OpenEuphoria

RE: pass by reference Karl

• Posted by kbochert at ix.netcom.com Feb 12, 2002
• 481 views

-------Phoenix-Boundary-07081998-

Hi Bernie Ryan, you wrote on 2/12/02 1:20:32 PM:

>
>Karl:
>  What happens when a user does slicing, append, prepend
>  on the sequence that is passed. Don't forget that
>  sequences are dynamic and are reallocated dynamically.
>Bernie
>

Thanks for pointing that out -- I had overlooked it totally.
The good news is that I have now managed to correct the
slicing case:
   procedure foo (sequence s)
     s = s[3..]
   end procedure

   sequence t = "Hello"
   foo (!!t)
   ?t       -- => "llo"

Time and again I run into these issues that seem to
be killers, only to discover that the code to do
them seems to be already there. I think Rob did NOT
choose pass-by-value because it was the easy
choice for implementation.

My motivation for adding pass-by-value is to allow
class methods to be passed a 'this reference' which
refers to the instance to be modified. My original
implementation accomplishes this nicely because no
class method ever changes the structure of the instance.

Given the ease of handling slices, I suspect that
all cases could be handled, but the risk of deep
problems grows, so I am somewhat reluctant to
proceed.

Thanks for the bug find
Karl

-------Phoenix-Boundary-07081998---