OpenEuphoria

RE: Eu's poor design

• Posted by Andreas Rumpf <pfropfen at gmx.net> Aug 17, 2003
• 467 views

jbrown105 at speedymail.org wrote:
> 
> 
> On Sun, Aug 17, 2003 at 07:41:01PM +0000, Andreas Rumpf wrote:
> > 
> > 
> > > (making a stack in Eu is easy)
> > Let's see the stack in Eu:
> > 
> > sequence stack
> > stack = {}
> > 
> > function push(sequence stack, object item)
> >   return stack = append(stack, item)
> 
> this is wrong, btw. should be:
> 
> stack = append(stack, item)
> return stack
Yes, as I said I should stop coding in topica windows.
> 
> > end function
> > 
> > function pop(sequence stack) -- returns stack without top
> 
> No, the pop removes the top of the stack, and then returns the part it
> removed.
Not necessarily.
> 
> >   return stack[1..length(stack)-1]
> > end function
> > 
> > function topOfStack(sequence stack)
> >   return stack[length(stack)]
> > end function
> > 
> > Yes, quite easy. But what if I want to make it easier and more 
> > efficient? (Using push()/pop() that modify the stack directly!) Guess 
> > what, it can't be done in Eu.
> 
> Wrong.
> 
> sequence stack
> stack = {}
> 
> procedure push(object item)
> 	stack = append(stack, item)
> end procedure
> function pop()
> 	object item
> 	item = stack[length(stack)]
> 	stack = stack[1..length(stack)-1]
> 	return item
> end function	
> 
> or with your version of pop() and topOfStack() (which is wrong btw)
> 
> function pop()
> 	return stack[1..length(stack)-1]
> end function
> function topOfStack()
> 	return stack[length(stack)]
> end function

So, you used a global variable... (And proved one of my earlier 
posts...) What if I want to have 2 different stacks? - Use a sequence of 
stacks and pass the routines the index of the stack to work with. This 
is a solution. But it simulates pbr! So why not have it directly?

> > Again, in Pascal/C/etc. I have choice how to implement certain things!
> > You can't even write a swap() routine, because of lack of pbr!
> 
> Well C has no pbr. It has simulated pbr via pointers.
Ok, forget about C. What about Basic/Ada/C++?
> 
> Yes, the inability to have a swap() routine is annoying. Very much so.
> Of course this could also be solved via macros ...
> 
> object tmp
> macro swap(a,b) tmp = a a = b b = tmp
> ...
> swap(var_one, var_two)
> 
> but only because the macro is rewritten as
> 
> tmp = var_one var_one = var_two var_two = tmp
> 
> so even the macro simulates pass-by-reference!
Let's implement a macro facility instead of pbr! (Irony)