From: James Edward Gray II <james@...>
Date: 2007-07-12T23:45:03+09:00
Subject: Re: Abstract methods in ruby ?

On Jul 12, 2007, at 9:17 AM, Robert Dober wrote:

> On 7/12/07, James Edward Gray II <james@grayproductions.net> wrote:
> <snip>
>> > If you are looking for warnings or errors for subclasses not
>> > implementing the abstract method you will be disappointed at  
>> Compile
>> > Time [which arguabley does not even exist in 1.8]
>>
>> class AbtractClass
>>    REQUIRED_METHODS = %w[one two three]
>>
>>    def self.inherited(subclass)
>>      REQUIRED_METHODS.each do |m|
>>        raise "An implementation of #{m} is required by # 
>> {self.class}" \
>>          unless subclass.instance_methods.include? m
>>      end
>>    end
>> end
>>
>> class Broken < AbtractClass
>>    def one; end
>>    def two; end
>> end
>> # ~> -:7:in `inherited': An implementation of one is required by
>> Class (RuntimeError)
>> # ~>    from -:5:in `each'
>> # ~>    from -:5:in `inherited'
>> # ~>    from -:12
>>
>> But don't do that.  ;)
> That does not work as you have intended, it is complaining about #one
> missing as a matter of fact:

You are right.  My mistake.

James Edward Gray II