Define conj for AbstractITensorNetwork and @preserve_graph macro

Project.toml

@@ -1,7 +1,7 @@
 name = "ITensorNetworks"
 uuid = "2919e153-833c-4bdc-8836-1ea460a35fc7"
 authors = ["Matthew Fishman <[email protected]>, Joseph Tindall <[email protected]> and contributors"]
-version = "0.11.10"
+version = "0.11.11"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
@@ -19,6 +19,7 @@ IsApprox = "28f27b66-4bd8-47e7-9110-e2746eb8bed7"
 IterTools = "c8e1da08-722c-5040-9ed9-7db0dc04731e"
 KrylovKit = "0b1a1467-8014-51b9-945f-bf0ae24f4b77"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
 NDTensors = "23ae76d9-e61a-49c4-8f12-3f1a16adf9cf"
 NamedGraphs = "678767b0-92e7-4007-89e4-4527a8725b19"
 PackageExtensionCompat = "65ce6f38-6b18-4e1d-a461-8949797d7930"
@@ -63,6 +64,7 @@ ITensors = "0.6.8"
 IsApprox = "0.1"
 IterTools = "1.4.0"
 KrylovKit = "0.6, 0.7"
+MacroTools = "0.5"
 NDTensors = "0.3"
 NamedGraphs = "0.6.0"
 OMEinsumContractionOrders = "0.8.3"

src/abstractitensornetwork.jl

@@ -39,6 +39,7 @@ using ITensors:
 using ITensorMPS: ITensorMPS, add, linkdim, linkinds, siteinds
 using .ITensorsExtensions: ITensorsExtensions, indtype, promote_indtype
 using LinearAlgebra: LinearAlgebra, factorize
+using MacroTools: @capture
 using NamedGraphs: NamedGraphs, NamedGraph, not_implemented
 using NamedGraphs.GraphsExtensions:
   ⊔, directed_graph, incident_edges, rename_vertices, vertextype
@@ -138,6 +139,30 @@ function setindex_preserve_graph!(tn::AbstractITensorNetwork, value, vertex)
   return tn
 end
 
+# TODO: Move to `BaseExtensions` module.
+function is_setindex!_expr(expr::Expr)
+  return is_assignment_expr(expr) && is_getindex_expr(first(expr.args))
+end
+is_setindex!_expr(x) = false
+is_getindex_expr(expr::Expr) = (expr.head === :ref)
+is_getindex_expr(x) = false
+is_assignment_expr(expr::Expr) = (expr.head === :(=))
+is_assignment_expr(expr) = false
+
+# TODO: Define this in terms of a function mapping
+# preserve_graph_function(::typeof(setindex!)) = setindex!_preserve_graph
+# preserve_graph_function(::typeof(map_vertex_data)) = map_vertex_data_preserve_graph
+# Also allow annotating codeblocks like `@views`.
+macro preserve_graph(expr)
+  if !is_setindex!_expr(expr)
+    error(
+      "preserve_graph must be used with setindex! syntax (as @preserve_graph a[i,j,...] = value)",
+    )
+  end
+  @capture(expr, array_[indices__] = value_)
+  return :(setindex_preserve_graph!($(esc(array)), $(esc(value)), $(esc.(indices)...)))
+end
+
 function ITensors.hascommoninds(tn::AbstractITensorNetwork, edge::Pair)
   return hascommoninds(tn, edgetype(tn)(edge))
 end
@@ -148,7 +173,7 @@ end
 
 function Base.setindex!(tn::AbstractITensorNetwork, value, v)
   # v = to_vertex(tn, index...)
-  setindex_preserve_graph!(tn, value, v)
+  @preserve_graph tn[v] = value
   for edge in incident_edges(tn, v)
     rem_edge!(tn, edge)
   end
@@ -297,12 +322,12 @@ function ITensors.replaceinds(
   @assert underlying_graph(is) == underlying_graph(is′)
   for v in vertices(is)
     isassigned(is, v) || continue
-    setindex_preserve_graph!(tn, replaceinds(tn[v], is[v] => is′[v]), v)
+    @preserve_graph tn[v] = replaceinds(tn[v], is[v] => is′[v])
   end
   for e in edges(is)
     isassigned(is, e) || continue
     for v in (src(e), dst(e))
-      setindex_preserve_graph!(tn, replaceinds(tn[v], is[e] => is′[e]), v)
+      @preserve_graph tn[v] = replaceinds(tn[v], is[e] => is′[e])
     end
   end
   return tn
@@ -361,13 +386,31 @@ end
 
 LinearAlgebra.adjoint(tn::Union{IndsNetwork,AbstractITensorNetwork}) = prime(tn)
 
-#dag(tn::AbstractITensorNetwork) = map_vertex_data(dag, tn)
-function ITensors.dag(tn::AbstractITensorNetwork)
-  tndag = copy(tn)
-  for v in vertices(tndag)
-    setindex_preserve_graph!(tndag, dag(tndag[v]), v)
+function map_vertex_data(f, tn::AbstractITensorNetwork)
+  tn = copy(tn)
+  for v in vertices(tn)
+    tn[v] = f(tn[v])
   end
-  return tndag
+  return tn
+end
+
+# TODO: Define `@preserve_graph map_vertex_data(f, tn)`
+function map_vertex_data_preserve_graph(f, tn::AbstractITensorNetwork)
+  tn = copy(tn)
+  for v in vertices(tn)
+    @preserve_graph tn[v] = f(tn[v])
+  end
+  return tn
+end
+
+function Base.conj(tn::AbstractITensorNetwork)
+  # TODO: Use `@preserve_graph map_vertex_data(f, tn)`
+  return map_vertex_data_preserve_graph(conj, tn)
+end
+
+function ITensors.dag(tn::AbstractITensorNetwork)
+  # TODO: Use `@preserve_graph map_vertex_data(f, tn)`
+  return map_vertex_data_preserve_graph(dag, tn)
 end
 
 # TODO: should this make sure that internal indices
@@ -442,9 +485,7 @@ function NDTensors.contract(
   for n_dst in neighbors_dst
     add_edge!(tn, merged_vertex => n_dst)
   end
-
-  setindex_preserve_graph!(tn, new_itensor, merged_vertex)
-
+  @preserve_graph tn[merged_vertex] = new_itensor
   return tn
 end
 
@@ -533,13 +574,8 @@ function LinearAlgebra.factorize(
     add_edge!(tn, X_vertex => nX)
   end
   add_edge!(tn, Y_vertex => dst(edge))
-
-  # tn[X_vertex] = X
-  setindex_preserve_graph!(tn, X, X_vertex)
-
-  # tn[Y_vertex] = Y
-  setindex_preserve_graph!(tn, Y, Y_vertex)
-
+  @preserve_graph tn[X_vertex] = X
+  @preserve_graph tn[Y_vertex] = Y
   return tn
 end
 

test/test_itensornetwork.jl

@@ -175,6 +175,17 @@ const elts = (Float32, Float64, Complex{Float32}, Complex{Float64})
       return inds -> itensor(randn(rng, elt, dim.(inds)...), inds)
     end
     @test eltype(ψ[first(vertices(ψ))]) == elt
+
+    ψc = conj(ψ)
+    for v in vertices(ψ)
+      @test ψc[v] == conj(ψ[v])
+    end
+
+    ψd = dag(ψ)
+    for v in vertices(ψ)
+      @test ψd[v] == dag(ψ[v])
+    end
+
     rng = StableRNG(1234)
     ψ = ITensorNetwork(g; kwargs...) do v
       return inds -> itensor(randn(rng, dim.(inds)...), inds)