fragmentation

Content-addressed, arbitrary-depth, circular-reflexive trees. Reality for git.

gleam add fragmentation@1

What This Is

A Gleam library for building trees where every node knows its own address, carries a witness record of who observed it, and contains its children directly. Two node types: Shard (terminal) and Fragment (recursive). Four fields on every witness: author, committer, timestamp, message – the same four fields as a git commit.

Different witness, different hash. The observation is part of the content.

import fragmentation

let witness = fragmentation.witnessed(
  fragmentation.author("alex"),
  fragmentation.committer("reed"),
  fragmentation.timestamp("2026-03-01T00:00:00Z"),
  fragmentation.message("initial"),
)
let leaf = fragmentation.shard(
  fragmentation.ref(fragmentation.hash("leaf-data"), "self"),
  witness,
  "leaf-data",
)
let root = fragmentation.fragment(
  fragmentation.ref(fragmentation.hash("root"), "self"),
  witness,
  "root",
  [leaf],
)

// Content-addressed: same content = same hash
fragmentation.hash_fragment(root)

Modules

Module	Purpose
`fragmentation`	Core types, construction, hashing, queries
`fragmentation/store`	Content-addressed in-memory storage (Sha -> Fragment)
`fragmentation/walk`	Depth-first traversal, fold, find, depth
`fragmentation/diff`	Structural comparison between trees

Documentation

See docs/ for the full documentation, including:

What fragmentation is and why these types
Why the witness record changes the hash
How the modules compose
A guide for agents building on this library

Development

gleam test  # 62 tests

Licence

LICENSE.md contains the Apache-2.0 licence required by Hex. The actual governing terms are the Systemic Engineering License v1.0.