Move SparseArrays to an extension (#385)

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "BandedMatrices"
 uuid = "aae01518-5342-5314-be14-df237901396f"
-version = "0.17.32"
+version = "0.17.33"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
@@ -9,6 +9,12 @@ LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 
+[weakdeps]
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
+
+[extensions]
+BandedMatricesSparseArraysExt = "SparseArrays"
+
 [compat]
 Aqua = "0.6"
 ArrayLayouts = "1"
@@ -25,7 +31,8 @@ Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 GenericLinearAlgebra = "14197337-ba66-59df-a3e3-ca00e7dcff7a"
 InfiniteArrays = "4858937d-0d70-526a-a4dd-2d5cb5dd786c"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua", "Base64", "Documenter", "GenericLinearAlgebra", "InfiniteArrays", "Random", "Test"]
+test = ["Aqua", "Base64", "Documenter", "GenericLinearAlgebra", "InfiniteArrays", "Random", "SparseArrays", "Test"]

ext/BandedMatricesSparseArraysExt.jl

@@ -0,0 +1,38 @@
+module BandedMatricesSparseArraysExt
+
+using BandedMatrices
+using BandedMatrices: _banded_rowval, _banded_colval, _banded_nzval
+using SparseArrays
+import SparseArrays: sparse
+
+function sparse(B::BandedMatrix)
+	sparse(_banded_rowval(B), _banded_colval(B), _banded_nzval(B), size(B)...)
+end
+
+function BandedMatrices.bandwidths(A::SparseMatrixCSC)
+    l,u = -size(A,1),-size(A,2)
+
+    m,n = size(A)
+    rows = rowvals(A)
+    vals = nonzeros(A)
+    for j = 1:n
+        for ind in nzrange(A, j)
+            i = rows[ind]
+            # We skip non-structural zeros when computing the
+            # bandwidths.
+            iszero(vals[ind]) && continue
+            ij = abs(i-j)
+            if i ≥ j
+                l = max(l, ij)
+                u = max(u, -ij)
+            elseif i < j
+                l = max(l, -ij)
+                u = max(u, ij)
+            end
+        end
+    end
+
+    l,u
+end
+
+end

src/BandedMatrices.jl

@@ -1,5 +1,5 @@
 module BandedMatrices
-using Base, FillArrays, ArrayLayouts, LinearAlgebra, SparseArrays
+using Base, FillArrays, ArrayLayouts, LinearAlgebra
 
 using Base: require_one_based_indexing, reindex, checkbounds, @propagate_inbounds,
             oneto, promote_op, MultiplicativeInverses, OneTo, ReshapedArray, Slice
@@ -24,8 +24,6 @@ import LinearAlgebra: axpy!, _chol!, rot180, dot, cholcopy, _apply_ipiv_rows!,
 using LinearAlgebra.LAPACK
 using LinearAlgebra.LAPACK: chkuplo, chktrans
 
-import SparseArrays: sparse
-
 import ArrayLayouts: MemoryLayout, transposelayout, triangulardata,
                     conjlayout, symmetriclayout, symmetricdata,
                     triangularlayout, MatLdivVec, hermitianlayout, hermitiandata,
@@ -94,6 +92,11 @@ include("tribanded.jl")
 
 include("interfaceimpl.jl")
 
+if !isdefined(Base, :get_extension)
+    include("../ext/BandedMatricesSparseArraysExt.jl")
+end
+
 include("precompile.jl")
 
+
 end #module

src/banded/BandedMatrix.jl

@@ -782,9 +782,6 @@ function _banded_nzval(B::AbstractMatrix)
 end
 
 
-sparse(B::BandedMatrix) = sparse(_banded_rowval(B), _banded_colval(B), _banded_nzval(B), size(B)...)
-
-
 
 
 function _bidiagonalize!(A::AbstractMatrix{T}, M::BandedColumnMajor) where T

src/generic/AbstractBandedMatrix.jl

@@ -22,32 +22,6 @@ Returns a tuple containing the lower and upper bandwidth of `A`, in order.
 bandwidths(A::AbstractVecOrMat) = bandwidths(MemoryLayout(A), A)
 bandwidths(_, A) = (size(A,1)-1 , size(A,2)-1)
 
-function BandedMatrices.bandwidths(A::SparseMatrixCSC)
-    l,u = -size(A,1),-size(A,2)
-
-    m,n = size(A)
-    rows = rowvals(A)
-    vals = nonzeros(A)
-    for j = 1:n
-        for ind in nzrange(A, j)
-            i = rows[ind]
-            # We skip non-structural zeros when computing the
-            # bandwidths.
-            iszero(vals[ind]) && continue
-            ij = abs(i-j)
-            if i ≥ j
-                l = max(l, ij)
-                u = max(u, -ij)
-            elseif i < j
-                l = max(l, -ij)
-                u = max(u, ij)
-            end
-        end
-    end
-
-    l,u
-end
-
 """
     bandwidth(A,i)