S-Calc

A calculator you write in a note. Put expressions in an s-calc code block and each line's result appears on the right, in your theme's accent color, updating live as you type.

By Abdulkader Safi.

Usage

Add a fenced block with the s-calc language:

```s-calc
Price: $10
Fee: 4 GBP in Euro
sum in USD - 4%

next friday + 2 weeks
20 ml in tea spoons
20% of what is 30 cm
```

Each line is evaluated in order. The result shows to the right of the line.

Preview

What it can do

• Arithmetic with parentheses: 2 + 3 * 4, (10 + 5) / 3.
• Labels and variables: Price: 10 or Price = 10, then reuse Price on a later line.
• sum and prev: sum is the running total of the lines above, prev is the previous line's result.
• Percentages: 120 - 15%, 20% of 30, 20% of what is 30.
• Units and conversion: 20 ml in tea spoons, 5 km in miles, 2 kg in lb.
• Currencies with live rates: 4 GBP in Euro, 100 USD in JPY, 50 KWD in LBP. Every currency the rate feed returns is supported, referenced by ISO code (USD, EUR, GBP, KWD, LBP, …) or common name (dollar, euro, pound).
• Dates in plain language: next friday, next friday + 2 weeks, today + 90 days.

Blank lines and lines starting with # or // are ignored.

Notes

• Currency rates are fetched once per session from a free public endpoint (no API key). Currency lines fill in as soon as the rates load.
• For inches, write inch (the bare word in is used for conversions).
• Multi-word currency names may not parse; use the ISO code (e.g. LBP).

Develop

Requires Node.js v18 or newer.

npm install      # install dependencies
npm run dev      # rebuild main.js on change
npm run build    # production build
npm run test     # run the engine self-check
npm run lint     # lint with ESLint

For local testing, develop inside your vault at VaultFolder/.obsidian/plugins/s-calc/, then enable the plugin in Settings → Community plugins and reload.

License

Released under the MIT license. See LICENSE.