Create common FA/State/Transition classes across NFA/DFA

lib/imbecile/regex/fa/state.rb

@@ -0,0 +1,53 @@
+module Imbecile
+  class Regex
+    class FA
+
+      class State
+
+        attr_accessor :accepts
+        attr_reader :transitions
+
+        def initialize
+          @transitions = []
+        end
+
+        def add_transition(code_point_range, destination)
+          @transitions << Transition.new(code_point_range, destination)
+        end
+
+        # Determine the set of states that can be reached by nil transitions.
+        # from this state.
+        #
+        # @return [Set<NFA::State>]
+        #   Set of states.
+        def nil_transition_states
+          states = Set[self]
+          analyze_state = lambda do |state|
+            state.nil_transitions.each do |transition|
+              unless states.include?(transition.destination)
+                states << transition.destination
+                analyze_state[transition.destination]
+              end
+            end
+          end
+          analyze_state[self]
+          states
+        end
+
+        def nil_transitions
+          @transitions.select do |transition|
+            transition.nil?
+          end
+        end
+
+        def cp_transitions
+          @transitions.reject do |transition|
+            transition.nil?
+          end
+        end
+
+      end
+
+    end
+  end
+end

lib/imbecile/regex/fa/state/transition.rb

@@ -0,0 +1,25 @@
+module Imbecile
+  class Regex
+    class FA
+      class State
+
+        class Transition
+
+          attr_reader :code_point_range
+          attr_reader :destination
+
+          def initialize(code_point_range, destination)
+            @code_point_range = code_point_range
+            @destination = destination
+          end
+
+          def nil?
+            @code_point_range.nil?
+          end
+
+        end
+
+      end
+    end
+  end
+end