Module: Contracts

Defined in:
lib/contracts/builtin_contracts.rb,
lib/contracts.rb,
lib/contracts/errors.rb,
lib/contracts/modules.rb,
lib/contracts/support.rb,
lib/contracts/version.rb,
lib/contracts/decorators.rb,
lib/contracts/eigenclass.rb,
lib/contracts/formatters.rb,
lib/contracts/invariants.rb,
lib/contracts/method_reference.rb

Overview

rdoc This module contains all the builtin contracts. If you want to use them, first:

import Contracts

And then use these or write your own!

A simple example:

Contract Num, Num => Num
def add(a, b)
  a + b
end

The contract is Contract Num, Num, Num. That says that the add function takes two numbers and returns a number.

Defined Under Namespace

Modules: Eigenclass, Formatters, Invariants, MethodDecorators, Modules, Support Classes: And, Any, Args, Bool, CallableClass, CollectionOf, ContractsNotIncluded, Decorator, Eq, Exactly, Func, HashOf, Maybe, MethodReference, Nat, Neg, None, Not, Num, Or, Pos, RespondTo, Send, SingletonMethodReference, Xor

Constant Summary collapse

VERSION =
"0.9"
ArrayOf =

Takes a contract. The related argument must be an array. Checks the contract against every element of the array. If it passes for all elements, the contract passes. Example: ArrayOf[Num]

CollectionOf::Factory.new(Array)
SetOf =

Takes a contract. The related argument must be a set. Checks the contract against every element of the set. If it passes for all elements, the contract passes. Example: SetOf[Num]

CollectionOf::Factory.new(Set)

Class Method Summary collapse

Class Method Details

.common(base) ⇒ Object


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# File 'lib/contracts.rb', line 20

def self.common(base)
  Eigenclass.lift(base)

  return if base.respond_to?(:Contract)

  base.extend(MethodDecorators)

  base.instance_eval do
    def functype(funcname)
      contracts = decorated_methods[:class_methods][funcname]
      if contracts.nil?
        "No contract for #{self}.#{funcname}"
      else
        "#{funcname} :: #{contracts[0]}"
      end
    end
  end

  base.class_eval do
    unless base.instance_of?(Module)
      def Contract(*args)
        return if ENV["NO_CONTRACTS"]
        if self.class == Module
          puts %{
Warning: You have added a Contract on a module function
without including Contracts::Modules. Your Contract will
just be ignored. Please include Contracts::Modules into
your module.}
        end
        self.class.Contract(*args)
      end
    end

    def functype(funcname)
      contracts = self.class.decorated_methods[:instance_methods][funcname]
      if contracts.nil?
        "No contract for #{self.class}.#{funcname}"
      else
        "#{funcname} :: #{contracts[0]}"
      end
    end
  end
end

.extended(base) ⇒ Object


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# File 'lib/contracts.rb', line 16

def self.extended(base)
  common(base)
end

.included(base) ⇒ Object


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# File 'lib/contracts.rb', line 12

def self.included(base)
  common(base)
end