@jarenjs/calc

A native, headless multi-mode calculator for the jarenjs stack: standard / scientific / programmer / financial / converter, with x·y and x·y·z plotting rendered as pure-vnode SVG through @jarenjs/view. The calculator is an @jarenjs/app document (state is JSON, keys are data bindings, transitions are copy-on-write RFC-6902 patches), and it is built on @jarenjs/core — it holds no formulas or unit factors of its own.

Zero runtime dependencies beyond @jarenjs/*. No eval, no new Function (CSP-safe). SSR-able and deterministic.

Two layers

• Engine (@jarenjs/calc) — pure functions over data. A two-stage expression compiler parseExpression(text) → ExprAST → compileExpr → (scope) => value, its canonical printer toExpression (a round-trip fixed point), and plot2d/plot3d/calcToVnode (pure-vnode SVG). Imports only @jarenjs/core + @jarenjs/view.
• Component (@jarenjs/calc/component) — the @jarenjs/app glue: createCalcComponent() → { initialState, actions, mode, rules, effects, subs, viewModel, createApp }, the keypad/panel JSLT view, the financial @jarenjs/forms panel, and the live crypto/fiat rates layer.

import { evaluate, parseExpression, toExpression, plot2d, toSvgString } from '@jarenjs/calc';

evaluate('sin(pi/2) + 2^10').value;          // 1025
toExpression(parseExpression('a-(b-c)'));    // "a - (b - c)"
toSvgString(plot2d('sin(x)', { domain: [-6.28, 6.28] })); // standalone SVG

import { createCalcComponent } from '@jarenjs/calc/component';
const calc = createCalcComponent({ provider: 'coingecko' });
const app = calc.createApp({ node: document.getElementById('calc') });

createCalcComponent({ codes, fallbackRates }) uses those currency choices and fallback rates for its exposed configuration and both initialization paths. Programmer Equals records the selected base on the tape; grouping spaces stay out of the committed expression so it can be used in the next calculation.

The numeric kernel lives in @jarenjs/core

Reusable primitives were pushed down into core, so any package can use them: @jarenjs/core/math (transcendentals, word.js BigInt word math, solve.js root finders, mat4/project.js 3D kernel, format.js), @jarenjs/core/finance (TVM, cash-flow, amortization, interest, depreciation, bond, indicators, returns) and @jarenjs/core/convert (fixed-factor dimensional conversion + the pure convertCurrency rate-table primitive). The calculator's financial mode calls core/finance; its converter calls core/convert. Core is pure and never fetches.

Changing the converter dimension updates its unit selections in the same transition. Existing choices survive when the new dimension offers them; otherwise it selects the first two available units (the same unit for both sides when only one exists). Currency choices come from the current rate table. A dimension with no available units leaves the conversion unchanged.

Live currency (the maturity example)

The converter's currency dimension takes live crypto+fiat rates from free public tickers (CoinGecko default, Binance alternative) through an @jarenjs/app effect + a when-gated polling subscription. The pure conversion is @jarenjs/core/convert's convertCurrency; only the fetch is component-side. A static fallback table keeps the converter, SSR and offline tests working with no network; failures route to an error action. When refreshes overlap, only the newest request may publish success or failure; an older completion cannot replace its rates or clear its in-flight status.

See docs/CALC-FORMAT.md and ARCHITECTURE.md for the full contract.

Exports

Every subpath a consumer can import, derived from the manifest by npm run docs:derive (npm run docs:check fails when the two drift):

| Import | Kind | Declarations | |---|---|---| | @jarenjs/calc | JavaScript | declared | | @jarenjs/calc/component | JavaScript | declared | | @jarenjs/calc/theme | JavaScript | declared | | @jarenjs/calc/styles/calc.css | asset | — | | @jarenjs/calc/schemas/financial-inputs.schema.json | schema | — | | @jarenjs/calc/schemas/jaren-calc-ast.schema.json | schema | — | | @jarenjs/calc/schemas/jaren-calc-state.schema.json | schema | — | | @jarenjs/calc/package.json | metadata | — |