do .. end patch

[Asko Kauppi <asko.kauppi@...>]

Changing Lua 5.x syntax:
	
	function → function funcbody
to:
	function → function funcbody | do block end


I proposed this a couple of days ago, to get easier 'switch' syntax 
(declaring little funcs as data members).  Now, I took my first lesson 
on touching Lua source internally, and it wasn't hard!  The following 
change (lparser.c, line 776 in 5.1w1) does this, and has no side 
effects whatsoever.

It could be better implemented by changing the 'body' function 
(additional "no paranthesis" flag) but I wanted to have it all in one 
place.

Here goes:

    case TK_FUNCTION: {
      next(ls);
      body(ls, v, 0, ls->linenumber);
      return;
    }
>>>
    case TK_DO: {   //AK: "do ... end" = "function() ... end" (as a 
value)
      next(ls);
      /* body_noparam ->  chunk END */
      {
      int line= ls->linenumber;
      expdesc *e= v;
      //
      FuncState new_fs;
      open_func(ls, &new_fs);
      new_fs.f->lineDefined = line;
      //check(ls, '(');
      //parlist(ls);
      //check(ls, ')');
      chunk(ls);
      check_match(ls, TK_END, TK_FUNCTION, line);
      close_func(ls);
      pushclosure(ls, &new_fs, e);
      }
      return;
    }  //AK: end of patch :)
<<<
    default: {
      primaryexp(ls, v);
      return;
    }

Attached is a small stupid test piece to see it works, and doesn't 
affect the do..end usage elsewhere.

-ak

Attachment: testme.lua
Description: Binary data