Re: function foo() in table

[Sean Conner <sean@...>]

It was thus said that the Great Dirk Laurie once stated:
> 2014-04-21 23:33 GMT+02:00 Sean Conner <sean@conman.org>:
> > It was thus said that the Great Coroutines once stated:
> >>
> >> I always remember that local function f() ... end is equivalent to
> >> local f; f = function () ... end because when I have to write
> >> recursive functions it errors when it tries to call the
> >> not-yet-declared identifier from within itself.
> 
> s/errors/would otherwise error/
> 
> >   You should try using the Y combinator.
> >
> > function Y(f)
> >   local function g(...) return f(g,...) end
> >   return g
> > end
> >
> > print(Y(function(rec, x)
> >           if x < 2 then
> >             return 1
> >           else
> >             return x * rec(x-1)
> >           end
> >         end)(5))
> >
> >   -spc (Unfortunately, do declare Y with your conding standard requres the
> >         use of Y ... )
> 
> I don't understand the very last point made, even after correcting two typos.

  You originally stated:
  
> I have stopped using "local function f()" because I cannot remember
> whether it is the same as "local f = function()" or "local f;
> f=function()". So whichever of those I need, I code explicitly.

  Coroutines was stating that
  
	local function f() ... end
	
is the same as:

	local f
	f = function() ... end
	
because otherwise, you couldn't write recursive functions if

	local function f() ... end
	
was equivalent to:

	local f = function() ... end
	
  In a way, you could think of 

	function draw(x1,y1,x2,y3) ... end

as doing

	draw = -- some place holding value
	draw = function(x1,y1,x2,y2)

which also means that

	local function draw(x1,y1,x2,y2) ... end

follows that pattern:

	local draw = -- some place holding value
	draw = function(x1,y1,x2,y2) ... end

  The whole bit I added with the Y combinator was just a riff on the
conversation.  You can think of the Y combinator as allowing a anonymous
(non-named) function to call itself (the actual description uses some obtuse
mathematical terms like "fixed point"---I don't pretend to understand what
exactly it means).  

  -spc (I hope that cleared that up ... )