Lua primitives: index_highlight_mode()
When the global_mode is set to index you will be presented with a list of messages.
You may navigate through these messages, and the currently selected message will be highlighted visually.
The index_highlight_mode() helper allows you to choose how that highlighting is applied. Valid options are:
NOTE: You can combine values, so this is valid:
index_highlight_mode( "bold reverse");
The default is "standout".
This function has been available since version 0.20.