Fix symdiff/symdiff! for vector inputs with duplicates, closes #34686 (…

…#46397)
JuliaLang · Sep 14, 2022 · c6abccf · c6abccf
1 parent 2cfcc1a
commit c6abccf
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Showing 4 changed files with 15 additions and 11 deletions.
diff --git a/base/abstractset.jl b/base/abstractset.jl
@@ -248,7 +248,6 @@ end
 
 Construct the symmetric difference of elements in the passed in sets.
 When `s` is not an `AbstractSet`, the order is maintained.
-Note that in this case the multiplicity of elements matters.
 
 See also [`symdiff!`](@ref), [`setdiff`](@ref), [`union`](@ref) and [`intersect`](@ref).
 
@@ -261,11 +260,6 @@ julia> symdiff([1,2,3], [3,4,5], [4,5,6])
  6
 
 julia> symdiff([1,2,1], [2, 1, 2])
-2-element Vector{Int64}:
- 1
- 2
-
-julia> symdiff(unique([1,2,1]), unique([2, 1, 2]))
 Int64[]
 ```
 """
@@ -286,7 +280,9 @@ function symdiff!(s::AbstractSet, itrs...)
     return s
 end
 
-function symdiff!(s::AbstractSet, itr)
+symdiff!(s::AbstractSet, itr) = symdiff!(s::AbstractSet, Set(itr))
+
+function symdiff!(s::AbstractSet, itr::AbstractSet)
     for x in itr
         x in s ? delete!(s, x) : push!(s, x)
     end

diff --git a/base/bitset.jl b/base/bitset.jl
@@ -316,6 +316,13 @@ function symdiff!(s::BitSet, ns)
     return s
 end
 
+function symdiff!(s::BitSet, ns::AbstractSet)
+    for x in ns
+        int_symdiff!(s, x)
+    end
+    return s
+end
+
 function int_symdiff!(s::BitSet, n::Integer)
     n0 = _check_bitset_bounds(n)
     val = !(n0 in s)

diff --git a/test/arrayops.jl b/test/arrayops.jl
@@ -1136,7 +1136,7 @@ end
     @test isequal(setdiff([1,2,3,4], [7,8,9]), [1,2,3,4])
     @test isequal(setdiff([1,2,3,4], Int64[]), Int64[1,2,3,4])
     @test isequal(setdiff([1,2,3,4], [1,2,3,4,5]), Int64[])
-    @test isequal(symdiff([1,2,3], [4,3,4]), [1,2])
+    @test isequal(symdiff([1,2,3], [4,3,4]), [1,2,4])
     @test isequal(symdiff(['e','c','a'], ['b','a','d']), ['e','c','b','d'])
     @test isequal(symdiff([1,2,3], [4,3], [5]), [1,2,4,5])
     @test isequal(symdiff([1,2,3,4,5], [1,2,3], [3,4]), [3,5])

diff --git a/test/sets.jl b/test/sets.jl
@@ -393,9 +393,10 @@ end
     @test symdiff(Set([1]), BitSet()) isa Set{Int}
     @test symdiff(BitSet([1]), Set{Int}()) isa BitSet
     @test symdiff([1], BitSet()) isa Vector{Int}
-    # symdiff must NOT uniquify
-    @test symdiff([1, 2, 1]) == symdiff!([1, 2, 1]) == [2]
-    @test symdiff([1, 2, 1], [2, 2]) == symdiff!([1, 2, 1], [2, 2]) == [2]
+    #symdiff does uniquify
+    @test symdiff([1, 2, 1]) == symdiff!([1, 2, 1]) == [1,2]
+    @test symdiff([1, 2, 1], [2, 2]) == symdiff!([1, 2, 1], [2, 2]) == [1]
+    @test symdiff([1, 2, 1], [2, 2]) == symdiff!([1, 2, 1], [2, 2]) == [1]
 
     # Base.hasfastin
     @test all(Base.hasfastin, Any[Dict(1=>2), Set(1), BitSet(1), 1:9, 1:2:9,