`improvise cmd` and `improvise script` resolved every command through
`CmdRegistry::parse` — the pure arm, which builds `CursorState::default()`: row
0, col 0, and a grid of zero rows and zero columns. The interactive arm, which
builds `CursorState::from_ctx(ctx)`, was never reached from a script. So every
`Move` and `enter-advance` snapshotted a zeroed cursor at PARSE time, clamped to
(0, 0) and emitted `SetSelected(0, 0)` — worse than a no-op, since it RESETS the
cursor. Nothing could position it, so every cursor-reading command was pinned to
the origin.
Reproduced at a9cad15 on a document with Region on row carrying North, South,
East: `move-selection 2 0 . hide-selected-row-item` and a bare
`hide-selected-row-item` both wrote `hidden: Region/North`. After the fix the
first writes `hidden: Region/East`.
The repair is `parse::segments` + `parse::parse_segment_interactive`, with the
headless loop re-parsing per segment, because command n must see command n-1's
cursor. Line atomicity is preserved by keeping the existing whole-line
`parse_line` as a syntax gate, so a line that parsed before still parses and the
only behavioural change is which cursor the commands see.
Two things the ticket did not predict. The TUI's `:` line had the identical
defect — `ExecuteCommand` also used the pure arm — and is fixed the same way.
And doing that surfaced a second instance of the same shape one level down:
`register_pure` built an interactive arm that refused EMPTY args while its own
pure arm accepted them, so `w` with no path parsed one way and refused the
other, breaking `improvise cmd 'w'` and `:w` the moment either re-parsed
interactively. Both arms are now `parse`.
Evidence: context/test-evidence/cli.md; reasoning: context/code/cli.md section 7.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FC2jVn8Au7E9JPkw6bwXXH
Edward Langley
64bcb821da