better read the type from the parameter than to ask for it explicitly

src/states.jl

@@ -7,7 +7,7 @@ function phiplus(::Type{T}, d::Integer = 2) where {T<:Number}
     return LA.Hermitian(psi * psi' / T(d))
 end
 phiplus(d::Integer = 2) = phiplus(ComplexF64, d)
-export phiplus # SD: maybe call it ϕ_plus or even ϕp? There is also φ potentially.
+export phiplus
 
 "Produces the maximally entangled state ψ⁻ of local dimension `d`"
 function psiminus(::Type{T}, d::Integer = 2) where {T<:Number}
@@ -18,18 +18,16 @@ function psiminus(::Type{T}, d::Integer = 2) where {T<:Number}
     return LA.Hermitian(psi * psi' / T(d))
 end
 psiminus(d::Integer = 2) = psiminus(ComplexF64, d)
-export psiminus # SD: maybe call it ψ_minus or even ψm?
+export psiminus
 
 "Produces the isotropic state of local dimension `d` with visibility `v`"
-function isotropic(::Type{T}, v::Real = 1.0, d::Integer = 2) where {T<:Number}
+function isotropic(v::T, d::Integer = 2) where {T<:Real}
     return LA.Hermitian(v * phiplus(T, d) + (1 - v) * LA.I(d^2) / T(d^2))
 end
-isotropic(v::Real = 1.0, d::Integer = 2) = isotropic(ComplexF64, v, d)
 export isotropic
 
 "Produces the anti-isotropic state of local dimension `d` with visibility `v`"
-function anti_isotropic(::Type{T}, v::Real = 1.0, d::Integer = 2) where {T<:Number}
+function anti_isotropic(v::T, d::Integer = 2) where {T<:Real}
     return LA.Hermitian(v * psiminus(T, d) + (1 - v) * LA.I(d^2) / T(d^2))
 end
-anti_isotropic(v::Real = 1.0, d::Integer = 2) = anti_isotropic(ComplexF64, v, d)
 export anti_isotropic

test/nonlocal.jl

@@ -12,6 +12,6 @@
 end
 @testset "FP and FC notations" begin
     Aax = povm(mub(2))
-    @test correlation_tensor(isotropic(), Aax, Aax) ≈ Diagonal([1, 1, -1, 1])
-    @test correlation_tensor(isotropic(), Aax, Aax; marg = false) ≈ Diagonal([1, 1, -1])
+    @test correlation_tensor(isotropic(1.0), Aax, Aax) ≈ Diagonal([1, 1, -1, 1])
+    @test correlation_tensor(isotropic(1.0), Aax, Aax; marg = false) ≈ Diagonal([1, 1, -1])
 end