• Alex Burton <alexibu mac.com> Mar 05 2009

Alex Burton <alexibu mac.com> writes:

Walter Bright Wrote:

When I see code like this I see bugs.

 
 Foo f;
 if (x < 1) f = new Foo(1);
 else if (x >= 1) f = new Foo(2);
 f.member();
 


This should not compile IMHO default non nullable is necessary.
If using a language with default nullable, I would write this as 
Foo generateFoo()
{
    if (x < 1) return new Foo(1);
    else if (x >= 1) return new Foo(2);
}
This way the compiler has to check that there is a returned value for each path.
As the conditions become more complex, the compiler enforcing a return value
prevents the result from being null (unless of course you return 0 just to
prove a point)

 Foo f;
 bar(&f);
 
 ? Or in another form:
 
 bar(ref Foo f);
 Foo f;
 bar(f);
 
 Java doesn't have ref parameters.


Same problem.
The prototype of bar should be Foo bar() if the intent of bar is to return a
reference to an instance of Foo. Returning what is conceptually the result of a
function in by ref parameters is really nasty way to code IMHO.

Alex