OpenEuphoria

Re: [Windows] Associate file extensions with a program

• Posted by Derek Parnell <ddparnell at bigpond.com> Oct 12, 2004
• 488 views

Juergen Luethje wrote:

[snip]
> 
> I'd be interested in your opinion about the following two
> implementations.
> 
> }}}
<eucode>
> -- Implementation #1
> integer ErrNo
> ErrNo = 0                -- no error at the beginning
> 
> procedure proc1()
>    if <some error> then
>       ErrNo = 27
>    elsif <another error> then
>       ErrNo = 5
>    else
>       ErrNo = 0
>    end if
> end procedure
> 
> procedure proc2()
>    if <some error> then
>       ErrNo = 3
>    elsif <another error> then
>       ErrNo = 22
>    else
>       ErrNo = 0
>    end if
> end procedure
> 
> proc1()
> proc2()
> </eucode>
{{{

> 
> I think here is a problem, when there is an error in proc1(), and no
> error in proc2(). proc2() then will clear the variable 'ErrNo', and the
> information about the error in proc1() is lost.
> 
> }}}
<eucode>
> -- Implementation #2
> integer ErrNo
> ErrNo = 0                -- no error at the beginning
> 
> procedure proc1()
>    if <some error> then
>       ErrNo = 27
>    elsif <another error> then
>       ErrNo = 5
>    end if
> end procedure
> 
> procedure proc2()
>    if <some error> then
>       ErrNo = 3
>    elsif <another error> then
>       ErrNo = 22
>    end if
> end procedure
> 
> proc1()
> proc2()
> </eucode>
{{{

> 
> The same as above, but without
>    else ErrNo = 0.
> In this case, 'ErrNo' never will be cleared, and it always holds the
> number of the last error that occured.
> 
> I can see that implementation #1 is not a good idea, but what about
> implementation #2?

Well we are using Euphoria so why not take advantage of that?

sequence ErrNo
 ErrNo = {}                -- no error at the beginning
 
 procedure proc3()
    if <some error> then
       ErrNo &= {{"proc3",7}}
    elsif <another error> then
       ErrNo &= {{"proc3",8}}
    end if
 end procedure
 
 procedure proc1()
    if <some error> then
       ErrNo &= {{"proc1",27}}
    elsif <another error> then
       ErrNo &= {{"proc1",5}}
    end if
 end procedure
 
 procedure proc2()
    proc3()
    if <some error> then
       ErrNo &= {{"proc2",3}}
    elsif <another error> then
       ErrNo &= {{"proc2",22}}
    end if
 end procedure

 ErrNo = {} 
 proc1()
 proc2()
 for i = 1 to length(ErrNo) do
    if equal("proc1", ErrNo[i][1]) then
          . . . 
    elsif equal("proc2", ErrNo[i][1]) then
        . . .
    elsif equal("proc3", ErrNo[i][1]) then
        . . .
    end if
 end for

-- 
Derek Parnell
Melbourne, Australia