Add tests for SymEngine code; rename and fix free_symbols

src/Initialization/init_SymEngine.jl

@@ -67,14 +67,15 @@ julia> free_symbols(:(x1 + x2 <= 2*x4 + 6), HalfSpace)
  x4
 ```
 """
-function free_symbols(::Expr, ::Type{<:LazySet}) end
+function free_symbols(::Expr, ::Type{<:LazySet}) end  # COV_EXCL_LINE
 
-function free_symbols(expr::Expr)
+# Note: this convenience function is not used anywhere
+function _free_symbols(expr::Expr)
     if _is_hyperplane(expr)
-        return free_symbols(expr, HyperPlane)
+        return free_symbols(expr, Hyperplane)
     elseif _is_halfspace(expr)
-        return free_symbols(expr, Halfspace)
+        return free_symbols(expr, HalfSpace)
     else
-        error("the free symbols for the expression $(expr) is not implemented")
+        error("the `free_symbols` method for the expression $expr is not implemented")
     end
 end

src/Sets/HalfSpace/init_SymEngine.jl

@@ -3,7 +3,7 @@ import .SymEngine: free_symbols
 function free_symbols(expr::Expr, ::Type{<:HalfSpace})
     # get sides of the inequality
     lhs, rhs = convert(SymEngine.Basic, expr.args[2]), convert(SymEngine.Basic, expr.args[3])
-    return free_symbols(lhs - rhs)
+    return SymEngine.free_symbols(lhs - rhs)
 end
 
 eval(load_SymEngine_ishalfspace())

src/Sets/Hyperplane/init_SymEngine.jl

@@ -7,7 +7,7 @@ function free_symbols(expr::Expr, ::Type{<:Hyperplane})
     # treats the 4 in :(2*x1 = 4)
     rhs = :args in fieldnames(typeof(expr.args[2])) ? convert(SymEngine.Basic, expr.args[2].args[2]) :
             convert(SymEngine.Basic, expr.args[2])
-    return free_symbols(lhs - rhs)
+    return SymEngine.free_symbols(lhs - rhs)
 end
 
 eval(load_SymEngine_ishyperplanar())

test/Interfaces/SymEngine.jl

@@ -0,0 +1,10 @@
+# _is_linearcombination
+@test LazySets._is_linearcombination(:(2*x1 - 4))
+@test LazySets._is_linearcombination(:(6.1 - 5.3*f - 0.1*g))
+@test !LazySets._is_linearcombination(:(2*x1^2))
+@test !LazySets._is_linearcombination(:(x1^2 - 4*x2 + x3 + 2))
+
+# _free_symbols
+@test LazySets._free_symbols(:(x1 = 1)) == [SymEngine.Basic(:(x1))]
+@test LazySets._free_symbols(:(2*x2 <= 4)) == [SymEngine.Basic(:(x2))]
+@test_throws ErrorException LazySets._free_symbols(:(x3 != 4))

test/Project.toml

@@ -24,6 +24,7 @@ SCS = "c946c3f1-0d1f-5ce8-9dea-7daa1f7e2d13"
 SetProg = "39881422-4b75-5582-a5c7-0feb14562a65"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+SymEngine = "123dc426-2d89-5057-bbad-38513e3affd8"
 Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 TaylorModels = "314ce334-5f6e-57ae-acf6-00b6e903104a"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
@@ -52,6 +53,7 @@ RecipesBase = "0.6 - 0.8, 1"
 SCS = "1, 2"
 SetProg = "0.3"
 StaticArrays = "0.12, 1"
+SymEngine = "0.7 - 0.12"
 Symbolics = "1 - 5"
 TaylorModels = "0.0.1, 0.1 - 0.7"
 WriteVTK = "1"

test/Sets/HalfSpace.jl

@@ -196,7 +196,6 @@ for N in [Float64, Float32]
 end
 
 for N in [Float64]
-
     # rationalization
     H = HalfSpace([1.0, 2.0], 0.0)
     Hr = rationalize(H)
@@ -252,6 +251,32 @@ for N in [Float64]
