cache

Adding cache is necessary to avoid redundant processing of the same values through IntlMessageFormat, which significantly improves performance in scenarios with long lists.

Start by locating the IntlMessageFormat processing path and determine where repeated values are handled. Define how cached results should be keyed and invalidated, then verify that repeated formatting avoids redundant processing and that existing behavior remains unchanged; the issue names no files or tests.

Written by the indexing model from the issue text.