Calculator
A small expression calculator with a running history.
What it does
Type an arithmetic expression and see the result update live above the input as you type. Press Enter to commit it to the history list; click any history row to pull that result back into the input and keep working from it.
It handles + - * /, parentheses, decimals, unary signs, right-associative powers with ^, and % as “divide by 100”. Thousands separators are ignored, so pasting 1,250 * 3 works.
The history holds the eight most recent entries and lives in memory only; closing the app clears it.
Where the data comes from
Nowhere. Evaluation happens in the widget with a small hand-written parser.
Notably it does not use JavaScript’s eval. The app ships a content-security policy that forbids dynamic code evaluation, so an eval-based calculator would fail on every expression in the released build. The parser exists so the widget is safe by construction rather than by policy.
Limits
- Arithmetic only. No variables, functions, unit conversion or trigonometry.
- History is capped at eight entries and is not persisted between sessions.
- Results are displayed to the number of decimal places you choose (2, 4, 6 or 8); the underlying calculation is full floating point.