From 8fad80887a6a5ae182c13eea13146f68544d0198 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Thu, 3 Apr 2025 15:41:19 -0400
Subject: [PATCH] Define zeros

---
 Project.toml             |  2 +-
 src/gradedarray.jl       |  6 ++++++
 test/test_gradedarray.jl | 21 ++++++++++++++++++---
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/Project.toml b/Project.toml
index 1c0e18b..56b1b8c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "GradedArrays"
 uuid = "bc96ca6e-b7c8-4bb6-888e-c93f838762c2"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.2.2"
+version = "0.2.3"
 
 [deps]
 BlockArrays = "8e7c35d0-a365-5155-bbbb-fb81a777f24e"
diff --git a/src/gradedarray.jl b/src/gradedarray.jl
index 7108b76..4d23d72 100644
--- a/src/gradedarray.jl
+++ b/src/gradedarray.jl
@@ -87,6 +87,12 @@ function Base.similar(
   return similar_blocksparse(a, elt, axes)
 end
 
+function Base.zeros(
+  elt::Type, ax::Tuple{AbstractGradedUnitRange,Vararg{AbstractGradedUnitRange}}
+)
+  return BlockSparseArray{elt}(undef, ax)
+end
+
 function getindex_blocksparse(a::AbstractArray, I::AbstractUnitRange...)
   a′ = similar(a, only.(axes.(I))...)
   a′ .= a
diff --git a/test/test_gradedarray.jl b/test/test_gradedarray.jl
index cab9301..233c386 100644
--- a/test/test_gradedarray.jl
+++ b/test/test_gradedarray.jl
@@ -57,9 +57,24 @@ const elts = (Float32, Float64, Complex{Float32}, Complex{Float64})
       @test 2 * Array(a) == b
     end
 
-    d1 = gradedrange([U1(0) => 2, U1(1) => 2])
-    d2 = gradedrange([U1(0) => 2, U1(1) => 2])
-    a = randn_blockdiagonal(elt, (d1, d2, d1, d2))
+    r = gradedrange([U1(0) => 2, U1(1) => 2])
+    a = zeros(r, r, r, r)
+    @test a isa BlockSparseArray{Float64}
+    @test eltype(a) === Float64
+    @test size(a) == (4, 4, 4, 4)
+    @test iszero(a)
+    @test iszero(blockstoredlength(a))
+
+    r = gradedrange([U1(0) => 2, U1(1) => 2])
+    a = zeros(elt, r, r, r, r)
+    @test a isa BlockSparseArray{elt}
+    @test eltype(a) === elt
+    @test size(a) == (4, 4, 4, 4)
+    @test iszero(a)
+    @test iszero(blockstoredlength(a))
+
+    r = gradedrange([U1(0) => 2, U1(1) => 2])
+    a = randn_blockdiagonal(elt, (r, r, r, r))
     b = similar(a, ComplexF64)
     @test b isa BlockSparseArray{ComplexF64}
     @test eltype(b) === ComplexF64