Let @validate check that index vectors are unique

src/Sets/Line2D/project.jl

@@ -5,30 +5,24 @@
     if m == 2
         @inbounds if block[1] == 1 && block[2] == 2
             return L  # no projection
-        elseif block[1] == 2 && block[2] == 1
-            return Line2D(L.a[block], L.b)  # swap a vector
-        else
-            throw(ArgumentError("invalid projection to $block"))
         end
-    elseif m == 1
-        # projection to dimension i
-        cdims = constrained_dimensions(L)
-        if length(cdims) == 1
-            @inbounds if cdims[1] == block[1]
-                # L: aᵢxᵢ = b where aᵢ ≠ 0
-                return Singleton([L.b / L.a[cdims[1]]])
-            else
-                # L: aⱼxⱼ = b where i ≠ j
-                return Universe{N}(1)
-            end
+        # block[1] == 2 && block[2] == 1
+        return Line2D(L.a[block], L.b)  # swap a vector
+    end
+    # projection to 1 dimension
+    cdims = constrained_dimensions(L)
+    if length(cdims) == 1
+        @inbounds if cdims[1] == block[1]
+            # L: aᵢxᵢ = b where aᵢ ≠ 0
+            return Singleton([L.b / L.a[cdims[1]]])
         else
-            # L is constrained in both dimensions
-            @assert length(cdims) == 2
+            # L: aⱼxⱼ = b where i ≠ j
             return Universe{N}(1)
         end
-    else
-        throw(ArgumentError("cannot project a two-dimensional line to $m dimensions"))
     end
+    # L is constrained in both dimensions
+    @assert length(cdims) == 2
+    return Universe{N}(1)
 end
 
 """

src/Validation/common.jl

@@ -40,5 +40,9 @@ function validate_index_vector(v::AbstractVector{Int}, X::LazySet; fun::Function
                                     "for dimension $n but received the vector $v"))
         end
     end
+    if length(unique(v)) < length(v)
+        throw(ArgumentError("`$(string(fun))` requires an index vector " *
+                            "without duplicates but received the vector $v"))
+    end
     return true
 end

test/Sets/EmptySet.jl

@@ -241,13 +241,15 @@ for N in @tN([Float64, Float32, Rational{Int}])
     @test_throws DimensionMismatch permute(E, [1])
     @test_throws DimensionMismatch permute(E, [1, -1])
     @test_throws DimensionMismatch permute(E, [1, 3])
+    @test_throws ArgumentError permute(E, [1, 1])
     E2 = permute(E, [2, 1])
     @test isidentical(E, E2)
 
     # project
     @test_throws DimensionMismatch project(E, [1, 2, 3])
     @test_throws DimensionMismatch project(E, [1, -1])
     @test_throws DimensionMismatch project(E, [1, 3])
+    @test_throws ArgumentError project(E, [1, 1])
     E2 = project(E, [2])
     @test E2 isa EmptySet{N} && dim(E2) == 1
 

test/Sets/Universe.jl

@@ -254,13 +254,15 @@ for N in @tN([Float64, Float32, Rational{Int}])
     @test_throws DimensionMismatch permute(U, [1])
     @test_throws DimensionMismatch permute(U, [1, -1])
     @test_throws DimensionMismatch permute(U, [1, 3])
+    @test_throws ArgumentError permute(U, [1, 1])
     U2 = permute(U, [2, 1])
     @test isidentical(U, U2)
 
     # project
     @test_throws DimensionMismatch project(U, [1, 2, 3])
     @test_throws DimensionMismatch project(U, [1, -1])
     @test_throws DimensionMismatch project(U, [1, 3])
+    @test_throws ArgumentError project(U, [1, 1])
     U2 = project(U, [2])
     @test U2 isa Universe{N} && dim(U2) == 1