Merge pull request #621 from JuliaHomotopyContinuation/conversion_bug

Fix the bug in convert(type, Expression) from #615

src/model_kit/symengine.jl

@@ -701,19 +701,29 @@ function Base.convert(::Type{BigInt}, c::Basic)
 end
 
 function Base.convert(::Type{BigFloat}, c::Basic)
-    a = BigFloat()
-    ccall(
-        (:real_mpfr_get, libsymengine),
-        Nothing,
-        (Ref{BigFloat}, Ref{ExpressionRef}),
-        a,
-        c,
-    )
-    return a
+    if class(c) == :Integer
+        c1 = convert(Int, c)
+        return convert(BigFloat, c1)
+    else
+        a = BigFloat()
+        ccall(
+            (:real_mpfr_get, libsymengine),
+            Nothing,
+            (Ref{BigFloat}, Ref{ExpressionRef}),
+            a,
+            c,
+        )
+        return a
+    end
 end
 
 function Base.convert(::Type{Float64}, c::Basic)
-    return ccall((:real_double_get_d, libsymengine), Cdouble, (Ref{ExpressionRef},), c)
+    if class(c) == :Integer
+        c1 = convert(Int, c)
+        return convert(Float64, c1)
+    else
+        return ccall((:real_double_get_d, libsymengine), Cdouble, (Ref{ExpressionRef},), c)
+    end
 end
 
 function Base.real(x::Basic)

test/model_kit/symbolic_test.jl

@@ -329,4 +329,28 @@
         H_any = Homotopy(convert(Vector{Any}, h), [x, y, z], t)
         @test H_any isa Homotopy
     end
+
+    @testset "Convert" begin
+
+        @var x
+
+        s = x + 1 - x
+        @test convert(Int, s) == 1
+        @test convert(Int32, s) == Int32(1)
+        @test convert(Int64, s) == Int64(1)
+        @test convert(BigInt, s) == BigInt(1)
+        @test convert(BigFloat, s) == BigFloat(1)
+        @test convert(Float64, s) == Float64(1)
+        @test convert(ComplexF64, s) == ComplexF64(1)
+
+        r = x + 1.0 - x
+        @test convert(Float64, r) == Float64(1)
+        @test convert(ComplexF64, r) == ComplexF64(1)
+
+        u = x + BigFloat(1.0) - x
+        @test convert(BigFloat, u) == BigFloat(1.0)
+
+        t = x + (1.0 + 0.0im) - x
+        @test convert(ComplexF64, t) == ComplexF64(1)
+    end
 end