ITensor · mtfishman · Jun 24, 2026 · Jun 24, 2026 · Jun 24, 2026 · Jun 24, 2026
diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "ITensorBase"
 uuid = "4795dd04-0d67-49bb-8f44-b89c448a1dc7"
-version = "0.7.0"
+version = "0.8.0"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
 
 [workspace]
@@ -52,7 +52,7 @@ Mooncake = "0.4.202, 0.5"
 OrderedCollections = "1.6"
 Random = "1.10"
 SimpleTraits = "0.9.4"
-TensorAlgebra = "0.10"
+TensorAlgebra = "0.11"
 TensorOperations = "5.3.1"
 TermInterface = "2"
 TupleTools = "1.6"

diff --git a/docs/Project.toml b/docs/Project.toml
@@ -12,9 +12,9 @@ path = ".."
 
 [compat]
 Documenter = "1"
-ITensorBase = "0.7"
+ITensorBase = "0.8"
 ITensorFormatter = "0.2.27"
 Literate = "2"
 MatrixAlgebraKit = "0.2, 0.3, 0.4, 0.5, 0.6"
-TensorAlgebra = "0.10"
+TensorAlgebra = "0.11"
 Test = "1.10"
diff --git a/examples/Project.toml b/examples/Project.toml
@@ -6,5 +6,5 @@ MatrixAlgebraKit = "6c742aac-3347-4629-af66-fc926824e5e4"
 path = ".."
 
 [compat]
-ITensorBase = "0.7"
+ITensorBase = "0.8"
 MatrixAlgebraKit = "0.2, 0.3, 0.4, 0.5, 0.6"
diff --git a/ext/ITensorBaseMooncakeExt/ITensorBaseMooncakeExt.jl b/ext/ITensorBaseMooncakeExt/ITensorBaseMooncakeExt.jl
@@ -1,14 +1,12 @@
 module ITensorBaseMooncakeExt
 
-using ITensorBase: AbstractITensor, NamedUnitRange, blockedperm_nameddims, dimnames,
-    dimnames_setdiff, inds, name, to_inds, uniquename
+using ITensorBase: AbstractITensor, NamedUnitRange, dimnames, dimnames_setdiff, inds, name,
+    nameperm, to_inds, uniquename
 using Mooncake: Mooncake, @zero_derivative, DefaultCtx
-using TensorAlgebra: blockedperm
 
 Mooncake.tangent_type(::Type{<:NamedUnitRange}) = Mooncake.NoTangent
 
-@zero_derivative DefaultCtx Tuple{typeof(blockedperm), AbstractITensor, Any, Any}
-@zero_derivative DefaultCtx Tuple{typeof(blockedperm_nameddims), Any, Any, Any}
+@zero_derivative DefaultCtx Tuple{typeof(nameperm), Any, Any, Any}
 # `dimnames(::ITensor)` returns the stored names `Vector` directly, so its output
 # aliases a field, where `@zero_derivative` is documented to be incorrect. Let
 # Mooncake differentiate it through the underlying `getfield`, whose built-in rule

diff --git a/src/itensor.jl b/src/itensor.jl
@@ -1,16 +1,17 @@
-# TODO: Check `allunique(dimnames)`?
 struct ITensor{DimName} <: AbstractITensor{DimName}
     unnamed::AbstractArray
     dimnames::Vector{DimName}
+    function ITensor{DimName}(unnamed::AbstractArray, dimnames) where {DimName}
+        dimnames = collect(DimName, dimnames)
+        ndims(unnamed) == length(dimnames) ||
+            throw(ArgumentError("Number of named dims must match ndims."))
+        allunique(dimnames) ||
+            throw(ArgumentError("Dimension names must be distinct, got $(dimnames)."))
+        return new{DimName}(unnamed, dimnames)
+    end
 end
 
-# TODO: Check `allunique(dimnames)`?
-function ITensor(unnamed::AbstractArray, dims)
-    ndims(unnamed) == length(dims) ||
-        throw(ArgumentError("Number of named dims must match ndims."))
-    dimnames = collect(dims)
-    return ITensor{eltype(dimnames)}(unnamed, dimnames)
-end
+ITensor(unnamed::AbstractArray, dims) = ITensor{eltype(dims)}(unnamed, dims)
 ITensor(a::AbstractITensor, inds) = throw(ArgumentError("Already named."))
 ITensor(a::AbstractITensor) = ITensor(unnamed(a), dimnames(a))
 

diff --git a/src/tensoralgebra.jl b/src/tensoralgebra.jl
@@ -74,42 +74,23 @@ function mul!_nameddims(
     return a_dest
 end
 
