Numeric type Improvements

[jeromesimeon]

The specification for Concerto has Integer (32bits) and Long (64bits): https://docs.accordproject.org/docs/model-properties.html#primitive-types

The current implementation supports neither. Integer and Long are treated interchangeably and internally represented as JavaScript numbers. Those are safe only up to MAX_SAFE_INTEGER which is 2^53-1 instead of 2^31-1 or 2^63-1.

Questions

• Should we try and implement this specification.
• Should we revise this, replace by a notion of big integer (then leave the behaviour to implementation -- this could be using the new big int for recent javascript implementations, be listed as safe only up to a MAX_SAFE number for some platforms?).
• Should we extend support to decimal numbers (or should we implement those on top of a big int?). Usecase: monetary amounts.

[dselman]

This is a nice description of how Avro deals with this: https://github.com/apache/avro/blob/master/lang/js/doc/Advanced-usage.md