Re: Features you would like to see

[David Manura <dm.lua@...>]

Patrick Donnelly writes:
> I'm curious what features people would like to see added to Lua.

See http://lua-users.org/wiki/FeatureProposals .

Some of my own favorites include

 http://lua-users.org/wiki/ResourceAcquisitionIsInitialization
   (RAII or scope guards to more effectively solve some cleanup problems)
 http://lua-users.org/wiki/LuaModuleFunctionCritiqued
   (modules should not touch global variables)
 http://lua-users.org/wiki/StatementsInExpressions
   (e.g. the "let" syntax)
 http://lua-users.org/wiki/LuaVirtualization
   (e.g. __len, __pairs, and other metamethods on tables)

Possibly also: macros (in the LISP sense).

> I'd like to see some sort of "default" value for function arguments
> added. Something along the lines of:
> 
> function foo(a or 5)
>   ...
> end;
> ..... a = a or 5; ... end;. Syntactic sugar maybe?

Function argument processing involves a lot of things, including type and range
checking for named and positional elements.  I think the above might add more
complexity to the language but only address one special case.

> I'd like to see some sort of table.hole value for table arrays.

I think the more fundamental issue is in the limited expressibility of varargs
in the absence of tables -- http://lua-users.org/wiki/VarargTheSecondClassCitizen