-function TA.blockedperm(na::AbstractITensor, nameddim_blocks::Tuple...)
-    return blockedperm_nameddims(na, nameddim_blocks...)
-end
-function blockedperm_nameddims(a::AbstractITensor, nameddim_blocks::Tuple...)
-    dimname_blocks = map(group -> name.(group), nameddim_blocks)
-    dimnames_a = dimnames(a)
-    perms = map(dimname_blocks) do dimname_block
-        return TA.BaseExtensions.indexin(dimname_block, dimnames_a)
-    end
-    return TA.permmortar(perms)
+# Locate the named-dimension groups `group1`, `group2` within `a`, returning their two
+# positional index groups.
+function nameperm(a::AbstractITensor, group1, group2)
+    return TA.biperm(dimnames(a), name.(group1), name.(group2))
 end
 
 # i, j, k, l = named.((2, 2, 2, 2), ("i", "j", "k", "l"))
 # a = randn(i, j, k, l)
-# matricize(a, (i, k) => "a")
 # matricize(a, (i, k) => "a", (j, l) => "b")
-# TODO: Rewrite in terms of `matricize(a, .., (1, 3))` interface.
 function TA.matricize(a::AbstractITensor, fusions::Vararg{Pair, 2})
     return matricize_nameddims(a, fusions...)
 end
 function matricize_nameddims(na::AbstractITensor, fusions::Vararg{Pair, 2})
-    dimnames_fuse = map(group -> name.(group), first.(fusions))
-    dimnames_fused = last.(fusions)
-    if sum(length, dimnames_fuse) < ndims(na)
-        # Not all names are specified
-        dimnames_unspecified = dimnames_setdiff(dimnames(na), dimnames_fuse...)
-        dimnames_fuse = vcat(
-            tuple.(dimnames_unspecified), collect(dimnames_fuse)
-        )
-        dimnames_fused = vcat(
-            dimnames_unspecified, collect(dimnames_fused)
-        )
-    end
-    perm = TA.blockedperm(na, dimnames_fuse...)
-    a_fused = TA.matricize(unnamed(na), perm)
-    return nameddims(a_fused, dimnames_fused)
+    group1, group2 = first.(fusions)
+    perm_codomain, perm_domain = nameperm(na, group1, group2)
+    a_fused = TA.matricize(unnamed(na), perm_codomain, perm_domain)
+    return nameddims(a_fused, last.(fusions))
 end
 
 function TA.unmatricize(na::AbstractITensor, splitters::Vararg{Pair, 2})

diff --git a/test/Project.toml b/test/Project.toml
@@ -31,7 +31,7 @@ Adapt = "4"
 Aqua = "0.8.9"
 BlockArrays = "1"
 Combinatorics = "1"
-ITensorBase = "0.7"
+ITensorBase = "0.8"
 ITensorPkgSkeleton = "0.3.42"
 JLArrays = "0.2, 0.3"
 LinearAlgebra = "1.10"
@@ -41,7 +41,7 @@ Random = "1.10"
 SafeTestsets = "0.1"
 StableRNGs = "1"
 Suppressor = "0.2"
-TensorAlgebra = "0.10"
+TensorAlgebra = "0.11"
 TensorOperations = "5.3.1"
 TermInterface = "2"
 Test = "1.10"

diff --git a/test/test_mooncakeext.jl b/test/test_mooncakeext.jl
@@ -1,9 +1,8 @@
-using ITensorBase: ITensor, Name, NamedUnitRange, blockedperm_nameddims, dimnames,
-    dimnames_setdiff, inds, name, to_inds, uniquename
+using ITensorBase: ITensor, Name, NamedUnitRange, dimnames, dimnames_setdiff, inds, name,
+    nameperm, to_inds, uniquename
 using LinearAlgebra: mul!
 using Mooncake: Mooncake
 using Random: Random
-using TensorAlgebra: blockedperm
 using Test: @test, @testset
 
 @testset "MooncakeExt" begin
@@ -21,9 +20,8 @@ using Test: @test, @testset
         a1 = randn(elt, (2, 2))[i, j]
         a2 = randn(elt, (2, 2))[j, k]
 
-        Mooncake.TestUtils.test_rule(rng, blockedperm, a1, (i,), (j,); mode, is_primitive)
         Mooncake.TestUtils.test_rule(
-            rng, blockedperm_nameddims, a1, (i,), (j,); mode, is_primitive
+            rng, nameperm, a1, (i,), (j,); mode, is_primitive
         )
         Mooncake.TestUtils.test_rule(rng, dimnames, a1; mode, is_primitive)
         Mooncake.TestUtils.test_rule(rng, dimnames, a1, 1; mode, is_primitive)