Improve error message on mapreduce (sum)?

General Usage
1

hi

is it worth filing an issue that this error message could be improved?

julia> x = rand(3,4)
3×4 Array{Float64,2}:
 0.0393155  0.125126  0.019893  0.377598 
 0.785163   0.950731  0.968909  0.620597 
 0.999954   0.67239   0.397147  0.0414057

julia> sum(x,2)
ERROR: MethodError: objects of type Array{Float64,2} are not callable
Use square brackets [] for indexing an Array.
Stacktrace:
 [1] mapreduce_first(::Array{Float64,2}, ::Function, ::Int64) at ./reduce.jl:297
 [2] mapreduce(::Array{Float64,2}, ::Function, ::Int64) at ./reduce.jl:324
 [3] sum(::Array{Float64,2}, ::Int64) at ./reduce.jl:399
 [4] top-level scope at none:0

julia> sum(x,dims = 2)
3×1 Array{Float64,2}:
 0.561932448457142
 3.325399087609962
 2.110896964497427
2

I don’t think so, it would involve all methods that accept a callable as their first argument.

3

Note also that this is Julia 0.6’s notation, for which 0.7 prints has a helpful message:

julia> sum(x,2)
┌ Warning: `sum(a::AbstractArray, dims)` is deprecated, use `sum(a, dims=dims)` instead.
│   caller = top-level scope at none:0
└ @ Core none:0
3×1 Array{Float64,2}:
 1.6501660369150561
 2.2962250830923114
 2.6909858675277483
4

This is Julia 1.1

That warning message is exactly what I think should be displayed!!