Fix result_type issues (#211)

Project.toml

@@ -1,6 +1,6 @@
 name = "Distances"
 uuid = "b4f34e82-e78d-54a5-968a-f98e89d6e8f7"
-version = "0.10.1"
+version = "0.10.2"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/generic.jl

@@ -38,6 +38,7 @@ result_type(f, a::Type, b::Type) = typeof(f(oneunit(a), oneunit(b))) # don't req
 
 _eltype(a) = __eltype(Base.IteratorEltype(a), a)
 _eltype(::Type{T}) where {T} = eltype(T) === T ? T : _eltype(eltype(T))
+_eltype(::Type{Union{Missing, T}}) where {T} = Union{Missing, T}
 
 __eltype(::Base.HasEltype, a) = _eltype(eltype(a))
 __eltype(::Base.EltypeUnknown, a) = _eltype(typeof(first(a)))

src/haversine.jl

@@ -60,3 +60,5 @@ function (dist::SphericalAngle)(x, y)
 end
 
 spherical_angle(x, y) = SphericalAngle()(x, y)
+
+result_type(::Union{Haversine, SphericalAngle}, ::Type, ::Type) = Float64

src/metrics.jl

@@ -315,8 +315,8 @@ function _evaluate(dist::UnionMetrics, a::Number, b::Number, p)
 end
 
 eval_start(d::UnionMetrics, a, b) = _eval_start(d, _eltype(a), _eltype(b))
-_eval_start(d, ::Type{Ta}, ::Type{Tb}) where {Ta,Tb} =
-    _eval_start(d, _eltype(Ta), _eltype(Tb), parameters(d))
+_eval_start(d::UnionMetrics, ::Type{Ta}, ::Type{Tb}) where {Ta,Tb} =
+    _eval_start(d, Ta, Tb, parameters(d))
 _eval_start(d::UnionMetrics, ::Type{Ta}, ::Type{Tb}, ::Nothing) where {Ta,Tb} =
     zero(typeof(eval_op(d, oneunit(Ta), oneunit(Tb))))
 _eval_start(d::UnionMetrics, ::Type{Ta}, ::Type{Tb}, p) where {Ta,Tb} =

test/test_dists.jl

@@ -182,6 +182,7 @@ end
                          ([4.0, 5.0, 6.0, 7.0], [3. 8.; 9. 1.0]))
             x, y = T.(_x), T.(_y)
             for (x, y) in ((x, y),
+                           (convert(Array{Union{Missing, T}}, x), convert(Array{Union{Missing, T}}, y)),
                            ((Iterators.take(x, 4), Iterators.take(y, 4))), # iterator
                            (((x[i] for i in 1:length(x)), (y[i] for i in 1:length(y)))), # generator
                           )
@@ -640,6 +641,13 @@ end
 
     test_pairwise(SqMahalanobis(Q), X, Y, T)
     test_pairwise(Mahalanobis(Q), X, Y, T)
+
+    m, nx, ny = 2, 8, 6
+
+    X = rand(T, m, nx)
+    Y = rand(T, m, ny)
+    test_pairwise(Haversine(), X, Y, T)
+    test_pairwise(SphericalAngle(), X, Y, T)
 end
 
 function test_scalar_pairwise(dist, x, y, T)