safer

safer.rubyforge.org

DESCRIPTION:

Safer is an umbrella library, with components designed to make it simple to verify and improve the safety of your ruby code. There are at present three modules under the safer umbrella:

Safer::IVar

generates specially-named accessor functions for class instance variables.

Safer::Protocol

is used to provide a ruby analogue to Objective-C Protocols (which are similar to Java interfaces, but do not require inheritance).

Safer::HashProtocol

verifies that a Hash keys follow a defined

format. Intended to help use of Hash objects as keyword parameters.

FEATURES/PROBLEMS:

• Name instance variables after the class in which they are defined. Generate accessor functions for these instance variables.

• Define a “Protocol” class, and derive a signature from it. Verify that another class (or an instance of that class) implements the protocol signature.

• Define a check if a Hash contains a desired combination of keys.

SYNOPSIS:

require 'safer/ivar'
require 'safer/protocol'
require 'safer/hashprotocol'

module MyModule
  class MyProtocolClass
    def self.class_method_foo(arg1, arg2)
    end
    def instance_method(arg3)
    end
  end
  PROTOCOL = Safer::Protocol.create_from_class(MyProtocolClass)
  class MyClass
    Safer::IVar.instance_variable(self, :var1, :var2)
    def initialize(var1, var2)
      PROTOCOL.instance_conforms?(var1)
      PROTOCOL.instance_conforms?(var2)
      self.mymodule_myclass__var1 = var1
      self.mymodule_myclass__var2 = var2
    end

    SHP = Safer::HashProtocol
    V1Keywords = SHP::HasKey.create(:name, :type)
    V2Keywords = SHP::HasKey.create(:first, :last, :type)
    V1Check = SHP::Only.new(SHP::Any.new(*V1Keywords))
    V2Check = SHP::Only.new(SHP::Any.new(*V2Keywords))
    ValidCheck = SHP::Any.new(V1Check, V2Check)
    def my_fn(h)
      if ! (ValidCheck === h)
        raise ArgumentError, "h should conform to #{ValidCheck.description}"
      end
      case h
      when V1Check
        v1_process(h[:name], h[:type])
      when V2Check
        v2_process(h[:first], h[:last], h[:type])
      end
    end
  end
end

REQUIREMENTS:

• None

INSTALL:

• sudo gem install safer

DEVELOPERS:

After checking out the source, run:

$ rake newb

This task will install any missing dependencies, run the tests/specs, and generate the RDoc.

LICENSE:

This software is placed into the public domain.