Class: Rley::Notation::ASTVisitor

Inherits:
Object
  • Object
show all
Defined in:
lib/rley/notation/ast_visitor.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(aTop) ⇒ ASTVisitor

Build a visitor for the given top.

Parameters:

Raises:

  • (StandardError) 


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# File 'lib/rley/notation/ast_visitor.rb', line 14

def initialize(aTop)
  raise StandardError if aTop.nil?

  @top = aTop
  @subscribers = []
end

Instance Attribute Details

#subscribers ⇒ Object (readonly)

List of objects that subscribed to the visit event notification.



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# File 'lib/rley/notation/ast_visitor.rb', line 10

def subscribers
  @subscribers
end

#top ⇒ Object (readonly)

Link to the top node to visit



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# File 'lib/rley/notation/ast_visitor.rb', line 7

def top
  @top
end

Instance Method Details

#end_visit_ptree(aParseTree) ⇒ Object

Visit event. The visitor has completed the visit of the ptree.

Parameters:



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# File 'lib/rley/notation/ast_visitor.rb', line 47

def end_visit_ptree(aParseTree)
  broadcast(:after_ptree, aParseTree)
end

#start ⇒ Object

The signal to begin the visit of the top.



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# File 'lib/rley/notation/ast_visitor.rb', line 35

def start
  top.accept(self)
end

#start_visit_ptree(aParseTree) ⇒ Object

Visit event. The visitor is about to visit the ptree.

Parameters:



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# File 'lib/rley/notation/ast_visitor.rb', line 41

def start_visit_ptree(aParseTree)
  broadcast(:before_ptree, aParseTree)
end

#subscribe(aSubscriber) ⇒ Object

Add a subscriber for the visit event notifications.

Parameters:

  • aSubscriber (Object) 


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# File 'lib/rley/notation/ast_visitor.rb', line 23

def subscribe(aSubscriber)
  subscribers << aSubscriber
end

#unsubscribe(aSubscriber) ⇒ Object

Remove the given object from the subscription list. The object won't be notified of visit events.

Parameters:

  • aSubscriber (Object) 


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# File 'lib/rley/notation/ast_visitor.rb', line 30

def unsubscribe(aSubscriber)
  subscribers.delete_if { |entry| entry == aSubscriber }
end

#visit_grouping_node(aGroupingNode) ⇒ Object

Visit event. The visitor is about to visit a grouping node.

Parameters:



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# File 'lib/rley/notation/ast_visitor.rb', line 68

def visit_grouping_node(aGroupingNode)
  broadcast(:before_grouping_node, aGroupingNode, self)
  traverse_subnodes(aGroupingNode) if aGroupingNode.repetition == :exactly_one
  broadcast(:after_grouping_node, aGroupingNode, self)
end

#visit_sequence_node(aSequenceNode) ⇒ Object

Visit event. The visitor is about to visit a sequence node.

Parameters:



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# File 'lib/rley/notation/ast_visitor.rb', line 60

def visit_sequence_node(aSequenceNode)
  broadcast(:before_sequence_node, aSequenceNode, self)
  traverse_subnodes(aSequenceNode)
  broadcast(:after_sequence_node, aSequenceNode, self)
end

#visit_symbol_node(aSymbolNode) ⇒ Object

Visit event. The visitor is about to visit a symbol node.

Parameters:



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# File 'lib/rley/notation/ast_visitor.rb', line 53

def visit_symbol_node(aSymbolNode)
  broadcast(:before_symbol_node, aSymbolNode, self)
  broadcast(:after_symbol_node, aSymbolNode, self)
end