Is possible to define various methods at same time?

ruby-talk
1

Hi, is possible to define various methods in a single declaration? something
as:

  def method1, method2 (args)
    ...
  end

Of course the above doesn't work, anyway to do it?

Thanks.

···

--
Iñaki Baz Castillo

2

Iñaki Baz Castillo wrote:

Hi, is possible to define various methods in a single declaration?

something

as:

  def method1, method2 (args)
    ...
  end

Of course the above doesn't work, anyway to do it?

Thanks.

Have you looked at #method_missing, and it's relatives, like
#instance_variable_set?

- --
Phillip Gawlowski
Twitter: twitter.com/cynicalryan

~ It takes an uncommon mind to think of these things.
~ --- Calvin

3

Hi,

At Sun, 6 Apr 2008 22:54:52 +0900,
Iñaki Baz Castillo wrote in [ruby-talk:297234]:

Hi, is possible to define various methods in a single declaration? something
as:

  def method1, method2 (args)
    ...
  end

Of course the above doesn't work, anyway to do it?

Do you want alias?

  def method1(args)
    ...
  end
  alias method2 method1

···

--
Nobu Nakada

4

Ok, but my purpose was in fact:

  def method1, method2 (args)
    ...
    super <-- so it call to "method1" or "method2" depending
    ...
  end

I will try what you suggest. Thanks.

···

El Domingo, 6 de Abril de 2008, Phillip Gawlowski escribió:

Have you looked at #method_missing, and it's relatives, like
#instance_variable_set?

--
Iñaki Baz Castillo

5

I don't think aliases are valid for me since I want each method call "super"
(inheritance):

            def debug(log_zone, msg) super(formatter(log_zone, msg)) end
            def info(log_zone, msg) super(formatter(log_zone, msg)) end
            def warn(log_zone, msg) super(formatter(log_zone, msg)) end
            def error(log_zone, msg) super(formatter(log_zone, msg)) end
            def fatal(log_zone, msg) super(formatter(log_zone, msg)) end
            def unknown(log_zone, msg) super(formatter(log_zone, msg)) end

And I want:

            def debug,info,war,error,fatal,unknown(log_zone, msg)
                   super(formatter(log_zone, msg))
            end

Thanks a lot.

···

El Lunes, 7 de Abril de 2008, Nobuyoshi Nakada escribió:

Hi,

At Sun, 6 Apr 2008 22:54:52 +0900,

Iñaki Baz Castillo wrote in [ruby-talk:297234]:
> Hi, is possible to define various methods in a single declaration?
> something as:
>
> def method1, method2 (args)
> ...
> end
>
> Of course the above doesn't work, anyway to do it?

Do you want alias?

  def method1(args)
    ...
  end
  alias method2 method1

--
Iñaki Baz Castillo

6

Here's one way you might go about that:

class Parent
   def example1
     puts "In example 1."
   end

   def example2
     puts "In example 2."
   end
end

class Child < Parent
   %w[1 2].each do |suffix|
     define_method("example#{suffix}") do
       puts "Forwarding to example #{suffix}..."
       super
     end
   end
end

c = Child.new
c.example1
c.example2

__END__

Hope that helps.

James Edward Gray II

···

On Apr 6, 2008, at 9:56 AM, Iñaki Baz Castillo wrote:

El Domingo, 6 de Abril de 2008, Phillip Gawlowski escribió:

Have you looked at #method_missing, and it's relatives, like
#instance_variable_set?

Ok, but my purpose was in fact:

  def method1, method2 (args)
    ...
    super <-- so it call to "method1" or "method2" depending
    ...
  end

7

How about something like this?

class CustomLogger
  def initialize(*args)
    @logger = Logger.new(*args)
  end

  def method_missing(name, *args)
    case :debug, :info, :warn, :error, :fatal, :unknown
      @logger.send name, formatter(*args)
    else
      @logger.send name, *args
    end
  end

  def formatter(log_zone, msg)
    # Do your formatting here
    ...
  end
end

=Gennady.

···

-----Original Message-----
From: Iñaki Baz Castillo [mailto:ibc@aliax.net]
Sent: Monday, April 07, 2008 1:40 PM
To: ruby-talk ML
Subject: Re: Is possible to define various methods at same time?

El Lunes, 7 de Abril de 2008, Nobuyoshi Nakada escribió:
> Hi,
>
> At Sun, 6 Apr 2008 22:54:52 +0900,
>
> Iñaki Baz Castillo wrote in [ruby-talk:297234]:
> > Hi, is possible to define various methods in a single declaration?
> > something as:
> >
> > def method1, method2 (args)
> > ...
> > end
> >
> > Of course the above doesn't work, anyway to do it?
>
> Do you want alias?
>
> def method1(args)
> ...
> end
> alias method2 method1

I don't think aliases are valid for me since I want each
method call "super"
(inheritance):

            def debug(log_zone, msg)
super(formatter(log_zone, msg)) end
            def info(log_zone, msg)
super(formatter(log_zone, msg)) end
            def warn(log_zone, msg)
super(formatter(log_zone, msg)) end
            def error(log_zone, msg)
super(formatter(log_zone, msg)) end
            def fatal(log_zone, msg)
super(formatter(log_zone, msg)) end
            def unknown(log_zone, msg)
super(formatter(log_zone, msg)) end

And I want:

            def debug,info,war,error,fatal,unknown(log_zone, msg)
                   super(formatter(log_zone, msg))
            end

Thanks a lot.

