dipa-cumulo

A Rust reimplementation of the calcium-workflow architecture: server ↔ client state sync via diff/patch over WebSocket, using dipa for delta encoding and respo.rs for WASM UI rendering.

Architecture

shared/     — shared data types (ClientStore, Op, ServerMsg …)
             derive DiffPatch + Serde on all state structs

server/     — Tokio + Axum WebSocket server
             • maintains AppDb (users + sessions) in memory
             • updater(db, op) → new_db   (pure function, no side effects)
             • twig_container(db, session) → ClientStore   (projection per session)
             • diffs old vs new ClientStore with dipa, sends patch bytes

client/     — wasm-pack WASM frontend (respo.rs)
             • receives Snapshot on connect, applies Patch on each change
             • dipa::Patchable::apply_patch() updates local ClientStore in-place
             • respo.rs renders virtual DOM from the store

Quick Start

Prerequisites

cargo install wasm-pack

Build client WASM

cd client
wasm-pack build --target web --out-dir dist/pkg

Run server

cd server
cargo run --release

Then open http://localhost:5021 in your browser.

Key Design Decisions

Concern	Calcit solution	Rust solution
Diff/patch	recollect (custom trie diff)	dipa (#[derive(DiffPatch)])
Transport	ws-edn (EDN over WS)	bincode (binary) over WebSocket
UI	Respo (ClojureScript)	respo.rs (WASM)
Server	Calcit server + Node WSS	Axum + Tokio
Pure updater	defn updater (db op …) → db	fn updater(db: AppDb, op: Op, …) → AppDb