support pretty printing with BlockArray when blocks are sparse (#234)

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BlockArrays"
 uuid = "8e7c35d0-a365-5155-bbbb-fb81a777f24e"
-version = "0.16.22"
+version = "0.16.23"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/blockarray.jl

@@ -426,8 +426,13 @@ function _replace_in_print_matrix_inds(block_arr, i...)
 end
 function Base.replace_in_print_matrix(block_arr::BlockArray{<:Any,2}, i::Integer, j::Integer, s::AbstractString)
     try
-        bl, inds = _replace_in_print_matrix_inds(block_arr, i, j)
-        Base.replace_in_print_matrix(bl, inds..., s)
+        I,J = findblock(axes(block_arr,1),i),findblock(axes(block_arr,2),j)
+        if Int(I) in colsupport(block_arr.blocks, Int(J))
+            bl, inds = _replace_in_print_matrix_inds(block_arr, i, j)
+            Base.replace_in_print_matrix(bl, inds..., s)
+        else
+            Base.replace_with_centered_mark(s)
+        end
     catch UndefRefError # thrown with undef_blocks
         s
     end

test/test_blockarrayinterface.jl

@@ -126,6 +126,7 @@ end
     @test_throws BlockBoundsError A[Block(1, 3)]
     @test A == [1 2 0 0; 0 0 1 2]
     @test BlockArray(A) == A
+    @test stringmime("text/plain", A) == "2×2-blocked 2×4 BlockMatrix{$Int, Diagonal{Matrix{$Int}, Vector{Matrix{$Int}}}, Tuple{BlockedUnitRange{Vector{$Int}}, BlockedUnitRange{Vector{$Int}}}}:\n 1  2  │  ⋅  ⋅\n ──────┼──────\n ⋅  ⋅  │  1  2"
 
     N = 3
     D = Diagonal(mortar(Fill.(-(0:N) - (0:N) .^ 2, 1:2:2N+1)))