Add comment about Walrus-specific :origin key

Signed-off-by: Wincent Colaiuta <win@wincent.com>

diff --git a/lib/walrat/memoizing_cache.rb b/lib/walrat/memoizing_cache.rb
index 3f5f6ebb5195a982528cce51e4fc61cca771cc4c..7e371309c429990eaf7ed3ec09ad2dfd1930f63a 100755 (executable)
--- a/lib/walrat/memoizing_cache.rb
+++ b/lib/walrat/memoizing_cache.rb
@@ -74,6 +74,9 @@ module Walrat
 
       # construct a unique identifier
       identifier = [options[:parseable], options[:line_start], options[:column_start]]
+
+      # BUG: the :origin key here is specific to Walrus (doesn't appear anywhere else
+      # in Walrat codebase)
       identifier << options[:origin] if options.has_key? :origin
       identifier << options[:skipping_override] if options.has_key? :skipping_override