         @test HalfSpace(2x[1] + 5x[4] >= -10.0 + x[3], x) ==
               HalfSpace([-2.0, 0.0, 1.0, -5.0, 0.0], 10.0)
     end
+
+    # tests that require SymEngine
+    @static if isdefined(@__MODULE__, :SymEngine)
+        # _is_halfspace
+        @test all(LazySets._is_halfspace.([:(x1 <= 0), :(x1 < 0), :(x1 > 0), :(x1 >= 0)]))
+        @test !LazySets._is_halfspace(:(x1 = 0))
+        @test LazySets._is_halfspace(:(2*x1 <= 4))
+        @test LazySets._is_halfspace(:(6.1 <= 5.3*f - 0.1*g))
+        @test !LazySets._is_halfspace(:(2*x1^2 <= 4))
+        @test !LazySets._is_halfspace(:(x1^2 > 4*x2 - x3))
+        @test LazySets._is_halfspace(:(x1 > 4*x2 - x3))
+
+        # convert
+        H = convert(HalfSpace, :(x1 <= -0.03))
+        @test  H == HalfSpace([1.0], -0.03)
+        H = convert(HalfSpace, :(x1 < -0.03))
+        @test H == HalfSpace([1.0], -0.03)
+        H = convert(HalfSpace, :(x1 > -0.03))
+        @test H == HalfSpace([-1.0], 0.03)
+        H = convert(HalfSpace, :(x1 >= -0.03))
+        @test H == HalfSpace([-1.0], 0.03)
+        H = convert(HalfSpace, :(x1 + x2 <= 2*x4 + 6))
+        @test H == HalfSpace([1.0, 1.0, -2.0], 6.0)
+        H = convert(HalfSpace, :(x1 + x2 <= 2*x4 + 6), vars=SymEngine.Basic[:x1, :x2, :x3, :x4])
+        @test H == HalfSpace([1.0, 1.0, 0.0, -2.0], 6.0)
+    end
 end
 
 # isoperationtype

test/Sets/Hyperplane.jl

@@ -203,6 +203,28 @@ for N in [Float64]
         vars = @variables x[1:2] t
         @test Hyperplane(x[1] == t, vars) == Hyperplane([1.0, 0.0, -1.0], 0.0)
     end
+
+    # tests that require SymEngine
+    @static if isdefined(@__MODULE__, :SymEngine)
+        # _is_halfspace
+        @test LazySets._is_hyperplane(:(x1 = 0))
+        @test !LazySets._is_hyperplane(:(x1 <= 0))
+        @test LazySets._is_hyperplane(:(2*x1 = 4))
+        @test LazySets._is_hyperplane(:(6.1 = 5.3*f - 0.1*g))
+        @test !LazySets._is_hyperplane(:(2*x1^2 = 4))
+        @test !LazySets._is_hyperplane(:(x1^2 = 4*x2 - x3))
+        @test LazySets._is_hyperplane(:(x1 = 4*x2 - x3))
+
+        # convert
+        H = convert(Hyperplane, :(x1 = -0.03))
+        @test H == Hyperplane([1.0], -0.03)
+        H = convert(Hyperplane, :(x1 + 0.03 = 0))
+        @test H == Hyperplane([1.0], -0.03)
+        H = convert(Hyperplane, :(x1 + x2 = 2*x4 + 6))
+        @test H == Hyperplane([1.0, 1.0, -2.0], 6.0)
+        H = convert(Hyperplane, :(x1 + x2 = 2*x4 + 6), vars=SymEngine.Basic[:x1, :x2, :x3, :x4])
+        @test H == Hyperplane([1.0, 1.0, 0.0, -2.0], 6.0)
+    end
 end
 
 # isoperationtype

test/runtests.jl

@@ -51,7 +51,7 @@ Random.seed!(1234)
     end
     using IntervalMatrices: ±, IntervalMatrix
     using TaylorModels: set_variables, TaylorModelN
-    using Symbolics
+    using SymEngine, Symbolics
 end
 
 # ==============================
@@ -107,6 +107,9 @@ if test_suite_basic
     @testset "LazySets.CDDLib" begin
         include("Interfaces/CDDLib.jl")
     end
+    @testset "LazySets.SymEngine" begin
+        include("Interfaces/SymEngine.jl")
+    end
 
     # =======================
     # Testing basic set types