Replace previous Ansatz for Quantum struct

Project.toml

@@ -6,7 +6,9 @@ version = "0.1.0"
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 Tenet = "85d41934-b9cd-44e1-8730-56d86f15f3ec"
+ValSplit = "0625e100-946b-11ec-09cd-6328dd093154"
 
 [compat]
 Tenet = "0.5"
+ValSplit = "0.1"
 julia = "1.9"

src/Quantum/Ansatz.jl → src/Ansatz.jl

@@ -1,6 +1,6 @@
 using Tenet
 
-abstract type Ansatz <: Tenet.AbstractTensorNetwork end
+abstract type Ansatz end
 
 abstract type Socket end
 struct Scalar <: Socket end
@@ -10,14 +10,25 @@ struct Operator <: Socket end
 function socket end
 socket(::A) where {A<:Ansatz} = socket(A)
 
+function socket(q::Quantum)
+    _sites = sites(q)
+    if isempty(_sites)
+        Scalar()
+    elseif all(!isdual, _sites)
+        State()
+    else
+        Operator()
+    end
+end
+
 abstract type Boundary end
 struct Open <: Boundary end
 struct Periodic <: Boundary end
 
 function boundary end
 boundary(::A) where {A<:Ansatz} = boundary(A)
 
-Base.summary(io::IO, tn::A) where {A<:Ansatz} = print(io, "$A(n=$(length(tensors(tn))))")
+Base.summary(io::IO, tn::A) where {A<:Ansatz} = print(io, "$A (n=$(length(tensors(tn))))")
 Base.show(io::IO, tn::A) where {A<:Ansatz} = Base.summary(io, tn)
 
 # helpers

src/Qrochet.jl

@@ -1,12 +1,17 @@
 module Qrochet
 
-include("Quantum/Ansatz.jl")
+include("Quantum.jl")
+export Site, site_str, isdual
+export ninputs, noutputs, sites
+export Quantum
+
+include("Ansatz.jl")
 export socket, Scalar, State, Operator
 export boundary, Open, Periodic
 export Product
 export MatrixProduct
 
-include("Quantum/Product.jl")
+include("Ansatz/Product.jl")
 export Product
 
 end

src/Quantum.jl

@@ -0,0 +1,82 @@
+using Tenet
+
+"""
+    Site(id[, dual = false])
+    site"id"
+
+Represents a physical index.
+
+# Unresolved questions
+
+  - Should we store here some information about quantum numbers?
+"""
+struct Site
+    id::Int
+    dual::Bool
+
+    Site(id, dual = false) = new(id, dual)
+end
+
+isdual(site::Site) = site.dual
+Base.show(io::IO, site::Site) = print(io, "$(site.id)$(site.dual ? "†" : "")")
+Base.adjoint(site::Site) = Site(site.id, !site.dual)
+
+macro site_str(str)
+    m = match(r"^(\d+)(')$", str)
+    if isnothing(m)
+        error("Invalid site string: $str")
+    end
+
+    id = parse(Int, m.captures[1])
+    dual = m.captures[2] == "'"
+
+    quote
+        Site($id, $dual)
+    end
+end
+
+"""
+    Quantum
+
+Tensor Network with a notion of "causality". This leads to the notion of sites and directionality (input/output).
+
+# Notes
+
+  - Indices are referenced by `Site`s.
+"""
+struct Quantum
+    tn::TensorNetwork
+
+    # WARN keep them synchronized
+    siteinds::Dict{Site,Symbol}
+    sitetensors::Dict{Site,Tensor}
+
+    function Quantum(tn::TensorNetwork, sites::Dict{Site,Symbol})
+        for (site, index) in sites
+            if !haskey(tn.indexmap, index)
+                error("Index $index not found in TensorNetwork")
+            elseif index ∉ inds(tn, set = :open)
+                error("Index $index must be open")
+            end
+        end
+
+        sitetensors = map(sites) do (site, index)
+            site => tn[index]
+        end |> Dict{Site,Tensor}
+
+        new(tn, sites, sitetensors)
+    end
+end
+
+# TODO (@mofeing) Return `copy`?
+Tenet.TensorNetwork(q::Quantum) = q.tn
+
+ninputs(q::Quantum) = count(isdual, keys(q.sites))
+noutputs(q::Quantum) = count(!isdual, keys(q.sites))
+
+Base.summary(io::IO, q::Quantum) = print(io, "$(length(q.tn.tensormap))-tensors Quantum")
+Base.show(io::IO, q::Quantum) = print(io, "Quantum (inputs=$(ninputs(q)), outputs=$(noutputs(q)))")
+
+sites(tn::Quantum) = collect(keys(tn.siteinds))
+
+Base.getindex(q::Quantum, site::Site) = q.siteinds[site]

test/runtests.jl

@@ -1,6 +1,5 @@
 using Test
 using Qrochet
-using OMEinsum
 
 @testset "Unit tests" verbose = true begin end