Re: [ANN] A catcode patch

[Dirk Laurie <dpl@...>]

> 
> What kind of uses do you have in mind for dynamic catcodes?
> 
None that could not be achieved by static catcodes, but different 
people need different things and one does not wish to recompile
every time.

So, in no particular order, and just for a start:

1. The underscore is overworked.  

2. Some interesting one-character function names.

-- get/set metatables
setcatcode('@','A')
function @(obj,mt) 
  if mt==nil then return getmetatable(obj) else setmetatable(obj,mt) end
  end

-- function mimicking C-style ternary operator
setcatcode('?','A')
function ?(a,b,c) 
    if a then return b else return c end
    end

-- address of tables, objects, files
setcatcode('&','A')
function &(obj) 
    obj = string.match(tostring(obj),"(0x.......)")
    if obj then return obj end
    error("No 8-digit hexadecimal address found")
    end

-- lightweight functions
setcatcode("!","A")
function !(x,fx) return load(x.."=... return "..fx) end

3. Pander to nostalgia among Perl and Ruby apostates.

Dirk