I’m designing my own programming language for fun, and I’m thinking of making it fully Object-oriented (no statics, no globals, no class variables, no class methods), so I need to find a way to completely eliminate the needs of class methods, but, first, I need to make sure that I know all the problems that could only be solved by using class methods.

So, usually, class methods is used for creating helpers, and named constructors, yes? (Anything else?).

Currently, this is what I have to replace those with Object-oriented designs:

For example: the File helpers, I’m thinking of designing it like this:

class File
  def initialize(path)
    @path = path
  end

  def copy(destination)
    # Copy file from @path to destination
    # Then open destination path by creating new file instance
  end
end

I’m actually using C, but I wrote the example in Ruby so it will be easier to understand.

No class methods, and you could chain it like this:

File.new("directory/file").copy("new_path").copy("other_path")

If its too long, I could just drop the “new” method like what Python do:

File("directory/file").copy("new_path").copy("other_path")

Math helpers can be replaced with mixins:

module Math
  def pow(value)
    @value = @value ** value
  end
end

class Integer
  include Math

  def initialize(value)
    @value = value
  end
end

Call it like this:

Integer.new(100).pow(10).pow(10).pow(10)

In case you still need some helpers:

module Helpers
  # Some block of codes
end

class Object
  include Helpers
end

And now it’s accessible everywhere.

To add more helpers, just modify the Helpers module:

module Helpers
  # Add more helpers
end

We can create factory class instead of named constructor:

class Lexer
  def initialize(source)
    @source = source
  end
end

class LexerFactory
  def create_from_file(file)
    return Lexer.new(File.read(file))
  end

  def create_from_string(string)
    return Lexer.new(string)
  end
end

class Base
  def initialize(lexer_factory)
    @lexer_factory = lexer_factory
  end

  def lexer
    @lexer_factory
  end
end

lexer = Base.new(LexerFactory.new).lexer.create_from_file("directory/file")

So my questions is: What am I missing? What you can’t do without class methods, and class variables? What problems that could only be solved by using those?