Previously, the Object class had many different types of functions for
each action. For example: get_by_index, get(PropertyName),
get(FlyString). This is a bit verbose, so these methods have been
shortened to simply use the PropertyName structure. The methods then
internally call _by_index if necessary. Note that the _by_index
have been made private to enforce this change.
Secondly, a clear distinction has been made between "putting" and
"defining" an object property. "Putting" should mean modifying a
(potentially) already existing property. This is akin to doing "a.b =
'foo'".
This implies two things about put operations:
- They will search the prototype chain for setters and call them, if
necessary.
- If no property exists with a particular key, the put operation
should create a new property with the default attributes
(configurable, writable, and enumerable).
In contrast, "defining" a property should completely overwrite any
existing value without calling setters (if that property is
configurable, of course).
Thus, all of the many JS objects have had any "put" calls changed to
"define_property" calls. Additionally, "put_native_function" and
"put_native_property" have had their "put" replaced with "define".
Finally, "put_own_property" has been made private, as all necessary
functionality should be exposed with the put and define_property
methods.
Passing a Heap& to it only to then call interpreter() on that is weird.
Let's just give it the Interpreter& directly, like some of the other
to_something() functions.
There are now two API's on Value:
- Value::to_string(Interpreter&) -- may throw.
- Value::to_string_without_side_effects() -- will never throw.
These are some pretty big sweeping changes, so it's possible that I did
some part the wrong way. We'll work it out as we go. :^)
Fixes#2123.
Everyone who constructs an Object must now pass a prototype object when
applicable. There's still a fair amount of code that passes something
fetched from the Interpreter, but this brings us closer to being able
to detach prototypes from Interpreter eventually.
Let's move towards using references over pointers in LibJS as well.
I had originally steered away from it because that's how I've seen
things done in other engines. But this is not the other engines. :^)
Instead of implementing every native function as a lambda function,
use static member functions instead.
This makes it easier to navigate the code + backtraces look nicer. :^)
Native functions now only get the Interpreter& as an argument. They can
then extract |this| along with any indexed arguments it wants from it.
This forces functions that want |this| to actually deal with calling
interpreter.this_value().to_object(), and dealing with the possibility
of a non-object |this|.
This is still not great but let's keep massaging it forward.
This patch adds the EventTarget class and makes Node inherit from it.
You can register event listeners on an EventTarget, and when you call
dispatch_event() on it, the event listeners will get invoked.
An event listener is basically a wrapper around a JS::Function*.
This is pretty far from how DOM events should eventually work, but it's
a place to start and we'll build more on top of this. :^)