Records mode showed long format: a row per cell, a _Measure column naming
which measure it was, and a synthetic "Value" column holding the number.
Entering data meant sitting on "Value", and editing the measure column
renamed a coordinate rather than a value.
Wide format instead: a row is one coordinate tuple — the cells sharing every
coordinate but _Measure — and each raw measure gets its own editable column.
Two measures on one coordinate are now ONE row.
The case matrix came from a Prolog model rather than a read-through, which
surfaced the load-bearing consequence: a row now groups several cells, so
editing a category column must move all of them. The long-format code moved
only the cell under the cursor, which here would leave half a row's measures
under the old coordinate and half under the new. Both the plain-records and
staged-drill paths implement it.
_Dim in the synthetic key now carries the column index rather than a label,
because a category and a measure item may share a name and a label could not
say which column an edit landed on. GridLayout::record_col resolves it to a
RecordCol, and drill pending edits are keyed by (row, RecordCol) — which also
frees ApplyAndClearDrill from depending on the layout still being the drill
layout.
A blank model has no measures, so wide format alone would leave nowhere to
type a number and break the onboarding path. A trailing "+" column creates a
measure by name; being a schema change, it applies immediately rather than
staging inside a drill.
Formula targets are not columns — they are computed, so there is nothing to
type into them.
prune_empty's records branch went with it: the function early-returns in
records mode, so that tail could never run. Filed as improvise-2yk in case
the early return is itself the bug.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V69PGQfMJuGRmtSWpfVAqn
Edward Langley
22964f99be