RE: Lua code generation and optimisation

["Thijs Schreijer" <thijs@...>]

> From: lua-l-bounces@lists.lua.org [mailto:lua-l-bounces@lists.lua.org]
> On Behalf Of steve donovan
> Sent: woensdag 3 oktober 2012 15:26
> To: myshkin@cix.co.uk; Lua mailing list
> Subject: Re: Lua code generation and optimisation
> 
> On Wed, Oct 3, 2012 at 3:13 PM, David Collier <myshkin@cix.co.uk>
> wrote:
> > won't # if fred == nil then
> > fulfil the purpose?
> 
> That would be the syntax, yes - and 'fred == nil' there is a _compile-
> time_ value, which could be anything. Or you could have a big shouting
> IF.
> 
> > Indeed - I am thinking ahead to trying to get a worthwhile size of
> > program inside a single-chip-micro
> 
> Then I fully understand. I'll experiment with classic if/ifelse/else
> macros in LM
> 
> steve d.

Trickiest part is whether you want the code to run 'un-preprocessed' as well

#IF something
    print("something")
#ELSE
    print("something else")
#ENDIF

This will clearly fail, won't compile. If you mark with --# it will run but
incorrect, as it executes both lines

--#IF something
    print("something")
--#ELSE
    print("something else")
--#ENDIF

Now if you can make the IF ELSE switch based on --# as in

--#IF something
    print("something")
--#ELSE
--#    print("something else")
--#ENDIF

It will also run on un-preprocessed, only if preprocessed  with 'something'
set, the 'something else' line would become available

Thijs