[M3devel] quake and/or "short circuit"

[hendrik at topoi.pooq.com]

On Wed, Aug 18, 2010 at 01:17:02AM +0000, Jay K wrote:
> 
> I don't know what the names should be, I'm pretty comfortable with "&&" and "||".
> Short circuiting is very useful.
>  
> > Dijkstra advises against it, though.
> 
> That makes me question Dijkstra, not short circuiting.

He has specific reasons, having to do with programs being part of a 
logical calculus.  In logic, 'and' and 'or' are both commutative, so he 
thinks it sim0plifies the formal calculus of programming to have them 
behave the same in programs.

>  
>  
> Also useful is assignment being an expression.
> I wish it was in Modula-3.

So do I.

>  
> Such things as:
>  
>  
> if ((f = fopen(..)) && fread(f,...)
>  
>  
> or if (p && *p)
>  
>  
> In the first case Modula-3 forces useless verbosity and indentation.
> In the second case Modula-3 gets it right but Quake fails.
>  
> Lacking these features you end up contorting your code one way or another, such as duplicating things.
>  
>  
> I really can't stand code that looks like:
>  
>  
> result = do something
>    if success(result)
>    do more stuff
>    if success
>       do more stuff
>       if succes
>         do more stuff
>  
>  
> Modula-3 this wrong.
> Exceptions help.
> But basically I want to be able to introduce WITH or VAR anywhere, but not need to "END" them, and therefore no implied need for indentation..

It looks as if you want Modula 3 with Algol 68 syntax.
So do I.

-- hendrik