Fix the "instanceof" operator to check if the constructor's prototype
property occurs anywhere in the prototype chain of the instance object.
This patch also adds Object.setPrototypeOf() to make it possible to
create a test for this bug.
Thanks to DexesTTP for pointing this out! :^)
This operator walks the prototype chain of the RHS value and looks for
a "prototype" property with the same value as the prototype of the LHS.
This is pretty cool. :^)
NewExpression mostly piggybacks on the existing CallExpression. The big
difference is that "new" creates a new Object and passes it as |this|
to the callee.
Unary expressions parsing now respects precedence and associativity of
operators. This patch also makes `typeof` left-associative which was
an oversight.
Thanks to Conrad for helping me work this out. :^)
We were interpreting "undefined" as a variable lookup failure in some
cases and throwing a ReferenceError exception instead of treating it
as the valid value "undefined".
This patch wraps the result of variable lookup in Optional<>, which
allows us to only throw ReferenceError when lookup actually fails.
You can now throw an expression to the nearest catcher! :^)
To support throwing arbitrary values, I added an Exception class that
sits as a wrapper around whatever is thrown. In the future it will be
a logical place to store a call stack.
You can now throw exceptions by calling Interpreter::throw_exception().
Anyone who calls ASTNode::execute() needs to check afterwards if the
Interpreter now has an exception(), and if so, stop what they're doing
and simply return.
When catching an exception, we'll first execute the CatchClause node
if present. After that, we'll execute the finalizer block if present.
This is unlikely to be completely correct, but it's a start! :^)
We can now handle scripts with if/else in LibJS. Most of the changes
are about fixing IfStatement to store the consequent and alternate node
as Statements.
Interpreter now also runs Statements, rather than running ScopeNodes.
When the Heap is going down, it's our last chance to run destructors,
so add a separate collector mode where we simply skip over the marking
phase and go directly to sweeping. This causes everything to get swept
and all live cells get destroyed.
This way, valgrind reports 0 leaks on exit. :^)
Object now has virtual get_own_property() and put_own_property() member
functions that can be overridden to provide custom behavior.
We use these virtuals to move Array-specific access behavior to Array.
- move() the property map when constructing ObjectExpression instead of
making a copy.
- Use key+value iterators to traverse the property map in the execute()
and dump() functions.
