Add missing similar definition (#4)

Author: mtfishman

Project.toml

@@ -1,7 +1,7 @@
 name = "KroneckerArrays"
 uuid = "05d0b138-81bc-4ff7-84be-08becefb1ccc"
 authors = ["ITensor developers <[email protected]> and contributors"]
-version = "0.1.1"
+version = "0.1.2"
 
 [deps]
 DerivableInterfaces = "6c5e35bf-e59e-4898-b73c-732dcc4ba65f"

src/KroneckerArrays.jl

@@ -112,6 +112,11 @@ function Base.similar(
 ) where {A,B}
   return similar(A, map(ax -> ax.product.a, axs)) ⊗ similar(B, map(ax -> ax.product.b, axs))
 end
+function Base.similar(
+  ::Type{<:KroneckerArray{<:Any,<:Any,A,B}}, sz::Tuple{Int,Vararg{Int}}
+) where {A,B}
+  return similar(promote_type(A, B), sz)
+end
 
 Base.collect(a::KroneckerArray) = kron(a.a, a.b)
 

test/Project.toml

@@ -11,6 +11,7 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Aqua = "0.8"
 KroneckerArrays = "0.1"
 LinearAlgebra = "1.10"
+MatrixAlgebraKit = "0.2"
 SafeTestsets = "0.1"
 Suppressor = "0.2"
 Test = "1.10"

test/test_basics.jl

@@ -11,6 +11,8 @@ const elts = (Float32, Float64, ComplexF32, ComplexF64)
   a = randn(elt, 2, 2) ⊗ randn(elt, 3, 3)
   b = randn(elt, 2, 2) ⊗ randn(elt, 3, 3)
   c = a.a ⊗ b.b
+  @test similar(typeof(a), (2, 3)) isa Matrix{elt}
+  @test size(similar(typeof(a), (2, 3))) == (2, 3)
   @test a[1 × 1, 1 × 1] == a.a[1, 1] * a.b[1, 1]
   @test a[1 × 3, 2 × 1] == a.a[1, 2] * a.b[3, 1]
   @test a[1 × (2:3), 2 × 1] == a.a[1, 2] * a.b[2:3, 1]