I was reviewing changes for Go 1.13 and I noticed that a new name "AllowNumberbars" was added to text/scanner:

AllowNumberbars = 1 << -allowNumberbars // if set, number literals may contain underbars as digit separators

We should consider renaming this before the Go 1.13 release for two reasons:

• Unless "numberbar" is a term of art I'm unaware of, the capitalization doesn't match current Go convention (such as in the name ScanRawStrings a few lines above): it should be AllowNumberBars.

• The name is derived from underbar as a name for the _ character which is also used in the documentation comment; I believe this usage is uncommon in American English as compared with underscore. Indeed, the updated spec uses underscore:

  For readability, an underscore character _ may appear after a base prefix or between successive digits; such underscores do not change the literal's value.

  So, despite being longer, I think that AllowNumberUnderscores (or AllowNumUnderscores?) would be better.

This name was added in CL 163079 and as far as I can tell, the name hasn't been debated yet. (Apologies if this shed was already painted.)

/cc @griesemer