--
Iñaki Baz Castillo

8

How about something like this?

class CustomLogger
  def initialize(*args)
    @logger = Logger.new(*args)
  end

  def method_missing(name, *args)
    case :debug, :info, :warn, :error, :fatal, :unknown
      @logger.send name, formatter(*args)
    else
      @logger.send name, *args
    end
  end

  def formatter(log_zone, msg)
    # Do your formatting here
    ...
  end
end

=Gennady.

Oops, correction in case usage:

class CustomLogger
  def initialize(*args)
    @logger = Logger.new(*args)
  end

  def method_missing(name, *args)
    case name
      when :debug, :info, :warn, :error, :fatal, :unknown
        @logger.send name, formatter(*args)
      else
        @logger.send name, *args
    end
  end

  def formatter(log_zone, msg)
    # Do your formatting here
    ...
  end
end

9

Sure, thanks :slight_smile:

···

El Domingo, 6 de Abril de 2008, James Gray escribió:

On Apr 6, 2008, at 9:56 AM, Iñaki Baz Castillo wrote:
> El Domingo, 6 de Abril de 2008, Phillip Gawlowski escribió:
>> Have you looked at #method_missing, and it's relatives, like
>> #instance_variable_set?
>
> Ok, but my purpose was in fact:
>
> def method1, method2 (args)
> ...
> super <-- so it call to "method1" or "method2" depending
> ...
> end

Here's one way you might go about that:

class Parent
   def example1
     puts "In example 1."
   end

   def example2
     puts "In example 2."
   end
end

class Child < Parent
   %w[1 2].each do |suffix|
     define_method("example#{suffix}") do
       puts "Forwarding to example #{suffix}..."
       super
     end
   end
end

c = Child.new
c.example1
c.example2

__END__

Hope that helps.

--
Iñaki Baz Castillo

10

But is "method_missing" a especial keyword? If it's a normal method name then
I will neet to call:
  objetc.method_missing
that I don't want, I need using:
  debug(...), warn(...)...

Thanks.

···

El Lunes, 7 de Abril de 2008, Gennady Bystritsky escribió:

def method_missing(name, *args)

--
Iñaki Baz Castillo

11

Can you explain why you need this? Maybe there is a different
solution altogether. This redundancy in method definitions is
irritating to me and I suspect there might be a better way to achieve
what you really need.

Kind regards

robert

···

2008/4/7, Iñaki Baz Castillo <ibc@aliax.net>:

El Domingo, 6 de Abril de 2008, James Gray escribió:

> Hope that helps.

Sure, thanks :slight_smile:

--
use.inject do |as, often| as.you_can - without end

12

method_missing(), if present, is automatically invoked by Ruby on an attempt to call a method not explicitly defined for an object. So you will be able to write objetc.debug(...), objetc.warn(...), etc.

Gennady.

···

-----Original Message-----
From: Iñaki Baz Castillo [mailto:ibc@aliax.net]
Sent: Monday, April 07, 2008 2:41 PM
To: ruby-talk ML
Subject: Re: Is possible to define various methods at same
time? [Correction]

El Lunes, 7 de Abril de 2008, Gennady Bystritsky escribió:
> def method_missing(name, *args)

But is "method_missing" a especial keyword? If it's a normal
method name then
I will neet to call:
  objetc.method_missing
that I don't want, I need using:
  debug(...), warn(...)...

Thanks.

--
Iñaki Baz Castillo

13

Thanks a lot. Finally it was not so important for me as I thought initially,
so I can avoid using it. I asked that for the following reason:

I'm using CusomLogger class that inherits from Logger class. And I want to
modify some methods, all exactly the same:

    def debug(log_zone, msg) super(formatter(log_zone, msg)) end
    def info(log_zone, msg) super(formatter(log_zone, msg)) end
    def warn(log_zone, msg) super(formatter(log_zone, msg)) end
    def error(log_zone, msg) super(formatter(log_zone, msg)) end
    def fatal(log_zone, msg) super(formatter(log_zone, msg)) end
    def unknown(log_zone, msg) super(formatter(log_zone, msg)) end

As you can see, all the methods body is exactly the same. I expected there
could be a cool way to do something as:

    def debug,info,war,error,fatal,unknown(log_zone, msg)
      super(formatter(log_zone, msg))
     end

just it.

Thanks a lot for your help.

···

El Lunes, 7 de Abril de 2008, Robert Klemme escribió:

Can you explain why you need this? Maybe there is a different
solution altogether. This redundancy in method definitions is
irritating to me and I suspect there might be a better way to achieve
what you really need.

