Bugfix type instability in length(::Arrow.ToList) (#497)

Co-authored-by: Ben Baumgold <[email protected]>

Author: JoaoAparicio

Project.toml

@@ -17,7 +17,7 @@
 name = "Arrow"
 uuid = "69666777-d1a9-59fb-9406-91d4454c9d45"
 authors = ["quinnj <[email protected]>"]
-version = "2.7.0"
+version = "2.7.1"
 
 [deps]
 ArrowTypes = "31f734f8-188a-4ce0-8406-c8a06bd891cd"

src/arraytypes/list.jl

@@ -130,7 +130,7 @@ function ToList(input; largelists::Bool=false)
 end
 
 Base.IndexStyle(::Type{<:ToList}) = Base.IndexLinear()
-Base.size(x::ToList) = (length(x.inds) == 0 ? 0 : x.inds[end],)
+Base.size(x::ToList{T,S,A,I}) where {T,S,A,I} = (isempty(x.inds) ? zero(I) : x.inds[end],)
 
 function Base.pointer(A::ToList{UInt8}, i::Integer)
     chunk = searchsortedfirst(A.inds, i)