From 5331823ac10e13500212afbc57757a29261d6bc4 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Sun, 2 Feb 2025 10:55:41 -0500
Subject: [PATCH 1/5] Change onehot to oneelement

---
 Project.toml           |  2 +-
 src/abstractitensor.jl | 18 ++++++++++++++++++
 src/quirks.jl          | 25 ++++++++++++-------------
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/Project.toml b/Project.toml
index b1326a1..feab04f 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "ITensorBase"
 uuid = "4795dd04-0d67-49bb-8f44-b89c448a1dc7"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.1.13"
+version = "0.1.14"
 
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
diff --git a/src/abstractitensor.jl b/src/abstractitensor.jl
index e6a825f..c2eac47 100644
--- a/src/abstractitensor.jl
+++ b/src/abstractitensor.jl
@@ -91,6 +91,24 @@ function ITensor(parent::AbstractArray)
   return ITensor(parent, ())
 end
 
+# TODO:
+# 1. Generalize this to arbitrary dimensions.
+# 2. Define a basic non-ITensor version in `SparseArraysBase.jl`,
+#    and this constructor can wrap that one. It could construct
+#    a `OneElement` sparse object like `FillArrays.OneElement`
+#    (https://juliaarrays.github.io/FillArrays.jl/stable/#FillArrays.OneElement).
+# 3. Define `oneelement(value, index::Tuple{Vargarg{Int}}, axes::Tuple{Vararg{Index}})`,
+#    where the pair version calls out to that one.
+function oneelement(elt::Type{<:Number}, iv::Pair{<:Index,<:Int})
+  a = ITensor(first(iv))
+  a[last(iv)] = one(elt)
+  return a
+end
+# TODO: The non-ITensor version should default to `Float64`,
+# like `FillArrays.OneElement`.
+# TODO: Make the element type `UnspecifiedOne`.
+oneelement(iv::Pair{<:Index,<:Int}) = oneelement(Bool, iv)
+
 using Accessors: @set
 setdenamed(a::ITensor, denamed) = (@set a.parent = denamed)
 setdenamed!(a::ITensor, denamed) = (a.parent = denamed)
diff --git a/src/quirks.jl b/src/quirks.jl
index 7cd48e5..e290280 100644
--- a/src/quirks.jl
+++ b/src/quirks.jl
@@ -1,32 +1,31 @@
 # TODO: Define this properly.
+# TODO: Rename this to `dual`.
 dag(i::Index) = i
 # TODO: Define this properly.
+# TODO: Rename this to `dual`.
 dag(a::ITensor) = a
-# TODO: Deprecate.
+
+# TODO: Deprecate, just use `Int(length(i))` or
+# `unname(length(i))` directly.
 # Conversion to `Int` is used in case the output is named.
 dim(i::Index) = Int(length(i))
 # TODO: Deprecate.
 # Conversion to `Int` is used in case the output is named.
+# TODO: Deprecate, just use `Int(length(i))` or
+# `unname(length(i))` directly.
 dim(a::AbstractITensor) = Int(length(a))
+
 # TODO: Define this properly.
-hasqns(i::Index) = false
+# TODO: Maybe rename to `isgraded(i::Index) = isgraded(dename(i))`.
+hasqns(::Index) = false
 # TODO: Define this properly.
-hasqns(i::AbstractITensor) = false
+# TODO: Maybe rename to `isgraded(a) = all(isgraded, axes(a))`.
+hasqns(::AbstractITensor) = false
 
 # This seems to be needed to get broadcasting working.
 # TODO: Investigate this and see if we can get rid of it.
 Base.Broadcast.extrude(a::AbstractITensor) = a
 
-# TODO: Generalize this.
-# Maybe define it as `oneelement`, and base it on
-# `FillArrays.OneElement` (https://juliaarrays.github.io/FillArrays.jl/stable/#FillArrays.OneElement).
-function onehot(elt::Type{<:Number}, iv::Pair{<:Index,<:Int})
-  a = ITensor(first(iv))
-  a[last(iv)] = one(elt)
-  return a
-end
-onehot(iv::Pair{<:Index,<:Int}) = onehot(Bool, iv)
-
 # TODO: This is just a stand-in for truncated SVD
 # that only makes use of `maxdim`, just to get some
 # functionality running in `ITensorMPS.jl`.

