@deckyard/sheets

Read, edit and write OpenDocument (.ods), Office Open XML (.xlsx), Gnumeric and delimited text from Jennifer, over one Workbook model of typed cells. It translates formulas between the ODS and XLSX dialects, evaluates about 110 spreadsheet functions, applies number formats and styles, streams sheets too large to hold in memory, and exports to HTML, JSON and PDF.

Documentation

Install

jvc add @deckyard/sheets

jvc vendors the deck's src/ into vendor/deckyard/sheets/. Without jvc, unpack src/ from a release archive (deckyard-sheets-<version>.tar.gz) into that directory.

Requires Jennifer 0.25.0 or newer. No capabilities: no network, subprocesses or database. open and save use fs; every codec also has a bytes entry point.

Example

import "@deckyard/sheets/" as sheet;

def wb as sheet.Workbook init sheet.open("sales.xlsx");
def s as sheet.Sheet init sheet.sheetByName($wb, "Q3");

for (def line in sheet.rows($s)) {
    io.printf("%s: %f\n", sheet.asString($line[0]), sheet.asNumber($line[1]));
}

$s = sheet.addRow($s, [sheet.text("East"), sheet.number(1510.25)]);
$wb = sheet.putSheet($wb, $s);
sheet.save($wb, "sales.ods");     # the extension picks the format

Development

tools/check-all.sh                   # the whole gate, as CI runs it
jennifer test src/sheets_test.j      # the test suite
tools/check-extra.sh                 # LibreOffice / Gnumeric validation and oracles
tools/pack.sh dist                   # the release archive

CI also opens every written file in LibreOffice and compares the values back (.github/workflows/validate.yml): the only check that catches a file this deck reads but a real application rejects.

Licence

LGPL-3.0-only, see LICENSE. Copyright (C) 2026 mplx <mplx@jennifer-lang.dev>.