fix eltype for partition iterators of substrings (#51773)

Fixes #51771 The convert method that asserts in #51771 is arguably still faulty though. (cherry picked from commit cf00550)
JuliaLang · Oct 24, 2023 · 4e1759c · 4e1759c
1 parent 7ae1535
commit 4e1759c
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 0 deletions.
diff --git a/base/strings/util.jl b/base/strings/util.jl
@@ -571,6 +571,8 @@ end
 
 # Specialization for partition(s,n) to return a SubString
 eltype(::Type{PartitionIterator{T}}) where {T<:AbstractString} = SubString{T}
+# SubStrings do not nest
+eltype(::Type{PartitionIterator{T}}) where {T<:SubString} = T
 
 function iterate(itr::PartitionIterator{<:AbstractString}, state = firstindex(itr.c))
     state > ncodeunits(itr.c) && return nothing

diff --git a/test/iterators.jl b/test/iterators.jl
@@ -1001,3 +1001,7 @@ end
     end
     @test v == ()
 end
+
+@testset "collect partition substring" begin
+    @test collect(Iterators.partition(lstrip("01111", '0'), 2)) == ["11", "11"]
+end