# Re: prototype design pattern

**URL:** <https://www.ruby-forum.com/t/re-prototype-design-pattern/98110>\
**Category:** Ruby\
**Created:** [July 12, 2006, 4:46pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110 "2006-07-12T16:46:06Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 12, 2006, 4:46pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/1 "2006-07-12T16:46:06Z")

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> regards.
> 
> -a

Hm, it’s not at  
[http://wiki.rubygarden.org/Ruby/page/show/ExampleDesignPatternsInRuby](http://wiki.rubygarden.org/Ruby/page/show/ExampleDesignPatternsInRuby)

Anyway, it looks to me like some combination of .clone plus a factory.  
I’m not sure there’s any real savings in Ruby to doing things this way,  
but I’d be happy to be proved wrong.

Regards,

Dan

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**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 12, 2006, 5:09pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/2 "2006-07-12T17:09:09Z")

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On Wed, 12 Jul 2006, Berger, Daniel wrote:

> Hm, it’s not at  
> [http://wiki.rubygarden.org/Ruby/page/show/ExampleDesignPatternsInRuby](http://wiki.rubygarden.org/Ruby/page/show/ExampleDesignPatternsInRuby)

> **[Prototype-based programming](https://en.wikipedia.org/wiki/Prototype-based_programming)**
>
> Prototype-based programming is a style of object-oriented programming in which behaviour reuse (known as inheritance) is performed via a process of reusing existing objects that serve as prototypes. This model can also be known as prototypal, prototype-oriented, classless, or instance-based programming.
> Prototype-based programming uses the process generalized objects, which can then be cloned and extended. Using fruit as an example, a "fruit" object would represent the properties and functionali...

> Anyway, it looks to me like some combination of .clone plus a factory. I’m  
> not sure there’s any real savings in Ruby to doing things this way, but I’d  
> be happy to be proved wrong.

hi daniel-

savings is only keystrokes. but it can very elegant looking and, these  
days,  
ruby coding bores me unless it looks good too - solving problems is just  
too  
easy in it to provide enough challenge! 😉 take this code for  
example:

```
 fortytwo :~/eg/ruby/prototype > cat a.rb
 require 'prototype'

 singleton = Prototype.new{
   @a, @b = 40, 2

   def answer() @a + @b end
 }

 p singleton.answer

 fortytwo :~/eg/ruby/prototype > ruby a.rb
 42

 fortytwo :~/eg/ruby/prototype > cat b.rb
 require 'prototype'

 DB = Prototype.new{
   host 'localhost'
   port 4242

   def connect() 'do something' end

   def inspect() [host, port].join ':' end
 }

 p DB
 p DB.host
 p DB.port

 fortytwo :~/eg/ruby/prototype > ruby b.rb
 localhost:4242
 "localhost"
 4242

```

do you like the look of it?

i’ll post my impl in a follow-up.

cheers.

-a

---

<div class="post-metadata">

**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 13, 2006, 4:40am UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/3 "2006-07-13T04:40:16Z")

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removed\_email\_address@domain.invalid wrote:

> ```
> DB = Prototype.new{
> host 'localhost'
> port 4242
> 
> def connect() 'do something' end
> 
> def inspect() [host, port].join ':' end
> }
> 
> ```

Why no go the extra step?

```
 DB = Prototype.new{
   host 'localhost'
   port 4242

   connect does{ 'do something' }

   inspect does{ [host, port].join ':' }
 }

```

T.

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<div class="post-metadata">

**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 13, 2006, 4:29pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/4 "2006-07-13T16:29:32Z")

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On Thu, 13 Jul 2006 removed\_email\_address@domain.invalid wrote:

> T.

easy enough, i’d simply make does() return a block extended with a  
marker:

def does &b  
class \<\< b  
def does() true end  
end  
b  
end

then, later

if b.respond\_to? ‘does’  
# defined a method  
else  
# attribute with proc value  
end

otherwise i could tell the difference between

foobar lambda{ ‘plain ol block’ }

foobar does{ ‘method body’ }

in any case, i’m unclear as to what

connect does{ ‘do something’ }

buys you over

def connect() ‘do something’ end

other than two chars. i admit it looks nice though… actually i guess  
the  
closure might make it nice since you could do

a = 42

connect does{ p a }

which you cannot with a normal method def. so - what’s **your**  
reasoning on  
this?

cheers.

-a

---

<div class="post-metadata">

**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 13, 2006, 9:30pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/5 "2006-07-13T21:30:29Z")

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removed\_email\_address@domain.invalid writes:

> Why no go the extra step?
> 
> ```
> DB = Prototype.new{
> host 'localhost'
> port 4242
> 
> connect does{ 'do something' }
> 
> inspect does{ [host, port].join ':' }
> }
> 
> ```

Why not even this:

```
    connect { 'do something' }

    inspect { [host, port].join ':' }
```

---

<div class="post-metadata">

**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 13, 2006, 10:06pm UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/6 "2006-07-13T22:06:35Z")

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On Fri, 14 Jul 2006, Christian N. wrote:

> Why not even this:
> 
> ```
> connect { 'do something' }
> 
> inspect { [host, port].join ':' }
> 
> ```

sold.

jib:~/eg/ruby/prototype/prototype-0.2.0 \> cat a.rb

require ‘prototype’

prototype{ connect { p ‘connect’ } }.connect

jib:~/eg/ruby/prototype/prototype-0.2.0 \> ruby -Ilib a.rb

“connect”

-a

---

<div class="post-metadata">

**Author:** ![BergerS\_Daniel](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bc8723/32.png) [@BergerS\_Daniel](https://www.ruby-forum.com/u/BergerS_Daniel)\
**Post date:** [July 14, 2006, 3:19am UTC](https://www.ruby-forum.com/t/re-prototype-design-pattern/98110/7 "2006-07-14T03:19:24Z")

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Christian N. wrote:

> Why not even this:
> 
> ```
> connect { 'do something' }
> 
> inspect { [host, port].join ':' }
> 
> ```

Sweet and fine! My, oh my, it’s looking like a paradigm.

T.