COHERENCE.md §14 grades Tree as the last missing workbench primitive,
and §20 Priority 5 names it as what remains after the bottom panel. Its
argument is to build it once "before dired's directory view and the
workers tree harden their own conventions".
THIS FRAMING NARROWS THAT ARGUMENT DELIBERATELY. §14 lists six future
consumers, and designing a shared primitive against six hypothetical
ones is how you get a model that fits none. The scout found a better
basis: one consumer already ships a tree and fakes it, and a second is
already scoped and deliberately deferred.
THE HIERARCHY ALREADY EXISTS AND IS ALREADY DISCARDED. `Symbol::
push_hier` walks a genuine LSP DocumentSymbol tree — it recurses on
`children` — and flattens it, preserving `depth`, a `::`-joined parent
chain, and document order with parents before children. `lsp.lua` then
re-renders that depth as LEADING SPACES INSIDE THE ROW TEXT, under its
own comment "FLAT with a `depth` field --- indent, don't recurse". So
the outline has no collapse, no expand, no parent/child navigation, and
every input a tree needs is already computed. It is the anchor consumer
because it needs no new plumbing and its limitation is observable today
rather than hypothetical.
Dired is the second: it landed a flat listing for Emacs parity and
deferred `i` insert-subdirectory in its own §13 — the restraint §14
credits, and what keeps the door open.
The workers view is NOT a consumer yet: it is a Rust-generated text
buffer raw-switched into the active window, with no rows.
REFRESH RESTORES A LINE, NOT A NODE, and that is the crux rather than a
detail. `listview.refresh` saves `cursor_line()`, rebuilds rows wholesale
from a freshly produced array, and re-seats by walking `move_down`.
Today that is a mild wrong-restore. Collapse breaks it outright, because
expanding a node inserts rows ABOVE the cursor — and collapse state
itself must survive refresh, which requires recognising "the same node"
across two independently produced arrays. Neither `line_to_item` nor an
opaque `item` can do that. This is why the stable-identity question
decides whether selection and expansion survive a model update at all.
Four questions are left genuinely open: extend listview versus a
separate treeview (no leaning recorded — the scout found nothing that
decides it); who owns collapse state; what a stable node identity is;
and whether the row still carries pre-rendered text. On identity the
scout did establish constraints: listview cannot derive one because
`item` is opaque; the outline's parent chain plus name is nearly
sufficient but collides on overloads; dired's path would be genuinely
stable. So identity is almost certainly consumer-supplied, which makes
it part of the public contract rather than an internal detail.
NO INTERACTION ISLAND unless evidence forces one. Expand/collapse are
buffer-local bindings on a generated buffer, exactly as RET/n/p/g/q
already are. §6 grades islands "weak, and growing"; this must not add to
that count, and if some behaviour cannot be expressed that way it is a
finding to report rather than a licence.
§1.6 states plainly what this document is: unlike the last two lanes
there is no fallout to census and no baseline to diff, so it ARGUES a
model rather than measuring one — the shape that has historically needed
the most review rounds here.
Framing only. Acceptance is explicitly not final pending the open
questions.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Levi Neuwirth
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