upcoming changes in Lua 5.2 [was Re: Location of a package]

[Roberto Ierusalimschy <roberto@...>]

> Roberto, is there any description of upcoming changes in Lua 5.2?

There is no "official" roadmap :) The following is a list of what we
have been doing.

We have already implemented several small changes:

- emergency garbage collector (core forces a GC when allocation fails)

- ephemeron tables (tables with weak keys only visit value when
key is accessible)

- handling of non-string error messages (somewhat along the lines of
John Belmonte's suggestion)

- new function package.searchpath

- "metamethods" __pairs & __ipairs

- tables and strings respect __len metamethod

- udata with finalizers are kept in a separated list for the GC

- arguments for function called through xpcall


We are also considering the following changes:

- string.pack/string.unpack (along the lines of struct/lpack)

- Mike Pall's implementation for yield (using longjmp), allowing yields
in several places not allowed currently (inside pcall, metamethods, etc.)

- some form of bit operations. (We are not very happy with any
known implementation. Maybe just incorporate bitlib?)

- there is already a new function luaL_tolstring (along the lines of
the 'tostring' function). Maybe we should define a lua_rawtostring (no
coercions from numbers) and then use luaL_tolstring ("full" coercion
from other types) when we want to allow coercions. The point is where
to use one and where to use the other. (The current lua_tostring behavior
would be deprecated in the future...)


-- Roberto