Define_method, proc with block?

ruby-talk
1

A little help here. I'm trying to dynamically create a method that passes
through to another method but adds in a fixed argument. Unfortunately I can't
pass a block via a proc. How does one handle this? I ended up having to
create two methods for each wrapped method. Yuk. Here's the code snip:

  # NOTE: wrap_advice is the method/proc used to wrap meth
  # meth is defined in a subclass or singleton, c, to achieve wrapping

  # define the interceptor
  c.class_eval {
    define_method("advice___#{meth}",wrap_advice)
  }
  c.class_eval %Q{
    def #{meth}(*args,&blk)
      target = proc{super} #proc{|*args,&blk| super(*args,&blk)}
      advice___#{meth}(target,*args,&blk)
    end
  }

Notice also I can't pass the block via the proc'd super either. I want to just
do this:

  # define the interceptor
  c.class_eval {
    define_method(meth) {|*args,&blk|
      target = proc{|*args,&blk| super(*args,&blk)}
      wrap_advice.call(target,*args,&blk)
    end
  }

Any ideas?

Thanks,
T.

2

A little help here. I'm trying to dynamically create a method that passes
through to another method but adds in a fixed argument. Unfortunately I can't
pass a block via a proc.

     Why not? Or more lucidly (asfter this post a swear I'm going for
tea): what problems are you having? It seems like either of the methods
that Mauricio

http://www.talkaboutprogramming.com/group/comp.lang.ruby/messages/107894.html

or I (about half way down, search for "$observers")

http://www.talkaboutprogramming.com/group/comp.lang.ruby/messages/107721.html,
suggested on this thread should do the trick.

-- MarkusQ

···

On Fri, 2004-10-01 at 09:08, trans. (T. Onoma) wrote:

How does one handle this? I ended up having to
create two methods for each wrapped method. Yuk. Here's the code snip:

  # NOTE: wrap_advice is the method/proc used to wrap meth
  # meth is defined in a subclass or singleton, c, to achieve wrapping

  # define the interceptor
  c.class_eval {
    define_method("advice___#{meth}",wrap_advice)
  }
  c.class_eval %Q{
    def #{meth}(*args,&blk)
      target = proc{super} #proc{|*args,&blk| super(*args,&blk)}
      advice___#{meth}(target,*args,&blk)
    end
  }

Notice also I can't pass the block via the proc'd super either. I want to just
do this:

  # define the interceptor
  c.class_eval {
    define_method(meth) {|*args,&blk|
      target = proc{|*args,&blk| super(*args,&blk)}
      wrap_advice.call(target,*args,&blk)
    end
  }

Any ideas?

Thanks,
T.

3

> A little help here. I'm trying to dynamically create a method that passes
> through to another method but adds in a fixed argument. Unfortunately I
> can't pass a block via a proc.

     Why not? Or more lucidly (asfter this post a swear I'm going for
tea): what problems are you having? It seems like either of the methods
that Mauricio

http://www.talkaboutprogramming.com/group/comp.lang.ruby/messages/107894.ht

ml

Ah, thank you. Thank you. Yes, this first example is essentially what I'm
doing. I see from it that block parameters in Procs are taken care of in
1.9+, I just need to update.

or I (about half way down, search for "$observers")

http://www.talkaboutprogramming.com/group/comp.lang.ruby/messages/107721.ht
ml, suggested on this thread should do the trick.

No aliasing for me thanks. But I am curious, is Symbol.uniq new to 1.9?

Thanks Again,
T.

···

On Friday 01 October 2004 01:42 pm, Markus wrote:

On Fri, 2004-10-01 at 09:08, trans. (T. Onoma) wrote:

4

Ah, thank you. Thank you. Yes, this first example is essentially what I'm
doing. I see from it that block parameters in Procs are taken care of in
1.9+, I just need to update.

     Actually, if you &-ize it on the way in you should be fine in 1.8
(at least, it works transparently for me).

> or I (about half way down, search for "$observers")
>
> http://www.talkaboutprogramming.com/group/comp.lang.ruby/messages/107721.ht
>ml, suggested on this thread should do the trick.

No aliasing for me thanks. But I am curious, is Symbol.uniq new to 1.9?

Oops. Sorry, it's from my personal bag o'tricks (another ported
lisp-ism):

class Symbol
    @@unique_sym_counter = 0
    def Symbol.unique(prefix="gloop")
        prefix =
          prefix.to_s.
          gsub(/\+/,'_plus_').
          gsub(/\*/,'_times_').
          gsub(/-/,'_minus_').
          gsub(/\//,'_div_').
          gsub(/\!/,'_bang_')
        return ("#{prefix.to_s}__#{@@unique_sym_counter += 1}").intern
        end
    end

So, I'm curious right back: why the aversion to aliasing?

-- MarkusQ

···

On Fri, 2004-10-01 at 11:22, trans. (T. Onoma) wrote:

5

Simple: method namespace clutter.

T.

···

On Friday 01 October 2004 03:05 pm, Markus wrote:

So, I'm curious right back: why the aversion to aliasing?

6

*smile* I used to have that problem with my web browser cache
directory--it kept getting cluttered up with all these files with
cryptic names. It was annoying the tar out of me. Then I decided to
try a trick I'd developed with my mail spool directory: I stopped
looking in there.

     That cleared the problem right up.

-- MarkusQ

···

On Fri, 2004-10-01 at 12:17, trans. (T. Onoma) wrote:

On Friday 01 October 2004 03:05 pm, Markus wrote:
> So, I'm curious right back: why the aversion to aliasing?

Simple: method namespace clutter.

7

LOL! :slight_smile: Yea, well, there is that.

T.

···

On Friday 01 October 2004 04:06 pm, Markus wrote:

On Fri, 2004-10-01 at 12:17, trans. (T. Onoma) wrote:
> On Friday 01 October 2004 03:05 pm, Markus wrote:
> > So, I'm curious right back: why the aversion to aliasing?
>
> Simple: method namespace clutter.

     *smile* I used to have that problem with my web browser cache
directory--it kept getting cluttered up with all these files with
cryptic names. It was annoying the tar out of me. Then I decided to
try a trick I'd developed with my mail spool directory: I stopped
looking in there.

     That cleared the problem right up.