Faster A[Block(1,2)] for BandedBlockBandedMatrix (#166)

* Faster A[Block(1,2)] for BandedBlockBandedMatrix

* Update ci.yml

* Better show

Author: dlfivefifty

.github/workflows/ci.yml

@@ -22,7 +22,6 @@ jobs:
         version:
           - '1.6'
           - '1'
-          - '~1.10.0-0'
         os:
           - ubuntu-latest
           - macOS-latest

Project.toml

@@ -1,6 +1,6 @@
 name = "BlockBandedMatrices"
 uuid = "ffab5731-97b5-5995-9138-79e8c1846df0"
-version = "0.12.4"
+version = "0.12.5"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/BandedBlockBandedMatrix.jl

@@ -465,14 +465,6 @@ const BandedBlockBandedBlock{T, BLOCKS, RAXIS} = SubArray{T,2,BandedBlockBandedM
 BroadcastStyle(::Type{<: BandedBlockBandedBlock}) = BandedStyle()
 
 
-function inblockbands(V::SubArray{<:Any,2,<:AbstractMatrix,<:Tuple{BlockSlice1,BlockSlice1},false})
-    A = parent(V)
-    K_sl, J_sl = parentindices(V)
-    K, J = K_sl.block, J_sl.block
-    l,u = blockbandwidths(A)
-    -l ≤ Int(J-K) ≤ u
-end
-
 function parentblock(V::SubArray{T,2,<:AbstractMatrix,<:Tuple{BlockSlice{<:BlockIndexRange1},BlockSlice{<:BlockIndexRange1}}}) where T
     A = parent(V)
     K_sl, J_sl = parentindices(V)
@@ -499,6 +491,29 @@ parentblocks2Int(V::BandedBlockBandedBlock)::Tuple{Int,Int} = Int(first(parentin
 ######################################
 # BandedMatrix interface  for Blocks #
 ######################################
+getindex(A::BandedBlockBandedMatrix, KJ::Block{2}) = A[Block.(KJ.n)...]
+
+function inblockbands(A, K::Block{1}, J::Block{1})
+    l,u = blockbandwidths(A)
+    -l ≤ Int(J-K) ≤ u
+end
+
+function inblockbands(V::SubArray{<:Any,2,<:AbstractMatrix,<:Tuple{BlockSlice1,BlockSlice1},false})
+    K_sl, J_sl = parentindices(V)
+    inblockbands(parent(V), K_sl.block, J_sl.block)
+end
+
+function getindex(A::BandedBlockBandedMatrix{T}, K::Block{1}, J::Block{1}) where T
+    inblockbands(A, K, J) || return BandedMatrix{T}(undef, (length(axes(A,1)[K]), length(axes(A,2)[J])), (-720,-720))
+    _BandedMatrix(A.data[A.u + K - J + 1, J], length(axes(A,1)[K]), subblockbandwidths(A)...)
+end
+
+function getindex(A::BandedBlockBandedMatrix{T}, KR::BlockRange{1}, JR::BlockRange{1}) where T
+    sh = Int(KR[1]-JR[1])
+    l,u = blockbandwidths(A)
+    _BandedBlockBandedMatrix(A.data[:,JR], axes(axes(A,1)[KR],1), (l-sh, u+sh), subblockbandwidths(A))
+end
+
 @inline function bandwidths(V::SubArray{T,2,<:AbstractMatrix,<:Tuple{BlockSlice1,BlockSlice1}}) where T
     inblockbands(V) && return subblockbandwidths(parent(V))
     (-720,-720)
@@ -598,3 +613,16 @@ lmul!(x::Number, A::BandedBlockBandedMatrix) = (lmul!(x, A.data); A)
 rmul!(A::BandedBlockBandedMatrix, x::Number) = (rmul!(A.data, x); A)
 *(x::Number, A::BandedBlockBandedMatrix) = _BandedBlockBandedMatrix(x*A.data, axes(A,1), blockbandwidths(A), subblockbandwidths(A))
 *(A::BandedBlockBandedMatrix, x::Number) = _BandedBlockBandedMatrix(A.data*x, axes(A,1), blockbandwidths(A), subblockbandwidths(A))
+
+
+#####
+# summary
+#####
+
+_bandedblockbanded_summary(io, B::BandedBlockBandedMatrix{T}) where T = print(io, "BandedBlockBandedMatrix{$T} with block-bandwidths $(blockbandwidths(B)) and sub-block-bandwidths block-bandwidths $(subblockbandwidths(B))")
+BlockArrays._show_typeof(io::IO, B::DefaultBandedBlockBandedMatrix) = _bandedblockbanded_summary(io, B)
+function BlockArrays._show_typeof(io::IO, B::BandedBlockBandedMatrix)
+    _bandedblockbanded_summary(io, B)
+    print(io, " with data ")
+    summary(io, B.data)
+end