lib/minimus.rb in minimus-0.1.0 vs lib/minimus.rb in minimus-0.1.1

@@ -2,17 +2,18 @@
 
 class Minimus
 
   TransitionError = Class.new(StandardError)
 
-  attr_reader :states, :initial_state
+  attr_reader :states, :initial_state, :possibilities
   attr_accessor :current_state
 
   def initialize(*states)
     @states = states
     @initial_state = states.first
     @current_state = initial_state
+    @possibilities = {}
   end
 
   def move(new_state)
     return false unless move_possible?(new_state)
     self.current_state = new_state
@@ -20,19 +21,30 @@
     yield if block_given?
   end
 
   def move!(new_state)
     unless move_possible?(new_state)
-      raise TransitionError, %Q{unallowed transition from
-         #{current_state} to #{new_state}}
+      raise TransitionError, %(unallowed transition from
+         #{current_state} to #{new_state})
     end
     self.current_state = new_state
 
     yield if block_given?
   end
 
+  def can(state, possible:)
+    possible_array = Array(possible)
+    return unless possible_array.all? { |value| states.include?(value) }
+
+    possibilities[state] = possible_array
+  end
+
   private
 
   def move_possible?(new_state)
-    states[states.index(current_state) + 1] == new_state
+    if state_possibilities = possibilities[current_state]
+      state_possibilities.include?(new_state)
+    else
+      states[states.index(current_state) + 1] == new_state
+    end
   end
 end