Is it possible to replicate the Override Annotation from Java in Ruby?

Question

I know that in Java, the Override annotation checks if the superclass has the method:

class Animal {
  public void speak () {
    System.out.println("Hello!");
  }
}
class Dog extends Animal {
  @override
  public void eat () { //this kind of stuff
    System.out.println("omnomnom");
  }
}

is there a way to do this in Ruby (as a function or something)?

Answer 1

this works, but it's a little verbose:

class OverrideError < StandardError
    def initialize a
        super("the superclass of `#{a[0]}`(`#{a[0].superclass}`) does not contain the method that has been attempeted to Override: `#{a[1]}`")
    end
end

#this function help the _override_ function ignore string literals
def delQ str
    str = str.gsub(/(".*"|'.*'|\%[qQ]?\{.*\})/, "")
    while /\= ?\<\<\-?[\w\_\?\!]+ /.match?(str)
        x = /\= ?\<\<\-?[\w\_\?\!]+ /.match(str)[0]
        stopname = x.sub(/\= ?\<\<\-?/, "")
        locat = str =~ /\= ?\<\<\-?[\w\_\?\!]+ .*/
        part = str.slice(locat)
        stop = part =~ %r{stopname}
        part1 = part.sub(%r{x + ".*" + stopname}, "")
        str = str.sub(part, part1)
    end
    return str
end

def _override_
    file = File.read("./" + caller[0][/[^:]+/]).split("\n")
    loc = (caller[0].to_s.scan(/\d+/).first).to_i
    line = file[loc]
    method = /def (self(\.|::))?[\w\_\?\!]+/.match(line)[0]
    method = method.gsub(/(def|self|\.|::|\s)/, "")
    clname = ""
    file = file.join("\n")
    file = delQ(file)
    file = file.split("\n")
    while loc >= 0
        substr = file[loc].gsub(/(\t|\n)/, "")
        if substr.start_with?("class ")
            clname = file[loc].gsub(/\t/, "").sub("class ", "")
            clname = /[\w_\?\!]+/.match(clname)[0]
            break
        end
        loc -= 1
    end
    clname = Kernel.const_get(clname)
    hmm = clname.superclass.method_defined?(method.to_sym)
    unless hmm
        raise OverrideError, [clname, method]
    end
end

A demonstration on how this will be used:

class Animal
    def initialize name
        @name = name
    end
    def speak
        puts "Hello!"
    end
end
class Dog < Animal
    def initialize name
        super name
    end
    _override_
    def speak
        # no error
        puts "woof!"
    end
    _override_ 
    def eat


#Traceback (most recent call last):
#   2: from main.rb:11:in `<main>'
#   1: from main.rb:19:in `<class:Dog>'
#/home/runner/Annotations/override.rb:41:in `_override_': the superclass #of `Dog`(`Animal`) does not contain the method that has been attempted #to Override: `eat` (OverrideError)


        puts "omnomnom"
    end
end