From: Aamer Akhter <aakhter@...>
Date: 2003-10-02T05:02:23+09:00
Subject: Re: tcltklib and not init'ing tk


Nice to see a fellow industry member dealing with the same problem ;-)

On 10/1/03 10:06 AM, in article
20031001140652.GA29212@vor-lord.ftc.agilent.com, "Brett H. Williams"
<brett_williams@agilent.com> wrote:

> On Oct  1, Aamer Akhter wrote:
>> Hello,
>> 
>> I'm using the tcltklib extension in ruby 1.8. It seems to be working
>> well for my transition from tcl. There are a couple of stumbling
>> blocks I'm running into:
>> 
>> 1) is there a way to _not_ start tk? When I create a new interpreter
>> (let's say from a non X-fwded ssh session) it may cause a failure. I'm
>> only interested in Tcl.
> 
> This is a big pain for me as well.  I would really like to have this fixed,
> as Ruby/Tcl interaction is important to me.  But it hasn't been a big
> enough pain to try and hack around in the C code :) (yet)

I'm more than willing to spend some time on this. But I'm new to ruby, and
to the tcl-C portions.

It seems like the thing to do is be able to pass the desire for no tk in via
the new call:

TclTkIp.new(notk => 1),

It looks like tcltklib.c:ip_init() gets called. The current parameters wind
up being plugged into Tcl's argv0 and args. So, in keeping with the current
implementation perhaps something like:

TclTkIp.new($argv0, $args, 1) would be "better"

Where 1 represents the non-desire to load Tk.

One would need to skip over when 1 is set.:

    /* from Tcl_AppInit() */
    DUMP1("Tk_Init");
    if (Tk_Init(ptr->ip) == TCL_ERROR) {
    rb_raise(rb_eRuntimeError, "%s", ptr->ip->result);
    }
    DUMP1("Tcl_StaticPackage(\"Tk\")");
#if TCL_MAJOR_VERSION >= 8
    Tcl_StaticPackage(ptr->ip, "Tk", Tk_Init, Tk_SafeInit);
#else
    Tcl_StaticPackage(ptr->ip, "Tk", Tk_Init,
              (Tcl_PackageInitProc *) NULL);
#endif


>> 2) Is there a japanese to english translation of
>> ext/tcltklib/MANUAL.euc? Or can somebody point to a tool that I may
>> use to do the translation? babelfish.altavista  does not appear to
>> work.
> 
> I've done all of my work without any kind of documentation in English.
> There just doesn't seem to be that strong an interest in mixing Ruby and
> Tcl (we are some of the exceptions).  The tcltklib extension was written
> for Ruby/Tk.  Access to the Tcl interpreter through it is a side effect--a
> highly useful side effect for me and you, but nevertheless not really
> what was intended by the developers.  So using the Tcl interpreter from
> Ruby, and vice versa, is probably not even well documented in Japanese
> (someone please correct me if I am wrong).
> 
>> 3). Are there any examples of ruby methods being called from the tcl
>> code running inside the interpreter?
> 
> This is how I do it:
> 
> set somevar [ruby "some_method()"]
> 
> You can put any ruby code as the argument to the 'ruby' proc.  You _must_,
> however, make sure that the return value of the ruby code is a string, or
> things will crash.

;-) yeah. I already ran into that. I've been using the ruby_fmt proc that
tcltk creates on init. That's just a wrapper for calling the ruby tcl
command.

> 
> You likely will have to do some creative things to get the scope that you
> want--Tcl can only communicate directly with class or global variables.
> This means if you call out to Tcl from Ruby, you will not have access to
> instance or local variables.  It makes perfect sense, but typically
> requires doing some non-rubyish things to get access to what you need in
> Tcl.

I don't think the importance of the above has sunk in yet. Do you mean to
say that in a class, I won't be able to do something like:

Ip._eval("puts #{var}")