error message for indexing with BitArray (#38689)

* error message for indexing with BitArray

* modify show_index instead

* use BitMatrix in error message

* update error msg

* BitVector !?

Author: JeffFessler

base/errorshow.jl

@@ -31,7 +31,7 @@ showerror(io::IO, ex) = show(io, ex)
 
 show_index(io::IO, x::Any) = show(io, x)
 show_index(io::IO, x::Slice) = show_index(io, x.indices)
-show_index(io::IO, x::LogicalIndex) = show_index(io, x.mask)
+show_index(io::IO, x::LogicalIndex) = summary(io, x.mask)
 show_index(io::IO, x::OneTo) = print(io, "1:", x.stop)
 show_index(io::IO, x::Colon) = print(io, ':')
 

test/arrayops.jl

@@ -2842,7 +2842,7 @@ end
     b = IOBuffer()
     showerror(b, err)
     @test String(take!(b)) ==
-        "BoundsError: attempt to access 2×2 Matrix{Float64} at index [10, Bool[1, 1]]"
+        "BoundsError: attempt to access 2×2 Matrix{Float64} at index [10, 2-element BitVector]"
 
     # Also test : directly for custom types for which it may appear as-is
     err = BoundsError(x, (10, :))

test/errorshow.jl

@@ -297,6 +297,8 @@ let undefvar
     @test err_str == "BoundsError: attempt to access 3-element Vector{$Int} at index [-2, 1]"
     err_str = @except_str [5, 4, 3][1:5] BoundsError
     @test err_str == "BoundsError: attempt to access 3-element Vector{$Int} at index [1:5]"
+    err_str = @except_str [5, 4, 3][trues(6,7)] BoundsError
+    @test err_str == "BoundsError: attempt to access 3-element Vector{$Int} at index [6×7 BitMatrix]"
 
     err_str = @except_str Bounded(2)[3] BoundsError
     @test err_str == "BoundsError: attempt to access 2-size Bounded at index [3]"