From e38d0ef2f874fdd1eb6064b826cfc70f79a4c4dc Mon Sep 17 00:00:00 2001
From: Jishnu Bhattacharya <jishnub.github@gmail.com>
Date: Wed, 4 Oct 2023 00:46:09 +0530
Subject: [PATCH] replace ind2sub/sub2ind by CartesianIndices/LinearIndices

---
 src/sparsematrix.jl | 11 ++++++++---
 src/sparsevector.jl | 13 +++++++++----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/sparsematrix.jl b/src/sparsematrix.jl
index e2dfacce..be671e5b 100644
--- a/src/sparsematrix.jl
+++ b/src/sparsematrix.jl
@@ -3082,12 +3082,15 @@ function getindex(A::AbstractSparseMatrixCSC{Tv,Ti}, I::AbstractArray) where {Tv
     colptrB[colB] = 1
     idxB = 1
 
+    CartIndsA = CartesianIndices(szA)
+    CartIndsB = CartesianIndices(szB)
+
     for i in 1:n
         @boundscheck checkbounds(A, I[i])
-        row,col = Base._ind2sub(szA, I[i])
+        row,col = Tuple(CartIndsA[I[i]])
         for r in colptrA[col]:(colptrA[col+1]-1)
             @inbounds if rowvalA[r] == row
-                rowB,colB = Base._ind2sub(szB, i)
+                rowB,colB = Tuple(CartIndsB[i])
                 colptrB[colB+1] += 1
                 rowvalB[idxB] = rowB
                 nzvalB[idxB] = nzvalA[r]
@@ -3591,13 +3594,15 @@ function setindex!(A::AbstractSparseMatrixCSC, x::AbstractArray, Ix::AbstractVec
 
     isa(x, AbstractArray) && setindex_shape_check(x, length(I))
 
+    CartIndsA = CartesianIndices(szA)
+
     lastcol = 0
     (nrowA, ncolA) = szA
     @inbounds for xidx in 1:n
         sxidx = S[xidx]
         (sxidx < n) && (I[sxidx] == I[sxidx+1]) && continue
 
-        row,col = Base._ind2sub(szA, I[sxidx])
+        row,col = Tuple(CartIndsA[I[sxidx]])
         v = x[sxidx]
 
         if col > lastcol
diff --git a/src/sparsevector.jl b/src/sparsevector.jl
index fc555e69..73bd525b 100644
--- a/src/sparsevector.jl
+++ b/src/sparsevector.jl
@@ -779,9 +779,12 @@ function getindex(A::AbstractSparseMatrixCSC{Tv}, I::AbstractUnitRange) where Tv
     rowvalB = Vector{Int}(undef, nnzB)
     nzvalB = Vector{Tv}(undef, nnzB)
 
+    CartIndsA = CartesianIndices(szA)
+    LinIndsA = LinearIndices(szA)
+
     if nnzB > 0
-        rowstart,colstart = Base._ind2sub(szA, first(I))
-        rowend,colend = Base._ind2sub(szA, last(I))
+        rowstart,colstart = Tuple(CartIndsA[first(I)])
+        rowend,colend = Tuple(CartIndsA[last(I)])
 
         idxB = 1
         @inbounds for col in colstart:colend
@@ -790,7 +793,7 @@ function getindex(A::AbstractSparseMatrixCSC{Tv}, I::AbstractUnitRange) where Tv
             for r in colptrA[col]:(colptrA[col+1]-1)
                 rowA = rowvalA[r]
                 if minrow <= rowA <= maxrow
-                    rowvalB[idxB] = Base._sub2ind(szA, rowA, col) - first(I) + 1
+                    rowvalB[idxB] = LinIndsA[rowA, col] - first(I) + 1
                     nzvalB[idxB] = nzvalA[r]
                     idxB += 1
                 end
@@ -818,9 +821,11 @@ function getindex(A::AbstractSparseMatrixCSC{Tv,Ti}, I::AbstractVector) where {T
     rowvalB = Vector{Ti}(undef, nnzB)
     nzvalB = Vector{Tv}(undef, nnzB)
 
+    CartIndsA = CartesianIndices(szA)
+
     idxB = 1
     for i in 1:n
-        row,col = Base._ind2sub(szA, I[i])
+        row,col = Tuple(CartIndsA[I[i]])
         for r in colptrA[col]:(colptrA[col+1]-1)
             @inbounds if rowvalA[r] == row
                 if idxB <= nnzB