Re: [PATCH] Jump Tables for Switch/Case and Computed Goto

[Karel Tuma <kat@...>]

Excerpts from Paige DePol's message of 2014-05-06 07:21:47 +0200:
> What? I have no idea what you mean by that? It is not something I said.
> Essentially I did make addressable identifiers, that can be any constant value.

In 1.5k LOC patch. All I am saying it might be worth it to think about
in terms of doing more in less.

> You can jump when there is a sub-scope. You can jump over it, just not into it.
> Why would we need to do that, we know at compile time if all jumpto statements can reach all jump points without violating local scope.

I suppose code will explain better:

-- no jumping to outside scope
do
  local x = 1
  do
    jumpto x -- should jump to 1 ...
    :|2|: -- to satisfy static scoping check
  end
  :|1|:
  os.exit()
  jumpto x -- to satisfy static scoping check
end
-- lua equivalent:
-- jumping to outside scope
do
  do
    goto out
  end
  ::out::
end


-- no jumping into scope of local variable
do
  local x = 1
  jumpto x
  :|1|:

  local b = 2
  :|2|:
  jumpto b
end

-- no lua equivalent because lua uses static check
-- too (but for static gotos)

Doing dynamic gotos with static scoping is rather um ... unorthodox.
Common usage is to err ... jump to outside scope I guess?

> Thank you for your feedback, though I have to be honest, I did not understand half of it! :(

No worries, thats what they call code talks, bullshit walks.