From: Robert Klemme <bob.news@...>
Date: 2004-07-03T00:42:47+09:00
Subject: Re: Extending The File Class


"Brad" <BCoish@Dymaxion.com> schrieb im Newsbeitrag
news:zgeFc.15584$vO1.103757@nnrp1.uunet.ca...
> All:
>
> I'm currently working on the OpenVMS platform and would like to
> write an extension library that would encapsulate the different
> OpenVMS file types (of which there are several beyond text and
> binary).
>
> What needs to be done is to pass additional parameters to the
> underlying C api's fopen.  fopen on OpenVMS contains parameters
> not supported by the ANSI standard.  The extra parameters are
> used to open the various file formats supported by OpenVMS.
>
> My thoughts are to:
> 1) Create a new class that inherits from the File class and simply
>    overload/override the open/new command.
> 2) Add new methods to the File class that support the parameters
>    that I neeed to pass through (still requires access to the
>    underlying C API)
> 3) Overload the open/new in File directly to allow optional parameters
>    to be passed through.

I'd go for 1) if the functionality is extremely special (I don't know
OpenVMS so it's up to others to judge).  If that's not the case (i.e.
functionality can reasonably be expected of other OS's, too) I'd do 3) and
implement it on other platforms to either ignore flags or raise an error.
Whatever is more appropriate.

2) is the worst solution IMHO since File is cross platform but those added
methods seem to be too special (i.e. only meaningfil on OpenVMS).

Kind regards

    robert


> My question is:
>  - What needs to be done?  I can figure out how to write a class using
>    the RAPI, but I'm not sure about what Ruby does behind the scenes
>    (i.e. internal states,etc)
>    Note: Only the open/new is required to be modified, all other
>          file I/O routines work the same as in ANSI C.
>
> Any help would be appreciated.
>
> Regards,
> Brad