v2.16.0

Get the text a spreadsheet would show, and read the currency and accounting
formats real files use. Additive and backward-compatible.

New

• NumFormat.format(value) renders a value the way a spreadsheet displays it.
  This is the renderer the TEXT formula function already used internally, now
  reachable from the public API, so the two always agree. It takes a num, a
  DateTime, a bool, a String or null; a date is converted to its serial
  number first, text comes back unchanged, and null renders as an empty string.
• Data.displayText applies a cell's own number format to its value. Reading a
  cell gives you the stored 1234.5; displayText gives you 1,234.50. This
  is what you want when rendering a sheet into your own table, grid or PDF, and
  it removed sixty lines of hand-written format-code handling from the example
  app, which is the point.

Fixed

• The built-in currency and accounting number formats were unmodelled and
  degraded to General. Ids 5 to 8 (currency) and 41 to 44 (accounting) are
  among the most common formats in real workbooks and are referenced by id
  rather than by a spelled-out code, so a file using one lost its formatting on
  the way through. They now read and write as themselves.
• Ids 23 to 36 are deliberately still unmapped. The spec reserves them and their
  meaning is locale dependent, so there is no single format code that is correct
  to write back. A file using one still opens: the id is preserved and the cell
  falls back rather than being rewritten as something else.

Docs

• The number formats guide covers rendering a cell as text and the built-in
  format ids, on the site and in the README.