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Browse without dumping

You want to see the current root as typed values, expand a collection, and not download the whole tree. Dacite’s move: walk with value-type, count, nth, paged seq; never dac->clj. HTTP GET /node returns a packed neighborhood; the UI then walks values locally.

This is the sixth claim-proving app in the roadmap.

You will:

  1. Open /app/explorer/ against clojure -M:service.
  2. See every public Dacite type as type + value (not a JSON/EDN dump).
  3. Expand vectors, maps, and sets; page long collections 32 at a time.
  4. Measure that the first page of a 128-element vector costs less than seq of the whole vector.

Prerequisites

  • JDK 17+ and the Clojure CLI
  • A clone of this repo (see Install)

The shape

The explorer does not invent a domain. It displays whatever is at the server root. If the root is empty, it CAS-seeds a type gallery — a map that includes every public type, plus "page-me" (128 small maps) so paging is forced. An existing root (notes, event log, sync, todo) is left alone.

Domain code lives in dacite.examples.explorer and uses only dacite.value: value-type, count, nth, paged seq, lazy realize prefixes for strings/blobs. It never calls dac->clj.

The browser store is the same as the todo demo: write-back cache plus default pack-filled GET /node. One request returns data — realized literals for a neighborhood under the asked hash, inside the ~1k soft budget. apply-chunk! installs those as ordinary nodes in the tab’s mem cache. The explorer then walks values locally (dacite.value); a tree click is not a GET.

A 5-item todo list fits in a single literal, so load + expand of the first item is one node GET after GET /root. A title longer than 1k still takes several GETs, but each GET BFS-fills ~1k of neighborhood (last item may overshoot toward 2k). A refresh starts a new heap, so that cache is empty again.

String/blob rows still realize a short prefix of char/byte nodes; after a string literal those nodes are already local.

Strings and blobs are leaves: a truncated preview and the total count. A later “read more” can lengthen that prefix; this first pass does not.

Run

cd impl/clojure
clojure -M:cljs-explorer          # once / after cljs changes
clojure -M:service --port 8080 --store mem
# open http://127.0.0.1:8080/app/explorer/   (trailing slash)

Todo stays at http://127.0.0.1:8080/app/.

Reload re-fetches GET /root. It does not watch GET /events.

What to look at

  • Each row is a type badge then a summary (i64 -64, vector 3, string "prefix…" (n chars), blob n bytes 0x…).
  • Maps show typed keys as well as values (the gallery includes a vector key).
  • "page-me" is 128 entries; the first expand shows 32, then show next 32.
  • The bw line is store-protocol bodies only (GET /node, GET /root, CAS) — the same meter as the todo demo.

Existing data

Point the service at a store you already seeded:

cd impl/clojure
clojure -M:log -- --reset show          # 2000 events in target/dacite-log
clojure -M:service --port 8080 --store file:target/dacite-log
# open /app/explorer/ — the ledger, not the gallery

The explorer must not overwrite that root.

Measure

cd impl/clojure
clojure -M:dev:test -n dacite.examples.explorer-test

remote-expand-page-cheaper-than-full-seq seeds the gallery over HTTP, then compares a cold client’s first child-page of "page-me" with seq of all 128. Page bytes and requests stay strictly below the full walk.