flat_level_labels: Build colon-joined tuple labels from a list of level vectors
Description
Internal helper used by flatten() to produce dim-name labels for
the T x T form. Iterates the first grouping fastest, matching the
column-major reshape order.
Usage
flat_level_labels(levels)
Value
a character vector of length T = prod(lengths)
Arguments
- levels
a list of character vectors, one per grouping