OpenEuphoria

Re: Deck of Cards Question...

• Posted by Derek Parnell <derekp at solace.com.au> Nov 21, 2000
• 421 views

>-----Original Message-----
>From: George Henry [mailto:ghenryca at hotmail.com]

>How does Euphoria encourage global variables? I don't feel
>encouraged to use
>them, except as simple control flags where "ctrl_flag=1" is equivalent to,
>but more straightforward than, "set_ctrl_flag()" (and similarly for
>"ctrl_flag=0" vs. "clear_ctrl_flag()").

I must admit that I said this just to see if somebody would bite. Euphoria
is not much different than most other languages in its encouragement of
global-scoped variables.

The one situation where I'm forced to make the scope of a variable larger
than required, is when a routine needs to use the value of variable that is
only used by the routine, and was set by an earlier invocation of the
routine. For example...

    integer CurVal CurVal = 0
    function xyz(atom cmd)
        integer temp
        if cmd = 0 then
            CurVal = rand(100)
        else
            temp = rand(cmd)
            if temp > CurVal then
               CurVal = temp
            end if
        end if

        return CurVal
    end function

If this function is inside a file with lots of others, then "CurVal" is
exposed. If I put this function in its own include file and make xyz() a
global function, I then have to be aware of potential name clashes with
other (future) include files.

>Euphoria itself encourages me to use the function method. Euphoria doesn't
>let one pass a reference or pointer, so "append(seq1, seq2)"
>wouldn't do the
>job as a statement, it has to be a function, and following that
>model makes
>sense and is good practice.

True it does. And won't it be nice when Robert allows pseudo
pass-by-reference so that we can reduce typing such that

    append(&seq1, seq2)

is syntactically identical to

    seq1 = append(seq1, seq2)

Hey!, I can dream can't I 

-----
cheers,
Derek Parnell