# File lib/parslet/bytecode/vm.rb, line 144
    def store_cache(adr)
      if success?
        pos, result = pop(2)
        key = [pos, adr.address]
        @cache[key] = [true, result, source.pos-pos]
        push result
      else
        pos = pop
        key = [pos, adr.address]
        @cache[key] = [false, @error, source.pos-pos]
      end
    end