check for unused bindings

[ZacLN]

Needs some finessing:

• special handling for loops
• do backwards/forward looks for overwritten bindings

[pfitzseb]

Hm, but isn't that in line with how Julia's loops work?

julia> for i in 1:3
         if i > 2
           println(x)
         end
         x = i
       end
ERROR: UndefVarError: x not defined

So we only need to check if the variable being assigned is used in a enclosing scope, as you mention below?

[ZacLN]

Hmm, that i did not know!

EDIT: Though thankfully the it doesn't actually check this. For info, these checks don't run on the toplevel scope so you need to wrap the above example in a function

[pfitzseb]

Doesn't matter whether it's in a top-level scope or not, afaict:

julia> function f()
         for i in 1:3
           if i > 2
             println(x)
           end
           x=i
         end
       end
f (generic function with 1 method)

julia> f()
ERROR: UndefVarError: x not defined

[ZacLN]

I meant for the StaticLint checks