From 5576de16c9e8dc9ed6f3d5fec0196aa477a71c51 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Sun, 2 Feb 2025 10:59:11 -0500
Subject: [PATCH 2/5] Add tests

---
 test/test_basics.jl | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/test/test_basics.jl b/test/test_basics.jl
index c2c0e1b..fd3c214 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -1,5 +1,16 @@
 using ITensorBase:
-  ITensorBase, ITensor, Index, gettag, hastag, inds, plev, prime, settag, tags, unsettag
+  ITensorBase,
+  ITensor,
+  Index,
+  gettag,
+  hastag,
+  inds,
+  oneelement,
+  plev,
+  prime,
+  settag,
+  tags,
+  unsettag
 using DiagonalArrays: δ, delta, diagview
 using NamedDimsArrays: dename, name, named
 using Test: @test, @test_broken, @testset
@@ -35,6 +46,27 @@ using Test: @test, @test_broken, @testset
     @test plev(i) == 0
     @test length(tags(i)) == 0
   end
+  @testset "oneelement" begin
+    i = Index(3)
+    a = oneelement(i => 2)
+    @test a isa ITensor
+    @test ndims(a) == 1
+    @test issetequal(inds(a), (i,))
+    @test eltype(a) === Bool
+    @test a[1] == 0
+    @test a[2] == 1
+    @test a[3] == 0
+
+    i = Index(3)
+    a = oneelement(Float32, i => 2)
+    @test a isa ITensor
+    @test ndims(a) == 1
+    @test issetequal(inds(a), (i,))
+    @test eltype(a) === Float32
+    @test a[1] == 0
+    @test a[2] == 1
+    @test a[3] == 0
+  end
   @testset "delta" begin
     i, j = Index.((2, 2))
     for a in (

From baf0d2f464c3869d6e7c4c008051d17cdbae525c Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Sun, 2 Feb 2025 21:48:27 -0500
Subject: [PATCH 3/5] Implement `oneelement` in SparseArraysBaseExt

---
 Project.toml                                  |  3 ++
 .../ITensorBaseSparseArraysBaseExt.jl         | 13 +++++++
 src/abstractitensor.jl                        | 18 ---------
 test/Project.toml                             |  1 +
 test/test_basics.jl                           | 38 +++++++++----------
 5 files changed, 36 insertions(+), 37 deletions(-)
 create mode 100644 ext/ITensorBaseSparseArraysBaseExt/ITensorBaseSparseArraysBaseExt.jl

diff --git a/Project.toml b/Project.toml
index feab04f..c6e2c31 100644
--- a/Project.toml
+++ b/Project.toml
@@ -16,9 +16,11 @@ VectorInterface = "409d34a3-91d5-4945-b6ec-7529ddf182d8"
 
 [weakdeps]
 DiagonalArrays = "74fd4be6-21e2-4f6f-823a-4360d37c7a77"
+SparseArraysBase = "0d5efcca-f356-4864-8770-e1ed8d78f208"
 
 [extensions]
 ITensorBaseDiagonalArraysExt = "DiagonalArrays"
+ITensorBaseSparseArraysBaseExt = ["NamedDimsArrays", "SparseArraysBase"]
 
 [compat]
 Accessors = "0.1.39"
@@ -28,6 +30,7 @@ FillArrays = "1.13.0"
 LinearAlgebra = "1.10"
 MapBroadcast = "0.1.5"
 NamedDimsArrays = "0.4"
+SparseArraysBase = "0.2.10"
 UnallocatedArrays = "0.1.1"
 UnspecifiedTypes = "0.1.1"
 VectorInterface = "0.5.0"
diff --git a/ext/ITensorBaseSparseArraysBaseExt/ITensorBaseSparseArraysBaseExt.jl b/ext/ITensorBaseSparseArraysBaseExt/ITensorBaseSparseArraysBaseExt.jl
new file mode 100644
index 0000000..e8eb709
--- /dev/null
+++ b/ext/ITensorBaseSparseArraysBaseExt/ITensorBaseSparseArraysBaseExt.jl
@@ -0,0 +1,13 @@
+module ITensorBaseSparseArraysBaseExt
+
+using ITensorBase: ITensor, Index
+using NamedDimsArrays: dename
+using SparseArraysBase: SparseArraysBase, oneelement
+
+function SparseArraysBase.oneelement(
+  value, index::NTuple{N,Int}, ax::NTuple{N,Index}
+) where {N}
+  return ITensor(oneelement(value, index, only.(axes.(dename.(ax)))), ax)
+end
+
+end
diff --git a/src/abstractitensor.jl b/src/abstractitensor.jl
index c2eac47..e6a825f 100644
--- a/src/abstractitensor.jl
+++ b/src/abstractitensor.jl
@@ -91,24 +91,6 @@ function ITensor(parent::AbstractArray)
   return ITensor(parent, ())
 end
 
