import sys
import debugger_pretty_printers_common as rustpp
+# We want a version of `range` which doesn't allocate an intermediate list,
+# specifically it should use a lazy iterator. In Python 2 this was `xrange`, but
+# if we're running with Python 3 then we need to use `range` instead.
if sys.version_info.major >= 3:
xrange = range