: Build Update Map for Combined Target Categories

: Constructs an update map from settings$target_updates for use in labeling functions. This enables direct lookup such as update_map$target$combined_key$label, supporting combined or updated categories (e.g., "bike_walk" in p_commutemode). The returned list is structured so that, for each target with an update, combined categories are accessible as update_map[[target]][[combined_key]]$label.

Usage

build_update_map(settings)

Arguments

settings

A list containing a target_updates element, which must itself be a list of target update specifications. Each update can contain levels, label_levels, and/or groups entries, which are flattened if nested.

Value

A named list suitable for use in label_targets, where each combined category can be accessed via update_map$target$combined_key$label.