Re: help with lua style and syntax

["David Collier" <myshkin@...>]

My colleague has pointed out that for a simple situation where I am
returning an error status and a single value, I can use nil in place of
the value to indicate an error.

But obviously that doesn't work for more return values.

I don't quite understand why the syntax of "if" can't be extended to say
that if it is given a list of values it tests the first one. But maybe
something else would graunch to a halt then.

David 


> *From:* "David Collier" <myshkin@cix.co.uk>
> *To:* <lua-l@lists.lua.org>
> *Date:* Thu, 18 Oct 2012 13:18 +0100 (BST)
> 
> in C I can write:
> 
>   if ( passed = myFunction( x , y , &z ) )
>        && ( passed = mySecondFunction( z, &q ) )
>   
> which is preferable to
> 
>   passed = function(x, y, &z)
>   if ( passed )
>   {
>       passed = mySecondFunction( z, &q ) )
>   
> ---------------------------
> Now Lua allows me to return more than one value, so I can write
> 
>   passed, z = myFunction(x, y)
>   
> but is there any way in Lua I can write
> 
>   if passed, z = myFunction(x, y)
>   
> and set both passed and z, but then test 'passed' ??
> 
> It would allow me to do:
> 
>   if     ( passed, z = myFunction(x, y) )
>      and ( passed, q = mySecondFunction(z) )
>      and ( passed, result = myThirdFunction(q) )
> 
> which is a lot more comapct than what I'm writing at present.
>  
> 
>