@vitral/spreadsheet

A spreadsheet with no framework in it: cells, A1 references, formulas over them, and the graph that says what has to be worked out again when one changes. Part of Vitral.

import { createSheet } from '@vitral/spreadsheet/engine';

const sheet = createSheet({
    cells: { A1: 'Desk', B1: 320, C1: 2, D1: '=B1*C1', D2: '=SUM(D1:D1)' }
});

sheet.value({ row: 0, col: 3 }); // 640
sheet.setInput({ row: 0, col: 2 }, '5');
sheet.value({ row: 0, col: 3 }); // 1600

A sheet is a map of addresses to what was typed into them, and everything else is worked out from it — so it survives JSON, comes back the same, and can be tested without a document in sight.

• Formulas: the usual operators with the usual strengths, rectangles (A1:C9), $ to pin a reference, and sixty-three functions — SUM, AVERAGE, IF, COUNTIF, VLOOKUP, INDEX, MATCH, the text ones, and dates counted the way every spreadsheet counts them.
• Only what changed: an edit works out the cells that followed from it, not the sheet.
• Errors are values: #DIV/0!, #NAME?, #CIRCULAR! and the rest travel through arithmetic the way they should, and a formula that does not read is kept as it was typed rather than refused.
• Editing: fill with the references carried, a run of numbers carried on, tab-separated paste and copy, formats, and undo.

Licensed LGPL-3.0-or-later.