quai

Interactive Quarb — a session REPL where every line becomes a reusable query.

cargo install quai
quai data.json

quai opens a session over one or more sources and holds it. Each line you run is labelled &1, &2, … — and every label is a reusable macro: not the printed value, but the query that produced it, ready to continue through the pipe. It is the notebook loop, cell by cell, except a cell is a path into your data.

&1  /teams/*/members/*
    /teams/0/members/0  ⋮  (every member, across all teams, one path)
&2  &1 | [/langs/*:: = 'Go'] | /name::
    ada
    eu
&3  &1 @| count
    6

• &N re-runs line N; continue with a pipe (&N | /key::, &N | [pred], &N @| count).
• &N! re-runs line N live (re-reads the source); &N# replays it frozen, as it was when it ran — over a moving source they diverge, and the difference is the drift.
• def &x: … ; adds a named fragment; :history, :reset, :help, :quit are the commands.
• --daemon backs the session with a resident arbor (materialize once, shared across runs); it composes with --cache.

quai reaches every source the engine mounts — JSON, YAML, TOML, CSV, XML, HTML, Markdown, SQLite, kaiv, the filesystem, git, archives, XLSX, and source code — and several at once mount under one root for cross-source <=> joins.

Try it in the browser at demo.quarb.org/quai (no install), and read the graph cookbook for the recipes. pip install quai gives the same REPL in Python.

License

Licensed under either of Apache License, Version 2.0 or the MIT license at your option.