lib/sequitur/dynamic_grammar.rb in sequitur-0.0.14 vs lib/sequitur/dynamic_grammar.rb in sequitur-0.1.00

@@ -1,16 +1,17 @@
 require_relative 'production'
+require_relative 'grammar_visitor'
 
 module Sequitur # Module for classes implementing the Sequitur algorithm
 
 class DynamicGrammar
   # Link to the root - start - production.
   attr_reader(:root)
 
   # The set of production rules of the grammar
   attr_reader(:productions)
-  
+
   # nodoc Trace the execution of the algorithm.
   attr(:trace)
 
 
   # Constructor.
@@ -29,22 +30,22 @@
     rule_text = productions.map(&:to_string).join("\n")
     return rule_text
   end
 
 
-  # Add a production to the grammar.
+  # Add a given production to the grammar.
   def add_production(aProduction)
     # TODO: remove output
     puts "Adding #{aProduction.object_id}" if trace
     puts aProduction.to_string if trace
     check_rhs_of(aProduction) # TODO: configurable check
     productions << aProduction
   end
 
 
   # Remove a production from the grammar
-  def delete_production(anIndex)
+  def remove_production(anIndex)
     puts "Before production removal #{productions[anIndex].object_id}" if trace
     puts to_string if trace
     prod = productions.delete_at(anIndex)
     # TODO: remove output
     puts('Removed: ' + prod.to_string) if trace
@@ -57,10 +58,23 @@
   # Add the given token to the grammar.
   def add_token(aToken)
     append_symbol_to(root, aToken)
   end
 
+  # Part of the 'visitee' role.
+  # [aVisitor] a GrammarVisitor instance
+  def accept(aVisitor)
+    aVisitor.start_visit_grammar(self)
+    productions.each { |prod| prod.accept(aVisitor) }
+    aVisitor.end_visit_grammar(self)
+  end
+
+  # Factory method. Returns a visitor for this grammar.
+  def visitor()
+    return GrammarVisitor.new(self)
+  end
+
   protected
 
   def append_symbol_to(aProduction, aSymbol)
     aProduction.append_symbol(aSymbol)
   end
@@ -78,9 +92,20 @@
       msg << ' that is not part of the grammar.'
       fail StandardError, msg
     end
   end
 
+
+  # Visitor pattern.
+  # A visitee is expected to accept the visit from a visitor object
+  def accept(aVisitor)
+    aVisitor.start_visit_grammar(self)
+
+    # Let's proceed with the visit of productions
+    productions.each { |a_prod| a_prod.accept(aVisitor) }
+
+    aVisitor.end_visit_grammar(self)
+  end
 end # class
 
 end # module
 
 # End of file