--
Iñaki Baz Castillo

14

Ops, thanks, very interesting :wink:

···

El Lunes, 7 de Abril de 2008, Gennady Bystritsky escribió:

method_missing(), if present, is automatically invoked by Ruby on an
attempt to call a method not explicitly defined for an object. So you will
be able to write objetc.debug(...), objetc.warn(...), etc.

Learn How to Blog and Build Websites for Profit!

--
Iñaki Baz Castillo

15

I agree to Gennady: delegation might be a better choice over inheritance here.

Kind regards

robert

···

2008/4/7, Iñaki Baz Castillo <ibc@aliax.net>:

El Lunes, 7 de Abril de 2008, Robert Klemme escribió:

> Can you explain why you need this? Maybe there is a different
> solution altogether. This redundancy in method definitions is
> irritating to me and I suspect there might be a better way to achieve
> what you really need.

Thanks a lot. Finally it was not so important for me as I thought initially,
so I can avoid using it. I asked that for the following reason:

I'm using CusomLogger class that inherits from Logger class. And I want to
modify some methods, all exactly the same:

                def debug(log_zone, msg) super(formatter(log_zone, msg)) end
                def info(log_zone, msg) super(formatter(log_zone, msg)) end
                def warn(log_zone, msg) super(formatter(log_zone, msg)) end
                def error(log_zone, msg) super(formatter(log_zone, msg)) end
                def fatal(log_zone, msg) super(formatter(log_zone, msg)) end
                def unknown(log_zone, msg) super(formatter(log_zone, msg)) end

As you can see, all the methods body is exactly the same. I expected there
could be a cool way to do something as:

                def debug,info,war,error,fatal,unknown(log_zone, msg)
                        super(formatter(log_zone, msg))
                 end

just it.

--
use.inject do |as, often| as.you_can - without end

16

What you probably want is this:

class CustomLogger < Logger
  %w(debug info warn error fatal unknown).each do |msg|
    eval("def #{msg}(log_zone, msg)\n super(formatter(log_zone, msg))\n end\n")
  end
end

Juilan.

Learn Ruby on Rails! Check out the FREE VIDS (for a limited time) VIDEO #3 out NOW!
http://sensei.zenunit.com/

···

On 08/04/2008, at 6:38 AM, Iñaki Baz Castillo wrote:

El Lunes, 7 de Abril de 2008, Robert Klemme escribió:

Can you explain why you need this? Maybe there is a different
solution altogether. This redundancy in method definitions is
irritating to me and I suspect there might be a better way to achieve
what you really need.

Thanks a lot. Finally it was not so important for me as I thought initially,
so I can avoid using it. I asked that for the following reason:

I'm using CusomLogger class that inherits from Logger class. And I want to
modify some methods, all exactly the same:

    def debug(log_zone, msg) super(formatter(log_zone, msg)) end
    def info(log_zone, msg) super(formatter(log_zone, msg)) end
    def warn(log_zone, msg) super(formatter(log_zone, msg)) end
    def error(log_zone, msg) super(formatter(log_zone, msg)) end
    def fatal(log_zone, msg) super(formatter(log_zone, msg)) end
    def unknown(log_zone, msg) super(formatter(log_zone, msg)) end

As you can see, all the methods body is exactly the same. I expected there
could be a cool way to do something as:

    def debug,info,war,error,fatal,unknown(log_zone, msg)
      super(formatter(log_zone, msg))
     end

just it.

Thanks a lot for your help.

--
Iñaki Baz Castillo

17

PS: I would guess that the original Logger class provides some means
to control formatting, for example a pluggable formatter. Why can't
you use that?

Kind regards

robert

···

2008/4/8, Robert Klemme <shortcutter@googlemail.com>:

2008/4/7, Iñaki Baz Castillo <ibc@aliax.net>:

> El Lunes, 7 de Abril de 2008, Robert Klemme escribió:
>
>
> > Can you explain why you need this? Maybe there is a different
> > solution altogether. This redundancy in method definitions is
> > irritating to me and I suspect there might be a better way to achieve
> > what you really need.
>
>
> Thanks a lot. Finally it was not so important for me as I thought initially,
> so I can avoid using it. I asked that for the following reason:
>
> I'm using CusomLogger class that inherits from Logger class. And I want to
> modify some methods, all exactly the same:
>
> def debug(log_zone, msg) super(formatter(log_zone, msg)) end
> def info(log_zone, msg) super(formatter(log_zone, msg)) end
> def warn(log_zone, msg) super(formatter(log_zone, msg)) end
> def error(log_zone, msg) super(formatter(log_zone, msg)) end
> def fatal(log_zone, msg) super(formatter(log_zone, msg)) end
> def unknown(log_zone, msg) super(formatter(log_zone, msg)) end
>
> As you can see, all the methods body is exactly the same. I expected there
> could be a cool way to do something as:
>
> def debug,info,war,error,fatal,unknown(log_zone, msg)
> super(formatter(log_zone, msg))
> end
>
> just it.

I agree to Gennady: delegation might be a better choice over inheritance here.

--
use.inject do |as, often| as.you_can - without end