Refactor visitors

amanuensis/parser/analyze.py

@@ -5,7 +5,39 @@ for verification against constraints.
 
 import re
 
-class FeatureCounter():
+class RenderableVisitor():
+	"""Default implementation of the visitor pattern"""
+	def TextSpan(self, span):
+		return self
+	def LineBreak(self, span):
+		return self
+	def ParsedArticle(self, span):
+		span.recurse(self)
+		return self
+	def BodyParagraph(self, span):
+		span.recurse(self)
+		return self
+	def SignatureParagraph(self, span):
+		span.recurse(self)
+		return self
+	def BoldSpan(self, span):
+		span.recurse(self)
+		return self
+	def ItalicSpan(self, span):
+		span.recurse(self)
+		return self
+	def CitationSpan(self, span):
+		span.recurse(self)
+		return self
+
+class GetCitations(RenderableVisitor):
+	def __init__(self):
+		self.citations = []
+	def CitationSpan(self, span):
+		self.citations.append(self.cite_target)
+		return self
+
+class FeatureCounter(RenderableVisitor):
 	def __init__(self):
 		self.word_count = 0
 		self.citation_count = 0
@@ -15,30 +47,11 @@ class FeatureCounter():
 		self.word_count += len(re.split('\s+', span.innertext.strip()))
 		return self
 
-	def LineBreak(self, span):
-		return self
-
-	def ParsedArticle(self, span):
-		span.recurse(self)
-		return self
-
-	def BodyParagraph(self, span):
-		span.recurse(self)
-		return self
-
 	def SignatureParagraph(self, span):
 		self.has_signature = True
 		span.recurse(self)
 		return self
 
-	def BoldSpan(self, span):
-		span.recurse(self)
-		return self
-
-	def ItalicSpan(self, span):
-		span.recurse(self)
-		return self
-
 	def CitationSpan(self, span):
 		self.citation_count += 1
 		span.recurse(self)