Added indexing

src/Indexing.jl

@@ -0,0 +1,21 @@
+
+size(a::MultiValue) = size(a.array)
+
+length(a::MultiValue) = length(a.array)
+
+@propagate_inbounds function getindex(
+    a::MultiValue{S,T,N}, I::Vararg{Integer,N}) where {S,T,N}
+    @inbounds a.array[I...]
+end
+
+@propagate_inbounds function getindex(a::MultiValue, i::Integer)
+    @inbounds a.array[i]
+end
+
+eltype(a::Type{MultiValue{S,T,N,L}}) where {S,T,N,L} = T
+
+iterate(a::MultiValue) = iterate(a.array)
+
+iterate(a::MultiValue, state) = iterate(a.array, state)
+
+eachindex(a::MultiValue) = eachindex(a.array)

src/TensorValues.jl

@@ -1,6 +1,7 @@
 module TensorValues
 
 using StaticArrays
+using Base: @propagate_inbounds
 
 export MultiValue
 export TensorValue
@@ -12,10 +13,15 @@ export det, inv
 import Base: show
 import Base: zero, one
 import Base: +, -, *, /, \, ==, ≈
+import Base: getindex, iterate, eachindex
+import Base: size, length, eltype
+
 import LinearAlgebra: det, inv
 
 include("Types.jl")
 
+include("Indexing.jl")
+
 include("Operations.jl")
 
 end # module

test/IndexingTests.jl

@@ -0,0 +1,33 @@
+module IndexingTests
+
+using Test
+using TensorValues
+
+a = (3,4,5,1)
+
+v = VectorValue{4}(a)
+
+@test eltype(v) == Int
+@test eltype(typeof(v)) == Int
+
+@test size(v) == (4,)
+@test length(v) == 4
+
+for (k,i) in enumerate(eachindex(v))
+  @test v[i] == a[k]
+end
+
+t = TensorValue{2}(a)
+
+@test size(t) == (2,2)
+@test length(t) == 4
+
+for (k,i) in enumerate(eachindex(t))
+  @test t[i] == a[k]
+end
+
+@test t[2,1] == 4
+
+@test t[2] == 4
+
+end # module IndexingTests

test/runtests.jl

@@ -11,4 +11,8 @@ end
   include("OperationsTests.jl")
 end
 
+@testset "IndexingTests" begin
+  include("IndexingTests.jl")
+end
+
 end # module TensorValuesTests