Add way to get module of variable from an UndefVarError

[djsegal]

Repeat of Discourse Post:

• Way to get module of undef variable?

---

From Post:

If you do:

cur_error = nothing 

try 
  foo(bar::Main.baz) = "Rambo"
catch tmp_error
  cur_error = tmp_error
end

which gives

> cur_error
UndefVarError(:baz)

> cur_error.var
:baz

---

The thing I'm kind of curious about is if there is a way to get the module that should have :baz in it (i.e. Main)?

[vchuravy]

Again please do not double post. Discourse is meant for questions like this and by double posting you are sending everyone two emails.

[vtjnash]

I agree - don’t double post. But this one seems like a good idea, and probably not bad as a first PR.

[djsegal]

Won't double post in the future.

The reason for this one though is because:

• it didn't get traction on Discourse
• then i realized it's probably because it would have to be implemented.

Is this not a correct workflow?

(i.e. avoid making issues on github as long as possible. but do so once you realize it's the way to go?)

[djsegal]

Also @vtjnash, what spec should I build this under?

Do you add a :mod field to UndefVarError that stores a symbol representation of the module?

// or do you just store the module object directly?

[vtjnash]

it didn't get traction on Discourse

Also probably just slow for the holidays. This could have been opened straight as a feature request on github. Posting an update on Discourse to say that you had turned it into an issue would also be good (to try to avoid splitting any discussion, and avoid the appearance of double posting).

I recommend just storing the Module reference directly in a new field (and leave it uninitialized for local variables - or better yet store the Method)

[JeffBezanson]

avoid making issues on github as long as possible

+1 to what vtjnash said, and I'll add that I mostly read github issues so I'm more likely to see things here. I will never tell anybody not to open a github issue --- if an issue is inappropriate for whatever reason it is very quick and easy to close one.