Normally the storage would be expanded by set_shape() upon transition
to a new shape, but if the shape is already unique, there is no new
transition so we have to expand the storage manually.
It turns out "delete" is actually a unary op :)
This patch implements deletion of object properties, it doesn't yet
work for casually deleting properties from the global object.
When deleting a property from an object, we switch that object to
having a unique shape, no longer sharing shapes with others.
Once an object has a unique shape, it no longer needs to care about
shape transitions.
JS::Value already has the empty state ({} or Value() gives you one.)
Use this instead of wrapping Value in Optional in some places.
I've also added Value::value_or(Value) so you can easily provide a
fallback value when one is not present.
This is required for template literals - we're not quite there yet, but at
least the parser can now tell us when this token is encountered -
currently this yields "Unexpected token Invalid". Not really helpful.
The character is a "backtick", but as we already have
TokenType::{StringLiteral,RegexLiteral} this seemed like a fitting name.
This also enables syntax highlighting for template literals in the js
REPL and LibGUI's JSSyntaxHighlighter.
- Let undefined variables throw a ReferenceError by using
Identifier::execute() rather than doing variable lookup manually and
ASSERT()ing
- Coerce value to number rather than ASSERT()ing
- Make code DRY
- Add tests
This is a special kind of byte array that clamps its values to 0...255
It will be used for HTML ImageData objects.
I made Object::put_by_index() and get_by_index() virtual for this.
We'll probably need to make non-numeric property name lookups virtual
as well, but this solves my current problem well enough.
value and bound arguments
This allows Function objects produced by Function.prototype.bind, as well
as arrow functions to track their |this| values and bound arguments.
This allows us to run "run-tests -g" for testing with GC after every
heap allocation. This may flush out bugs that would otherwise not
occur if GC'ing only occasionally.
A MarkedValueList is basically a Vector<JS::Value> that registers with
the Heap and makes sure that the stored values don't get GC'd.
Before this change, we were unsafely keeping Vector<JS::Value> in some
places, which is out-of-reach for the live reference finding logic
since Vector puts its elements on the heap by default.
We now pass all the JavaScript tests even when running with "js -g",
which does a GC on every heap allocation.
