FW: [NEW:V4MD] Symbols handling

[Ruslan Zasukhin]

> 
> Symbols support added in V4MD so now users will
> be able to use named constants (symbols) - like #kServer - instead of
> meaningless number 2.
> 
> Also kernel errors now expressed as symblos too.
> So instead of testing for meaningless error code like
> 
>   if ValentinaError() = 2 then
>       ...
>   end if
> 
> users can now write
> 
>   if ValentinaErrorIs(#ERR_OS_FILE_NOT_FOUND) then
>       ...
>   end if

This is just great!


> (I do not remember whether mapping system errors into Valentina errors
> was already done but we can already use such syntax).

Some OS errors was wrapped by our codes, but still there is work here.


> Also one more new function added to get last error symbol:
>   ValentinaErrorSymbol()

> Currently this function returns error symbol as string.

> (I cannot force it to return symbol - I've asked about this
> on the Macromedia list).

ok

> But now we can also write:
>   
>   ValentinaInit("", 8 * 1024 * 1024, "", "")
>   
>   set err = ValentinaErrorSymbol()
>   if( symbol(err) = #ERR_SUCCESS ) then
>       alert("OK")
>   end if
> 
> and this works.

Igor, first of all we must find solution to return symbols.
Above example is not good, because it have different syntax.


> May be we need to choose only one syntax form to use in V4MD?
> I mean choose between
>   ValentinaErrorSymbol() (this comes to my mind later)
> and 
>   ValentinaErrorIs()?

Yes, if we will be able return symbols then I prefer

    Valentina.DoSomething()

    if( ValentinaError() != #ERR_SUCCESS )


Interesting, can 2 Xtras in the same project conflict if they use the same
symbol? Please ask on Xtra list.


> As for me first form is more native and it has advantage over
> second form: if user wrote #ERR_SACCESS (instead of #ERR_SUCCESS)
> he/she easily can see this in the debugger and correct the code.
> With second form he/she cannot do this.
>