fix up promotion and tests

Author: shashi

src/fast-terms.jl

@@ -23,7 +23,7 @@ function Add(T, coeff, dict)
         return coeff
     elseif _iszero(coeff) && length(dict) == 1
         k,v = first(dict)
-        return _isone(v) ? k : makemul(1, v, k)
+        return _isone(v) ? k : Mul(T, makemul(1, v, k)...)
     end
 
     Add{T, typeof(coeff), typeof(dict)}(coeff, dict, Ref{Any}(nothing))

src/methods.jl

@@ -84,11 +84,14 @@ for f in diadic
                    S::Type{<:Number}) = promote_type(T, S)
 end
 
-for f in [+, *, \, /, ^]
+for f in [+, -, *, \, /, ^]
     @eval promote_symtype(::$(typeof(f)),
                    T::Type{<:Number},
                    S::Type{<:Number}) = promote_type(T, S)
 end
+for f in [+, -, *]
+    @eval promote_symtype(::$(typeof(f)), T::Type{<:Number}) = T
+end
 
 promote_symtype(::typeof(rem2pi), T::Type{<:Number}, mode) = T
 Base.rem2pi(x::Symbolic, mode::Base.RoundingMode) = term(rem2pi, x, mode)

test/basics.jl

@@ -53,11 +53,11 @@ end
 @testset "Base methods" begin
     @syms w::Complex z::Complex a::Real b::Real x
 
-    @test isequal(w + z, Add(0, Dict(w=>1, z=>1)))
-    @test isequal(z + a, Add(0, Dict(z=>1, a=>1)))
-    @test isequal(a + b, Add(0, Dict(a=>1, b=>1))) # TODO: make this Real
-    @test isequal(a + x, Add(0, Dict(a=>1, x=>1)))
-    @test isequal(a + z, Add(0, Dict(a=>1, z=>1)))
+    @test isequal(w + z, Add(Number, 0, Dict(w=>1, z=>1)))
+    @test isequal(z + a, Add(Number, 0, Dict(z=>1, a=>1)))
+    @test isequal(a + b, Add(Real, 0, Dict(a=>1, b=>1)))
+    @test isequal(a + x, Add(Number, 0, Dict(a=>1, x=>1)))
+    @test isequal(a + z, Add(Number, 0, Dict(a=>1, z=>1)))
 
     # promote_symtype of identity
     @test isequal(Term(identity, [w]), Term{Complex}(identity, [w]))