finding the proper grammar for a given scope in a Redcar tab

scope_finder.rb

module Redcar
  class Comment
    java_import 'com.redcareditor.mate.Grammar'

    # Find a map of comment symbols for a grammar, using the a tab's cursor scope
    def self.find_by_scope tab

      # doc.cursor_scope is returned as space-delimited string of applicable
      # scopes, from most general, to most specific. For example,
      # in an erb file, the top scope would be something like 'text.html.ruby',
      # and inside a ruby block would be 'source.ruby.embedded.html'.
      scopes = tab.edit_view.document.cursor_scope.split(" ").reverse

      # search for the most specific scope possible, then default to a more
      # general one if none available
      scope = scopes.detect {|s| Grammar.find_by_scope_name(s)}

      if scope and grammar = Grammar.find_by_scope_name(scope)
        name = grammar.name
    	comment_map[name]
      end
    end
  end
end

# Issue:
#   Grammar doesn't seem to match a grammar to some of the embedded scopes.
# For instance, 'source.ruby.embedded.html' resolves to "HTML (Rails)"
# instead of "Ruby".
# Possible solution:
# Truncate scopes to the first two terms when no match is found
# ('source.ruby.embedded.html' -> 'source.ruby') ?