I feel like I’m missing something obvious, but why doesn’t this work:

```
julia> immutable Counts
j::Int32
i::Int32
nij::Int64
end
julia> # allocate something
test = Array{Counts,1}()
0-element Array{Counts,1}
julia> for i in 1:10
push!(test,Counts(rand(Int32),rand(Int32),rand(Int64)))
end
julia> # is x < y ?
isless(x::Counts, y::Counts) = (x.j < y.j) || ((x.j == y.j) && (x.i < y.i)) || ((x.j == y.j) && (x.i == y.i) && (x.nij < y.nij))
isless (generic function with 1 method)
julia> sort!(test)
ERROR: MethodError: no method matching isless(::Counts, ::Counts)
in sort!(::Array{Counts,1}, ::Int64, ::Int64, ::Base.Sort.InsertionSortAlg, ::Base.Order.ForwardOrdering) at ./sort.jl:222
in sort!(::Array{Counts,1}, ::Int64, ::Int64, ::Base.Sort.MergeSortAlg, ::Base.Order.ForwardOrdering, ::Array{Counts,1}) at ./sort.jl:311
in sort!(::Array{Counts,1}, ::Base.Sort.MergeSortAlg, ::Base.Order.ForwardOrdering) at ./sort.jl:405
in sort!(::Array{Counts,1}) at ./sort.jl:414
```

I define a simple immutable type, and just want to sort an array of them

in lexicographic order.

Am I defining isless wrong somehow?

Thanks,

Craig