rupaka

rupaka (रूपक) means a form, a play that the audience sees, and the figure of speech that shows one thing through another. A rupaka demo is one interactive figure that teaches one idea. The learner changes the inputs and sees the result change.

A demo never shows the answer first. Each demo follows one loop:

1. Predict. The demo shows the inputs and asks one question. The result is hidden.
2. Reveal. The learner locks in with ⌘↩. The demo shows the result and says if the prediction was right.
3. Manipulate. Now the controls are live. The result changes when the inputs change.
4. Explain. The caption ends with a new question that the learner answers with the controls.

The validator enforces step 1: a block that shows a value which the answer depends on must wait for the gate.

What a demo is

A demo is a JSON spec, not code. It has a small state, derived values from named functions (fns), and a list of blocks. A model can write a spec safely, because a spec cannot run code.

part	what it is
block	a reusable UI part in rupaka/blocks/<name>/: its JS, its CSS, a block.json manifest and an example
fn	a pure function that computes a derived value: rules, rrf, softmax, lookup, expr, ids, pick, sort, fmt
gate	the block that asks for the prediction and hides the result until the lock in
spec	the JSON object: state, derive, blocks and tables

The blocks are gate, readout, caption, row, stack, slider, toggle, choice, wheel, ranklist, bars, axis, point, plot and grid.

Install

pip install rupaka

The headless check needs playwright: pip install "rupaka[check]". It uses the Chromium that playwright install chromium gives, or the browser in $FASTCDP_CHROME. It never runs your everyday Chrome.

How to use

Build a spec with the builders, or write the JSON.

from rupaka.spec import *

d = demo('sum', 'A sum', ask='Predict the sum before you see it.', state=dict(a=2, b=3), derive=[expr('a + b', 'sum')],
         blocks=[gate('s', 'What is {a} + {b}?', [4, 5, 6], 'sum', why='Say why, in one line.'),
                 readout('{a} + {b} = {sum}', after='s')])

validate returns the errors. An empty list means the spec is good.

assert validate(d) == []

A readout that shows the sum before the gate breaks the think rule:

bad = {**d, 'blocks': [d['blocks'][0], readout('{a} + {b} = {sum}')]}
validate(bad)

Then put the demo where the learner is:

where	how
a notebook (leela, Jupyter)	show(spec): an HTML output in a sandboxed frame, and the application/vnd.rupaka+json mime
Markdown	md(spec) writes a ```rupaka fence; md(spec, frame=True) writes a frame that leela draws today
a FastHTML page	Demo(spec) and Assets('/rupaka'); serve bundle('js') and bundle('css') at that prefix
a file	save(spec, 'demo.html') writes one page that works from file:// with no network

check(spec) draws the demo in headless Chrome and plays it. author(concept, ask) asks a model for a demo, and checks and repairs it.

The gallery

rupaka/demos/ holds hand-made demos: vowel sandhi, reciprocal rank fusion, softmax and temperature, nakṣatra and pāda, and a parabola.

Develop

The notebooks in nbs/ are the source of the Python. The JS and CSS are hand-written files under rupaka/static/, rupaka/blocks/ and rupaka/fns/.

uv sync
uv run nbdev-prepare
uv run pytest