Experimental version of Sf, pre-release

sf.rb

class Sf
  attr_reader :operations

  OPERATORS = %i(+ - * / % < > <= >= == && & || |)

  INSTANCE_OP = -> name {
    -> method_name, *args, **kwargs, &fn {
      @operations.push(method_name: name, args: args, kwargs: kwargs, fn: fn)

      self
    }
  }

  CLASS_OP = -> name {
    -> method_name, *args, **kwargs, &fn {
      self.new([method_name: name, args: args, kwargs: kwargs, fn: fn])
    }
  }

  OPERATORS.each do |op|
    self.define_method(op, &INSTANCE_OP[op])
    singleton_class.define_method(op, &CLASS_OP[op])
  end

  def method_missing(method_name, *args, **kwargs, &fn)
    @operations.push(method_name: method_name, args: args, kwargs: kwargs, fn: fn)

    self
  end

  def self.method_missing(method_name, *args, **kwargs, &fn)
    CLASS_OP[method_name].call(*args, **kwargs, &fn)
  end

  def initialize(operations)
    @operations = operations
  end

  def to_proc
    -> object { call(object) }
  end

  def call(object)
    @operations.reduce(object) { |obj, method_name:, args:, kwargs:, fn:|
      if kwargs.empty? 
        obj.public_send(method_name, *args, &fn)
      else
        obj.public_send(method_name, *args, **kwargs, &fn)
      end
    }
  end

  def ===(object)
    call(object)
  end
end