Refactor not_iterator_of_pairs to stop using InteractiveUtils

Project.toml

@@ -3,7 +3,6 @@ uuid = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 version = "0.19.0-DEV"
 
 [deps]
-InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 OrderedCollections = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
 
 [compat]

src/dict_support.jl

@@ -1,9 +1,16 @@
 # support functions
 
-using InteractiveUtils: methodswith
-
-function not_iterator_of_pairs(kv)
-    return any(x->isempty(methodswith(typeof(kv), x, true)),
-               [iterate]) ||
-           any(x->!isa(x, Union{Tuple,Pair}), kv)
+function not_iterator_of_pairs(kv::T) where T
+    # if the object is not iterable, return true, else check the eltype of the iteration
+    Base.isiterable(T) && return true 
+    # else, check if we can check `eltype`:
+    if Base.IteratorEltype(kv) isa Base.HasEltype
+        typ = eltype(kv)
+        if !(typ == Any)
+            return !(typ <: Union{<: Tuple, <: Pair})
+        end
+    end
+    # we can't check eltype, or eltype is not useful, 
+    # so brute force it.
+    return any(x->!isa(x, Union{Tuple,Pair}), kv)
 end

test/test_priority_queue.jl

@@ -105,6 +105,40 @@ import Base.Order.Reverse
             @test_throws ArgumentError PriorityQueue(Reverse, Reverse)
         end
 
+        @testset "Strange eltype situations" begin
+            @testset "Eltype unknown" begin
+                struct EltypeUnknownIterator{T}
+                    x::T
+                end
+                Base.IteratorEltype(::EltypeUnknownIterator) = Base.EltypeUnknown()
+                Base.iterate(i::EltypeUnknownIterator) = Base.iterate(i.x)
+                Base.iterate(i::EltypeUnknownIterator, state) = Base.iterate(i.x, state)
+                Base.IteratorSize(i::EltypeUnknownIterator) = Base.IteratorSize(i.x)
+                Base.length(i::EltypeUnknownIterator) = Base.length(i.x)
+                Base.size(i::EltypeUnknownIterator) = Base.size(i.x)
+
+                @test_nowarn PriorityQueue(Dict(zip(1:5, 2:6)))
+                @test_nowarn PriorityQueue(EltypeUnknownIterator(Dict(zip(1:5, 2:6))))
+                @test_throws ArgumentError PriorityQueue(EltypeUnknownIterator(['a']))
+            end
+
+            @testset "Eltype any" begin
+                struct EltypeAnyIterator{T}
+                    x::T
+                end
+                Base.IteratorEltype(::EltypeAnyIterator) = Base.HasEltype()
+                Base.eltype(::EltypeAnyIterator) = Any
+                Base.iterate(i::EltypeAnyIterator) = Base.iterate(i.x)
+                Base.iterate(i::EltypeAnyIterator, state) = Base.iterate(i.x, state)
+                Base.IteratorSize(i::EltypeAnyIterator) = Base.IteratorSize(i.x)
+                Base.length(i::EltypeAnyIterator) = Base.length(i.x)
+                Base.size(i::EltypeAnyIterator) = Base.size(i.x)
+
+                @test_nowarn PriorityQueue(EltypeAnyIterator(Dict(zip(1:5, 2:6))))
+                @test_throws ArgumentError PriorityQueue(EltypeAnyIterator(['a']))
+            end
+        end
+
     end
 
     @testset "PriorityQueueMethods" begin