Re: [PATCH] experimental php-like 'break N' to break across multiple loops

[Rici Lake <lua@...>]

On 31-Oct-06, at 4:55 PM, Karel Tuma wrote:

> hi listers,
>
> i've found myself doing lot of miserable things today, due to 
> inability of lua
> to simply break out of multiple nested breakable scopes in one 
> statement.

One reasonably simple way of doing it is to put the multiple nested 
loops into a function, and returning. You can even use an inline 
anonymous function:

local eekval = (function()
  while foo() do
    while bar() do
      if baz() then return eek() end
    end
  end
end)()

But I understand that isn't everyone's cup of tea.

> finding nothing useful in powerpatches archive i wrote this rather 
> naive
> and unintrusive patch - so there is generally no reason why it 
> shouldn't work,
> but i've tested it extensively only with various for/while nested 
> loops.

This topic (or something vaguely related) came up on IRC today so I 
happen to have this link to the mailing list from a year ago handy:

http://lua-users.org/lists/lua-l/2005-10/msg00037.html

If you follow that thread to the end, you'll find a patch I wrote 
against Lua 5.1-alpha (link and syntax in this message: 
http://lua-users.org/lists/lua-l/2005-10/msg00057.html )

I haven't updated that patch to 5.1.1 because there didn't seem to be 
any demand for it. Of course, it's a lot more intrusive to the 
language. It shouldn't be too difficult to upgrade.