Why can you not make it into a function?
function foo!(spec::Symbol, A, i)
A[i,spec] = 1
end
function foo!{T<:Real}(spec::Vector{(Symbol,T), A, i)
@assert(isapprox(sum(map(x -> x[2],spec)),1))
for (obs,prob) = spec
A[i,obs] = prob
end
A[i,spec] = 1
end
foo!(spec, A, i) = error(" ...")
that way your code will be cleaner too:
foo!(spec, A, i)
In Julia, when you use an isa, then ask yourself whether it might not be
cleaner using methods instead.
If that is not an option you have to make a function for the check...
On Mon, 2015-04-13 at 14:06, Tamas Papp <[email protected]> wrote:
> Hi,
>
> I had some code like
>
> if isa(spec, Symbol)
> A[i,spec] = 1
> elseif isa(spec, Vector{(Symbol,Float64)})
> @assert(isapprox(sum(map(x -> x[2],spec)),1))
> for (obs,prob) = spec
> A[i,obs] = prob
> end
> else
> error("don't know how to parse $spec for aggregation")
> end
>
> but got bittenby a spec = [(:I,0),(:U,1)] which is valid for my problem,
> so I realized I need to test for Real, not Float64.
>
> If this was a method of a generic fuction, I could simply use T <: Real
> and then use Vector{(Symbol,T)} in the type signature --- but it isn't,
> so I would be interested in how to test for the condition in the subject
> line in an if branch.
>
> isa(Vector{(Symbol,Real)}) won't work, my understanding is that this is
> because of invariance.
>
> Best,
>
> Tamas
