Boa: Hoisting variables

[hello2dj]

now not founding Identifier will always be undefined, for function or var this is wrong.

moreinfo

example:

// v8
console.log(A); // [Function: A]
function A() {}

// boa
console.log(A); // undefined
function A() {}

[Razican]

This seems to be related to the fact that we execute nodes in order, instead of having a special category for this. These functions should be evaluated first, and then start evaluating the rest of statements.

[jasonwilliams]

I don't think v0.9.0 is realistic for this, for hoisting to work would require a big refactor of how execution works, including having some pre-parsing step.

We're no where near that point yet.

[Razican]

I don't think v0.9.0 is realistic for this, for hoisting to work would require a big refactor of how execution works, including having some pre-parsing step.

We're no where near that point yet.

Actually, this seems to be already working in #392. The Idea was to re-order function declarations to show before all the rest of the nodes in the node list. Not sure what else should be done.

[jasonwilliams]

oh ok interesting.
Should we be doing something more closely related to https://v8.dev/blog/preparser#variable-allocation? is reordering sound?

[Razican]

Should we be doing something more closely related to https://v8.dev/blog/preparser#variable-allocation?

Definitelly, but I think it's a reasonable workaround in the meantime.

is reordering sound?

It should be, it's slower, as we will be doing a sort, but it's always maintaining ordering, so it's sound as far as I can tell.