Initial commit

Author: raphasampaio

src/sparse_array.jl

@@ -38,6 +38,13 @@ SparseArray{T}(dims::NTuple{N, Int}, default_value::T = zero(T)) where {T, N} =
 SparseArray{T}(dims::Vararg{Int, N}) where {T, N} =
     SparseArray{T, N}(dims, zero(T))
 
+# Array-like constructor: SparseArray{T, N}(undef, dims...)
+SparseArray{T, N}(::UndefInitializer, dims::Vararg{Int, N}) where {T, N} =
+    SparseArray{T, N}(dims, zero(T))
+
+SparseArray{T, N}(::UndefInitializer, dims::NTuple{N, Int}) where {T, N} =
+    SparseArray{T, N}(dims, zero(T))
+
 # Constructor from dense array
 function SparseArray(A::AbstractArray{T, N}) where {T, N}
     sparse_array = SparseArray{T, N}(size(A))

test/test_construction.jl

@@ -36,6 +36,18 @@ using Test
     @test E[3, 1] == 2
     @test E[3, 3] == 4
     @test nnz(E) == 4  # Only non-zero elements stored
+    
+    # Array-like constructor with undef
+    F = SparseArray{Float64, 2}(undef, 2, 3)
+    @test size(F) == (2, 3)
+    @test eltype(F) == Float64
+    @test nnz(F) == 0
+    @test F.default_value == 0.0
+    
+    G = SparseArray{Int, 3}(undef, (2, 2, 2))
+    @test size(G) == (2, 2, 2)
+    @test eltype(G) == Int
+    @test nnz(G) == 0
 end
 
 end