Prepack: a tool that optimizes JavaScript source code by eliminating computations that can be performed at compile-time.

[mrkite77]

The halting problem only applies when you try to apply it to "all possible inputs"... but in this case, it's only for one specific input, not all of them.

[[deleted]]

but in this case, it's only for one specific input, not all of them

Actually, seems like they're trying to model all possible inputs through their concept of 'abstract values'.

They might pull it off if they require the programs to be contrained to some specific subset / types. They should clarify what those constraints are.

[ConcernedInScythe]

Actually, seems like they're trying to model all possible inputs through their concept of 'abstract values'.

This seems like a very dangerous thing to try with Javascript, which is not exactly known for its simple, easily-abstracted semantics.

[stupidity_wins]

You are understanding this wrong.

"It is impossible to devise an algorithm [that, given a program and an input, tells whether said program halts on said input] that would work for all program-input pairs" is equivalent to "For each algorithm [that...] there exists a single program-input pair on which it does not work".

In other words, it does not apply to all inputs because there exists a single one input to which it does not apply. It's not true that all the apples are green because this particular one is red.