Re: use of assert in Java [vs. exceptions]

"Giovanni Azua" <bravegag@hotmail.com> writes:


  I have two thoughts on this.

  1.) Assume ?div(x,y)? had undefined behaviour when y == 0,
  and we wanted to do this in an application:

for( x = 0; x < HUGE; ++x )div( x, y );

  The application knows that in the case of y being 0, the
  best thing to do is ?f()?, so

if( y )for( x = 0; x < HUGE; ++x )div( x, y ); else f();

  . We can see that it is sufficient to do the test /once
  outside of the loop/ for a primitive variable ?y? in a
  single-threaded application. If the test would be done
  inside of ?div? instead, it would not be possible to move
  it outside of the loop.

  2.) Assume ?div(x,y)? had undefined behaviour when y == 0.
  One can always write a wrapper ?defensiveDiv(x,y)? that has
  defined behaviour for y == 0 and otherwise the same behavior
  as ?div(x,y)?, while it might be slower than ?div(x,y)?.

  On the other hand, given only ?defensiveDiv(x,y)? it is not
  possible to write a wrapper to get the behavior and run-time
  properties of ?div(x,y)?.