lib/rubype.rb in rubype-0.0.1 vs lib/rubype.rb in rubype-0.1.0

@@ -1,6 +1,49 @@
-require "rubype/version"
-require "rubype/rubype"
+require 'rubype/type_pair'
 
+# Builtin Contracts
+class  Any;     end
+module Boolean; end
+TrueClass.send(:include, Boolean)
+FalseClass.send(:include, Boolean)
+
+class Module
+  private
+  def __rubype__
+    prepend (@__rubype__ = Module.new) unless @__rubype__
+    @__rubype__
+  end
+
+  def type(*arguments)
+    *arg_types, type_pair, meth = arguments
+
+    __rubype__.send(:define_method, meth) do |*args, &block|
+      ::Rubype.assert_arg_type(meth, args, arg_types << type_pair.last_arg_type)
+      rtn = super(*args, &block)
+      ::Rubype.assert_trn_type(meth, rtn, type_pair.rtn_type)
+      rtn
+    end
+    self
+  end
+end
+
 module Rubype
-  # Your code goes here...
+  class << self
+    def assert_arg_type(meth, args, klasses)
+      args.each_with_index do |arg, i|
+        if wrong_type?(arg, klasses[i])
+          raise ArgumentError, "Wrong type of argument, type of #{arg.inspect} should be #{klasses[i]}"
+        end
+      end
+    end
+
+    def assert_trn_type(meth, rtn, klass)
+      if wrong_type?(rtn, klass)
+        raise TypeError, "Expected #{meth} to return #{klass} but got #{rtn.inspect} instead"
+      end
+    end
+
+    def wrong_type?(obj, klass)
+      !(obj.is_a?(klass) || klass == Any)
+    end
+  end
 end