Define Product ansatz

src/Qrochet.jl

@@ -6,4 +6,7 @@ export boundary, Open, Periodic
 export Product
 export MatrixProduct
 
+include("Quantum/Product.jl")
+export Product
+
 end

src/Quantum/Product.jl

@@ -0,0 +1,42 @@
+using Tenet
+
+struct Product{S<:Socket} <: Ansatz
+    wrap::TensorNetwork
+
+    function Product{S}(arrays; order = defaultorder(Product{S})) where {S}
+        if S <: State
+            all(==(1) ∘ ndims, arrays) || throw(DimensionMismatch("Product{State} is constructed with vectors"))
+        elseif S <: Operator
+            all(==(2) ∘ ndims, arrays) || throw(DimensionMismatch("Product{Operator} is constructed with matrices"))
+        end
+
+        n = length(arrays)
+
+        oinds = map(genoutsym, 1:n)
+        iinds = map(geninsym, 1:n)
+
+        tensors::Vector{Tensor} = map(enumerate(arrays)) do (i, array)
+            inds = map(order) do dir
+                if dir === :o
+                    oinds[i]
+                elseif dir === :i
+                    iinds[i]
+                end
+            end
+            Tensor(array, inds)
+        end
+
+        return new{S}(TensorNetwork(tensors))
+    end
+end
+
+defaultorder(::Type{Product{Scalar}}) = ()
+defaultorder(::Type{Product{State}}) = (:o,)
+defaultorder(::Type{Product{Operator}}) = (:i, :o)
+
+socket(::Type{<:Product{S}}) where {S} = S()
+
+# AbstractTensorNetwork interface
+for f in [:(Tenet.inds), :(Tenet.tensors), :(Base.size)]
+    @eval $f(ψ::Product; kwargs...) = $f(ψ.wrap; kwargs...)
+end