OpenEuphoria

Re: New keyword added: continue

• Posted by Derek Parnell <ddparnell at bi?po?d.com> May 28, 2008
• 779 views

Kat wrote:
> 
> c.k.lester wrote:
> > Maintainability of code is of utmost importance. Using goto is dangerous! :)
> 
> Why are these two blocks so different that you call the 2nd one "dangerous"
> ?

Because in the first one we could get this ...
 
 

procedure foo()
  --- many lines of code ---
  goto next
  --- many lines of code ---
  goto next
  --- many lines of code --- 
  for loop = 1 to x do
    -- code
    if x = blah then goto next end if
    -- code
    :next
  end for
  --- many lines of code ---
  goto next
  --- many lines of code --- 
end procedure

 
But I can't do that in the second example, and thus the cost of maintenance is
lower in the second example. The cost is affected by the probability of bugs, the
amount of code to read, and the amount of coding to repair/enhance existing code.

> And how would you know how many places called "exit" to make the
> code flow change?

The problem is not the 'goto' statement (ie. change of control flow), the
problem is with the label and how to arrive there.

The extra maintenance cost that 'goto' introduces into a program must be offset
by the performance benefit derived from using it, IMHO. Demonstrate that in a
specific piece of Euphoria code and I'll support the use of 'goto' in that piece
of code.

-- 
Derek Parnell
Melbourne, Australia
Skype name: derek.j.parnell