Identity ex-info exceptions as being thrown from rewrite-clj

[lread]

Problem/Opportunity
Rewrite-clj throws ex-info exceptions.
It would be nice if a caller could easily tell if they came from rewrite-clj.

Proposed Solution
@borkdude suggested adding :type :rewrite-clj to ex-data.

Alternative Solutions
None at this time.

Action
I can follow up with a PR sometime soon.

[borkdude]

A namespaced keyword would allow usage with derive. This is what I've done in SCI: :sci/error for general errors.

[lread]

A namespaced keyword would allow usage with derive. This is what I've done in SCI: :sci/error for general errors.

Cool, thanks, I'll take a peek at sci for inspiration.

[lread]

While I'm looking at exceptions I've started to look at this one.

Following sci's example we'll have a base exception :type of :rewrite-clj/error.

It will have descendants:

• rewrite-clj.error/parse will have descendants:
  • rewrite-clj.error/unmatched-delimiter
  • rewrite-clj.error/eof (could optionally distinguish different reasons for eof with descendants, but probably won't yet)
  • rewrite-clj.error/invalid will have descendants
    • rewrite-clj.error/invalid-keyword
    • rewrite-clj.error/invalid-symbol
    • rewrite-clj.error/invalid-namespaced-map
    • ...

I'll review and update as I work my way through what rewrite-clj currently throws.
(and what our usage of tools.reader currently throws, for that matter).

As always, feedback and ideas are welcome.

[lread]

An alternative to being very granular for invalid errors is to include what rewrite-clj was trying to parse as a separate map entry in the ex-info data. Our node tag is not terribly granular so this might send me to finally look at #114.