From a76bdf9b6dcd26c9e262a621b40efc1caf3c8f97 Mon Sep 17 00:00:00 2001
From: Christoph Finkensiep <chfin@chfin.de>
Date: Tue, 20 Mar 2018 22:45:56 +0100
Subject: [PATCH 1/4] implement iterator interface on plist

---
 src/PersistentList.jl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/PersistentList.jl b/src/PersistentList.jl
index 7558bb0..2a8d52d 100644
--- a/src/PersistentList.jl
+++ b/src/PersistentList.jl
@@ -49,6 +49,11 @@ Base.done(::AbstractList, ::EmptyList) = true
 Base.done(::AbstractList, ::PersistentList)      = false
 Base.next(::AbstractList, l::PersistentList) = (head(l), tail(l))
 
+Base.iteratorsize(::Type{AbstractList}) = Base.HasLength()
+Base.iteratoreltype(::Type{AbstractList}) = Base.HasEltype()
+Base.eltype(::Type{PersistentList{T}}) where T = T
+Base.eltype(::Type{EmptyList{T}}) where T = T
+
 Base.isequal(a::AbstractArray, l::PersistentList) = isequal(l, a)
 Base.isequal(l::PersistentList, a::AbstractArray) =
     isequal(length(l), length(a)) && all((el) -> el[1] == el[2], zipd(l, a))

From 2f8f414fc6bc95ff01063a917ddb76590b00613e Mon Sep 17 00:00:00 2001
From: Christoph Finkensiep <chfin@chfin.de>
Date: Tue, 20 Mar 2018 22:49:25 +0100
Subject: [PATCH 2/4] fix types for iterator methods

---
 src/PersistentList.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/PersistentList.jl b/src/PersistentList.jl
index 2a8d52d..7cb46b9 100644
--- a/src/PersistentList.jl
+++ b/src/PersistentList.jl
@@ -49,8 +49,8 @@ Base.done(::AbstractList, ::EmptyList) = true
 Base.done(::AbstractList, ::PersistentList)      = false
 Base.next(::AbstractList, l::PersistentList) = (head(l), tail(l))
 
-Base.iteratorsize(::Type{AbstractList}) = Base.HasLength()
-Base.iteratoreltype(::Type{AbstractList}) = Base.HasEltype()
+Base.iteratorsize(::Type{L}) where {L<:AbstractList} = Base.HasLength()
+Base.iteratoreltype(::Type{L}) where {L<:AbstracList} = Base.HasEltype()
 Base.eltype(::Type{PersistentList{T}}) where T = T
 Base.eltype(::Type{EmptyList{T}}) where T = T
 

From 6c805a417c2124cab03b5e023eab4a132bef376f Mon Sep 17 00:00:00 2001
From: Christoph Finkensiep <chfin@chfin.de>
Date: Tue, 20 Mar 2018 23:00:01 +0100
Subject: [PATCH 3/4] add tests for plist iterator interface

---
 src/PersistentList.jl      |  2 +-
 test/PersistentListTest.jl | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/PersistentList.jl b/src/PersistentList.jl
index 7cb46b9..887df5e 100644
--- a/src/PersistentList.jl
+++ b/src/PersistentList.jl
@@ -50,7 +50,7 @@ Base.done(::AbstractList, ::PersistentList)      = false
 Base.next(::AbstractList, l::PersistentList) = (head(l), tail(l))
 
 Base.iteratorsize(::Type{L}) where {L<:AbstractList} = Base.HasLength()
-Base.iteratoreltype(::Type{L}) where {L<:AbstracList} = Base.HasEltype()
+Base.iteratoreltype(::Type{L}) where {L<:AbstractList} = Base.HasEltype()
 Base.eltype(::Type{PersistentList{T}}) where T = T
 Base.eltype(::Type{EmptyList{T}}) where T = T
 
diff --git a/test/PersistentListTest.jl b/test/PersistentListTest.jl
index dc99a83..c5bcbb5 100644
--- a/test/PersistentListTest.jl
+++ b/test/PersistentListTest.jl
@@ -63,4 +63,14 @@ using Base.Test
         @test !isempty(PersistentList([1]))
     end
 
+    @testset "iterator interface" begin
+        T1 = typeof(plist([1,2,3]))
+        T2 = typeof(plist(Int[]))
+        @test Base.iteratorsize(T1) == Base.HasLength()
+        @test Base.iteratorsize(T2) == Base.HasLength()
+        @test Base.iteratoreltype(T1) == Base.HasEltype()
+        @test Base.iteratoreltype(T2) == Base.HasEltype()
+        @test Base.eltype(T1) == Int
+        @test Base.eltype(T2) == Int
+    end
 end

From 1012d7983ef65b2c4778d152c4f4e49be950859e Mon Sep 17 00:00:00 2001
From: Christoph Finkensiep <chfin@chfin.de>
Date: Tue, 20 Mar 2018 23:08:13 +0100
Subject: [PATCH 4/4] more tests for plist eltype (including collect)

---
 test/PersistentListTest.jl | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/test/PersistentListTest.jl b/test/PersistentListTest.jl
index c5bcbb5..572142c 100644
--- a/test/PersistentListTest.jl
+++ b/test/PersistentListTest.jl
@@ -64,13 +64,19 @@ using Base.Test
     end
 
     @testset "iterator interface" begin
-        T1 = typeof(plist([1,2,3]))
-        T2 = typeof(plist(Int[]))
+        l1 = plist([1,2,3])
+        l2 = plist(Int[])
+        T1 = typeof(l1)
+        T2 = typeof(l2)
+
         @test Base.iteratorsize(T1) == Base.HasLength()
         @test Base.iteratorsize(T2) == Base.HasLength()
         @test Base.iteratoreltype(T1) == Base.HasEltype()
         @test Base.iteratoreltype(T2) == Base.HasEltype()
         @test Base.eltype(T1) == Int
         @test Base.eltype(T2) == Int
+
+        @test Base.eltype(typeof(collect(l1))) == Int
+        @test Base.eltype(typeof(collect(l2))) == Int
     end
 end