-# TODO:
-# 1. Generalize this to arbitrary dimensions.
-# 2. Define a basic non-ITensor version in `SparseArraysBase.jl`,
-#    and this constructor can wrap that one. It could construct
-#    a `OneElement` sparse object like `FillArrays.OneElement`
-#    (https://juliaarrays.github.io/FillArrays.jl/stable/#FillArrays.OneElement).
-# 3. Define `oneelement(value, index::Tuple{Vargarg{Int}}, axes::Tuple{Vararg{Index}})`,
-#    where the pair version calls out to that one.
-function oneelement(elt::Type{<:Number}, iv::Pair{<:Index,<:Int})
-  a = ITensor(first(iv))
-  a[last(iv)] = one(elt)
-  return a
-end
-# TODO: The non-ITensor version should default to `Float64`,
-# like `FillArrays.OneElement`.
-# TODO: Make the element type `UnspecifiedOne`.
-oneelement(iv::Pair{<:Index,<:Int}) = oneelement(Bool, iv)
-
 using Accessors: @set
 setdenamed(a::ITensor, denamed) = (@set a.parent = denamed)
 setdenamed!(a::ITensor, denamed) = (a.parent = denamed)
diff --git a/test/Project.toml b/test/Project.toml
index 355bb50..fce2cd3 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -5,6 +5,7 @@ ITensorBase = "4795dd04-0d67-49bb-8f44-b89c448a1dc7"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 NamedDimsArrays = "60cbd0c0-df58-4cb7-918c-6f5607b73fde"
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+SparseArraysBase = "0d5efcca-f356-4864-8770-e1ed8d78f208"
 Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
diff --git a/test/test_basics.jl b/test/test_basics.jl
index fd3c214..1683a47 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -5,7 +5,6 @@ using ITensorBase:
   gettag,
   hastag,
   inds,
-  oneelement,
   plev,
   prime,
   settag,
@@ -13,6 +12,7 @@ using ITensorBase:
   unsettag
 using DiagonalArrays: δ, delta, diagview
 using NamedDimsArrays: dename, name, named
+using SparseArraysBase: oneelement
 using Test: @test, @test_broken, @testset
 
 @testset "ITensorBase" begin
@@ -46,6 +46,24 @@ using Test: @test, @test_broken, @testset
     @test plev(i) == 0
     @test length(tags(i)) == 0
   end
+  @testset "delta" begin
+    i, j = Index.((2, 2))
+    for a in (
+      delta(i, j),
+      delta(Bool, i, j),
+      delta((i, j)),
+      delta(Bool, (i, j)),
+      δ(i, j),
+      δ(Bool, i, j),
+      δ((i, j)),
+      δ(Bool, (i, j)),
+    )
+      @test eltype(a) === Bool
+      # TODO: Fix this.
+      @test_broken diagview(a)
+      @test diagview(dename(a)) == ones(2)
+    end
+  end
   @testset "oneelement" begin
     i = Index(3)
     a = oneelement(i => 2)
@@ -67,22 +85,4 @@ using Test: @test, @test_broken, @testset
     @test a[2] == 1
     @test a[3] == 0
   end
-  @testset "delta" begin
-    i, j = Index.((2, 2))
-    for a in (
-      delta(i, j),
-      delta(Bool, i, j),
-      delta((i, j)),
-      delta(Bool, (i, j)),
-      δ(i, j),
-      δ(Bool, i, j),
-      δ((i, j)),
-      δ(Bool, (i, j)),
-    )
-      @test eltype(a) === Bool
-      # TODO: Fix this.
-      @test_broken diagview(a)
-      @test diagview(dename(a)) == ones(2)
-    end
-  end
 end

From 387bb9eb5c362355ca79ad51be22162c2a0d2805 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Sun, 2 Feb 2025 21:53:15 -0500
Subject: [PATCH 4/5] Bump requires SparseArraysBase version

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index c6e2c31..028d514 100644
--- a/Project.toml
+++ b/Project.toml
@@ -30,7 +30,7 @@ FillArrays = "1.13.0"
 LinearAlgebra = "1.10"
 MapBroadcast = "0.1.5"
 NamedDimsArrays = "0.4"
-SparseArraysBase = "0.2.10"
+SparseArraysBase = "0.2.11"
 UnallocatedArrays = "0.1.1"
 UnspecifiedTypes = "0.1.1"
 VectorInterface = "0.5.0"

From 917cf559cf4aaaed9c9e950aee4c3af9e650f80f Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Sun, 2 Feb 2025 21:57:19 -0500
Subject: [PATCH 5/5] Format

---
 test/test_basics.jl | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/test/test_basics.jl b/test/test_basics.jl
index 1683a47..b19c892 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -1,15 +1,5 @@
 using ITensorBase:
-  ITensorBase,
-  ITensor,
-  Index,
-  gettag,
-  hastag,
-  inds,
-  plev,
-  prime,
-  settag,
-  tags,
-  unsettag
+  ITensorBase, ITensor, Index, gettag, hastag, inds, plev, prime, settag, tags, unsettag
 using DiagonalArrays: δ, delta, diagview
 using NamedDimsArrays: dename, name, named
 using SparseArraysBase: oneelement