Re: Aspect Oriented Programming

[Javier Guerra Giraldez <javier@...>]

2011/1/3 Gustavo de Sá Carvalho Honorato <gustavohonorato@gmail.com>:
> Hi,
>
> is there any easy way to work with Aspects in Lua? I've found this
> project (http://aspectlua.luaforge.net/) but it seems to be quite old.

as many things OO, most 'fun' things in aspects are trivial to do in
functional programming:

for example, it's common to enhance the built-on type() function:

do
  local oldtype = type
  function type(x)
    local mt = getmetatable(x)
    if mt and mt.__type then return mt.__type end
    return oldtype(x)
  end
end

or you could do some 'prepend' functions:

function prepend(f,pre)
  return function(...)
    return pre(f,...)
  end
end


and use like this:

type = prepend (type, function(old, x)
  local mt = getmetatable(x)
  if mt and mt.__type then return mt.__type end
  return old(x)
end




-- 
Javier