Use the more concise version of this pattern

Author: James Somers

Diff for: create_semantic_map_for_notes.rb

@@ -34,11 +34,7 @@ def count(t)
   index[id] = words
 
   words.each do |term|
-    if reverse_index[term]
-      reverse_index[term] << id
-    else
-      reverse_index[term] = [id]
-    end
+    (reverse_index[term] ||= []) << id
   end
 end
 
@@ -66,12 +62,8 @@ def tf_idf(term, doc, index, reverse_index)
   words.uniq.collect {|w| [tf_idf(w, doc, index, reverse_index), w]}.each do |pair|
     word = pair[1]
     weight = pair[0]
-    if semantics[word]
-      semantics[word] << [weight, doc]
-    else
-      semantics[word] = [[weight, doc]]
-    end
+    (semantics[word] ||= []) << [weight, doc]
   end
 end
 
-ObjectStash.store semantics, './semantics.stash'
+ObjectStash.store semantics, './semantics.stash'