Added Dict constructor from tuple array

[kmsquire]

Right now, we can get an array of tuples from a Dictionary via collect, but there's no constructor from such an array. This pull request remedies that.

julia> a = [("A",1),("B",2),("C",4)]
3-element Array{(ASCIIString,Int64),1}:
 ("A",1)
 ("B",2)
 ("C",4)

julia> Dict(a)
["B"=>2,"C"=>4,"A"=>1]

julia> typeof(ans)
Dict{ASCIIString,Int64} (constructor with 2 methods)

[JeffBezanson]

Good idea, but it might as well work for any iterator that generates 2-tuples. This is also probably not a good case for zip since there might be a very large number of things to zip.

I would do it like this:

    # inner ctor
    function Dict(kv)
        h = Dict{K,V}()
        for (k,v) in kv
            h[k] = v
        end
        return h
    end
end

Dict(ks, vs) = Dict{Any,Any}(zip(ks,vs))
# etc.

Once we merge @loladiro 's tuples branch zip(x,y) will be as fast as anything.

[JeffBezanson]

added in 93274a3

[kmsquire]

Thanks!

On Fri, Nov 22, 2013 at 1:48 PM, Jeff Bezanson notifications@github.comwrote:

added in 93274a393274a3

—
Reply to this email directly or view it on GitHubhttps://github.com//pull/4872#issuecomment-29111843
.

[coveralls]

Changes Unknown when pulling 56ff0db on kms/dict_from_tuple_array into * on master*.

[jiahao]

^ over 40 million seconds late...?

[tkelman]

We don't even have coveralls turned on for base Julia. If you look at the list of files it's a bunch of ruby having to do with paypal? This has happened before, I think coveralls is hitting some hash collision or something.