class Treetop::Compiler::ParsingRule

def generate_cache_lookup(builder)
  builder.if_ "node_cache[:#{name}].has_key?(index)" do
    builder.assign 'cached', "node_cache[:#{name}][index]"
    builder.if_ "cached" do
      builder << 'cached = SyntaxNode.new(input, index...(index + 1)) if cached == true'
      builder << '@index = cached.interval.end'
    end
    builder << 'return cached'
  end
end