tuple.rb in veritas-0.0.5

- old
+ new

@@ -11,10 +11,17 @@
     # @return [Header]
     #
     # @api private
     attr_reader :header
 
+    # The tuple data
+    #
+    # @return [Hash]
+    #
+    # @api private
+    attr_reader :data
+
     # Initialize a Tuple
     #
     # @param [Header] header
     #   the tuple header
     # @param [#to_ary] data
@@ -37,11 +44,11 @@
     #
     # @return [Object]
     #
     # @api public
     def [](attribute)
-      @data[header[attribute]]
+      data.fetch(header[attribute])
     end
 
     # Return a tuple with only the specified attributes
     #
     # @example
@@ -52,11 +59,11 @@
     #
     # @return [Tuple]
     #
     # @api public
     def project(header)
-      self.class.new(header, @data.values_at(*header))
+      self.class.new(header, data.values_at(*header))
     end
 
     # Append values to the tuple and return a new tuple
     #
     # @example
@@ -92,20 +99,31 @@
         header,
         extensions.map { |extension| Function.extract_value(extension, self) }
       )
     end
 
+    # Return the predicate matching the tuple
+    #
+    # @return [Function]
+    #
+    # @api private
+    def predicate
+      header.reduce(Function::Proposition::Tautology.instance) do |predicate, attribute|
+        predicate.and(attribute.eq(self[attribute]))
+      end
+    end
+
     # Convert the Tuple into an Array
     #
     # @example
     #   array = tuple.to_ary
     #
     # @return [Array]
     #
     # @api public
     def to_ary
-      @data.values_at(*header).freeze
+      data.values_at(*header).freeze
     end
 
     # Compare the tuple with other tuple for equivalency
     #
     # @example
@@ -116,14 +134,12 @@
     #
     # @return [Boolean]
     #
     # @api public
     def ==(other)
-      header = self.header
-      other  = self.class.coerce(header, other)
-      header == other.header &&
-      to_ary == other.project(header).to_ary
+      other = self.class.coerce(header, other)
+      data == other.data
     end
 
     # Compare the tuple with other tuple for equality
     #
     # @example
@@ -134,14 +150,12 @@
     #
     # @return [Boolean]
     #
     # @api public
     def eql?(other)
-      header = self.header
       instance_of?(other.class) &&
-      header.eql?(other.header) &&
-      to_ary.eql?(other.project(header).to_ary)
+      data.eql?(other.data)
     end
 
     # Return the hash of the tuple
     #
     # @example
@@ -149,23 +163,23 @@
     #
     # @return [Fixnum]
     #
     # @api public
     def hash
-      self.class.hash ^ header.hash ^ @data.hash
+      self.class.hash ^ data.hash
     end
 
     # Return a string representing the tuple data
     #
     # @example
-    #   tuple.inspect  # => "[1, 2, 3]"
+    #   tuple.inspect  # => "{<Attribute::Integer name: id>=>1}"
     #
     # @return [String]
     #
     # @api public
     def inspect
-      to_ary.inspect
+      data.inspect
     end
 
     # Coerce an Array-like object into a Tuple
     #
     # @param [Header] header
@@ -178,9 +192,9 @@
     # @api private
     def self.coerce(header, object)
       object.kind_of?(Tuple) ? object : new(header, object)
     end
 
-    memoize :hash, :to_ary
+    memoize :hash, :predicate, :to_ary
 
   end # class Tuple
 end # module Veritas