tree f2a8a4d051ece09ee4ff4b4323913e87b3bc4db4
parent b19b41a0f9146864abb6c1f0642d70d2ba874b24
author Marcel van Lohuizen <mpvl@golang.org> 1589276299 +0200
committer Marcel van Lohuizen <mpvl@google.com> 1589404949 +0000

cue: use `_#` instead of `#_` for hidden definition

This slighly complicates the spec (though minimal).

The main benefit, though, is to allow for more straighforward
roundtrippability between languages. For instance, a language
may define an identifier starting with `_` that needs to be
mapped to a definition. Now, to avoid the definition from becoming
hidden, this `_` needs to be removed and bookkeeping in the form
of attributes need to be added to preserve the name in a round trip.

With the rewording, the `#` marks the start of the identifier and
an optionally preceding `_` indicates hidden independent of this.
This allows the Go mapping to preserve naming without any
rewrites, for instance.

The spec now also more clearly distinguishes between
hidden and definition fields.

Change-Id: Ic7bdcc3527d0639b0943246ef0af629c6a477493
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/5980
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>