Can we/should we somehow derive a unique, stable-with-time, number for each node, each string enum constant.

[Yoric]

Having unique, stable-with-time numeric identifiers for each node and (in a separate namespace) each string enum value would be useful for the following purposes:

1. if these numbers are standardized, we could entirely avoid shipping interface names, string enum constants, either in static dictionaries or in compressed files;
2. regardless of standardization, this would give us a simple base for generating a Finite State Machine for decoding token that would keep working even with future versions of the webidl.

Cc @syg . Note that this spec has no real implication on syntax, so would probably be part of the container format.

[Yoric]

So, one way to implement this with or without standardization would simply to have a file that maps each string enum constant to a value, each identifier to a value, possibly with some static analysis/commit hook that ensures that we never remove/alter existing values.

To actually standardize this, we could either manually give a number to each value, with the same guarantee, or come up with a spec to derive the numbers from each successive version of the webidl. For instance:

1. initially
   • "" (the null interface) is assigned 0;
   • "" (the null string enum) is assigned 0, regardless of string enum;
2. after each new spec
   • each existing number is maintained;
   • all new interface names are ranked by alphanumerical order and assigned unassigned interface numbers, by increasing order;
   • for each string enum:
     • all new constants are ranked by alphanumerical order and assigned unassigned constant values for this string enum, by increasing order.

The only real drawbacks, I believe, are that:

• we can never, ever get rid of a number;
• we need to specify updates to the webidl as diffs (or at least extract the diffs).