BigInt + Scale

The most simple implementation of BigDecimal would be a record with two fields: a BigInt and a scale (power of 10). The industry already uses something along these lines for currency amounts, which are often stored as a BigInt number of "micros".

If we're only concerned about representation, and not math, an alternative to the BigDecimal proposal altogether would be to establish a precedent for how to represent the BitInt/Scale pair. For example, we could add a .format overload to Intl.NumberFormat method that takes an object literal with a BigInt and a scale. Something like,

new Intl.NumberFormat().format({
  mantissa: // a BigInt
  scale: // a power of 10 (probably a Number)
});

We could establish that convention as how BigDecimals are represented in the language, without actually introducing a BitInt type.

Start by reading the proposed BigInt-and-scale representation and the suggested Intl.NumberFormat.format overload in this issue. No file or test is identified, and completion would require deciding whether this representation convention should replace or complement the BigDecimal proposal.