Warn about future reserved words #1048
Conversation
| val drop_array_future : unit -> unit | ||
| (** Hack: Remove the most recent warning about array as a future keyword. | ||
| Needed due to the {e other} hack of how we currently parse arrays. | ||
| *) |
There was a problem hiding this comment.
Oof. Wouldn't it have been easier to detect the keyword identifiers in Deprecation_analysis.ml?
There was a problem hiding this comment.
You could. I like it in the parser for a variety of reasons - it really highlights the structure of the change (I think we should also move all the keywords we parse as identifiers into a separate nonterminal for the same organizational reason, and just not emit the warning for those). This will capture every identifier automatically, but in deprecation analysis we'd need to do it separately for Variables, FunDecls, FunApps, ConDistApps, ... etc. I think it's where it should live naturally, as it is something that is true at parsing time and doesn't need any type information or other structure (same reason get_lp and increment_log_prog are in the lexer).
It just really, really highlights how bad the hack for parsing array[] notation is at the moment. We're basically trying to parse a variable which is indexed and then asserting after the fact that the variable's "name" is array and treating it's index notation as a dimension declaration. The fact that we need to unwind one of the warnings we generated as a result is hardly the worst thing about it.
Related to #953 and essentially the start of redoing stan-dev/stan#2712
Submission Checklist
Release notes
Warn about the following identifiers being reserved in a future version:
array,upper,lower,offset,multiplier.Copyright and Licensing
By submitting this pull request, the copyright holder is agreeing to
license the submitted work under the BSD 3-clause license (https://opensource.org/licenses/BSD-3-Clause)