
REPL.
This also allows removing a bit of a BigInt hack to resolve plurality of
BigInt numbers (because the AOs used in ResolvePlural support BigInt,
wherease the naive Unicode::select_pattern_with_plurality did not).
We use cardinal form here; the number format patterns in the CLDR align
with the cardinal form of the plural rules.
Intl.NumberFormat is meant to format both Number and BigInt types. To
prepare for formatting BigInt types, this generalizes our NumberFormat
implementation to operate on Value instances rather than doubles. All
arithmetic is moved to static helpers that can now be updated with
BigInt semantics.
Other Intl objects, such as PluralRules, are to be treated as a
NumberFormat object in some AOs. There's only a handful of fields which
are to be shared between those objects - move them to a base class for
shared reuse.
This also updates the couple of NumberFormat AOs that are meant to
operate on these NumberFormat-like objects.
Alternatively, we could just have objects like PluralRules inherit from
NumberFormat directly. But that messes up the is<NumberFormat> runtime
checks, so this feels safer.
