Fix Folds.dict(array) (#51)

Author: tkf

src/collect.jl

@@ -56,15 +56,22 @@ function copy_default(T::Type{<:AbstractSet}, itr, ex)
     return Folds.reduce(union!!, itr |> Map(SingletonVector), ex; init = Empty(T))
 end
 
+struct Unpairs{Data}
+    data::Data
+end
+
+Base.pairs(pairs::Unpairs) = pairs.data
+
 function copy_default(T::Type{<:AbstractDict}, itr, ex)
     xf, array = extract_transducer(itr)
     if xf isa Union{Map{identity},IdentityTransducer}
         if array isa PartitionableArray
+            isempty(array) && return T(array)
             basesize =
                 something(get_basesize(ex), max(1, length(array) ÷ Threads.nthreads()))
             return Folds.reduce(
                 merge!!,
-                Iterators.partition(array, basesize),
+                Iterators.partition(array, basesize) |> Map(Unpairs),
                 set_basesize(ex, 1);
                 init = emptyshim(T),
             )

src/testing.jl

@@ -86,6 +86,7 @@ copy(Dict, (x => x^2 for x in Set(1:10)))                         # nodist,FIXME
 copy(Vector, 1:10)
 count(isodd(x) for x in 1:10)
 dict(x => x^2 for x in 1:10)
+dict([x => x^2 for x in 1:10])                                    # nodist,FIXME
 extrema((x - 5)^2 for x in 1:10)
 findall(isodd, 1:10)                                              # nodist,FIXME
 findfirst(x -> x > 3, 1:10)                                       # nodist,FIXME

test/test_reduce.jl

@@ -1,21 +1,28 @@
 module TestReduce
 
-# import Base as Folds  # should work (in Julia 1.7 and later)
 using Folds
 using Test
 
 @testset "findmin & findmax" begin
+    # Folds = Base  # should work (in Julia 1.7 and later)
     @test Folds.findmin('a':'z') == ('a', 1)
     @test Folds.findmax('a':'z') == ('z', 26)
     @test Folds.findmin(a -> 'z' - a, 'a':'z') == (0, 26)
     @test Folds.findmax(a -> 'z' - a, 'a':'z') == (25, 1)
 end
 
 @testset "argmin & argmax" begin
+    # Folds = Base  # should work (in Julia 1.7 and later)
     @test Folds.argmin('a':'z') == 1
     @test Folds.argmax('a':'z') == 26
     @test Folds.argmin(a -> 'z' - a, 'a':'z') == 'z'
     @test Folds.argmax(a -> 'z' - a, 'a':'z') == 'a'
 end
 
+@testset "dict" begin
+    @test Folds.dict(x => x^2 for x in 1:10) ==
+          Folds.dict([x => x^2 for x in 1:10]) ==
+          Dict(x => x^2 for x in 1:10)
+end
+
 end  # module