From f100b5ed7b307ad5b7f2608af0e43fd6d5e55b84 Mon Sep 17 00:00:00 2001
From: Shashi Gowda <gowda@mit.edu>
Date: Tue, 30 Mar 2021 01:05:42 +0530
Subject: [PATCH] make number methods defined only on Symbolic{<:Number}

Co-authored-by: "Yingbo Ma" <mayingbo5@gmail.com>
---
 Project.toml   |  2 +-
 src/methods.jl | 10 +++++-----
 src/types.jl   |  3 +--
 test/basics.jl |  7 +++++++
 4 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/Project.toml b/Project.toml
index ea9efbcfb..d98ba79d8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "SymbolicUtils"
 uuid = "d1185830-fcd6-423d-90d6-eec64667417b"
 authors = ["Shashi Gowda"]
-version = "0.9.4"
+version = "0.10.0"
 
 [deps]
 AbstractAlgebra = "c3fe647b-3220-5bb0-a1ea-a7954cac585d"
diff --git a/src/methods.jl b/src/methods.jl
index 6dc358513..b8dc91f95 100644
--- a/src/methods.jl
+++ b/src/methods.jl
@@ -94,14 +94,14 @@ for f in [+, -, *, \, /, ^]
 end
 
 promote_symtype(::typeof(rem2pi), T::Type{<:Number}, mode) = T
-Base.rem2pi(x::Symbolic, mode::Base.RoundingMode) = term(rem2pi, x, mode)
+Base.rem2pi(x::Symbolic{<:Number}, mode::Base.RoundingMode) = term(rem2pi, x, mode)
 
 for f in monadic
     if f in [real]
         continue
     end
     @eval promote_symtype(::$(typeof(f)), T::Type{<:Number}) = promote_type(T, Real)
-    @eval (::$(typeof(f)))(a::Symbolic)   = term($f, a)
+    @eval (::$(typeof(f)))(a::Symbolic{<:Number})   = term($f, a)
 end
 
 Base.:*(a::AbstractArray, b::Symbolic{<:Number}) = map(x->x*b, a)
@@ -112,7 +112,7 @@ for f in [identity, one, zero, *, +, -]
 end
 
 promote_symtype(::typeof(Base.real), T::Type{<:Number}) = Real
-Base.real(s::Symbolic) = islike(s, Real) ? s : term(real, s)
+Base.real(s::Symbolic{<:Number}) = islike(s, Real) ? s : term(real, s)
 
 ## Booleans
 
@@ -148,5 +148,5 @@ promote_symtype(::typeof(ifelse), _, ::Type{T}, ::Type{S}) where {T,S} = Union{T
 Base.@deprecate cond(_if, _then, _else) ifelse(_if, _then, _else)
 
 # Specially handle inv and literal pow
-Base.inv(x::Symbolic) = Base.:^(x, -1)
-Base.literal_pow(::typeof(^), x::Symbolic, ::Val{p}) where {p} = Base.:^(x, p)
+Base.inv(x::Symbolic{<:Number}) = Base.:^(x, -1)
+Base.literal_pow(::typeof(^), x::Symbolic{<:Number}, ::Val{p}) where {p} = Base.:^(x, p)
diff --git a/src/types.jl b/src/types.jl
index c288cea16..98cc50eaa 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -543,8 +543,7 @@ showraw(t) = showraw(stdout, t)
 
 sdict(kv...) = Dict{Any, Number}(kv...)
 
-# this cannot be Symbolic{<:Number} to make MTK Parameters work. See #155
-const SN = Symbolic
+const SN = Symbolic{<:Number}
 """
     Add(T, coeff, dict::Dict)
 
diff --git a/test/basics.jl b/test/basics.jl
index 50f3c1f4f..a1d396415 100644
--- a/test/basics.jl
+++ b/test/basics.jl
@@ -174,3 +174,10 @@ end
     @test hash(a + b, UInt(0)) === hash(a + b) === hash(a + b, UInt(0)) # test caching
     @test hash(a + b, UInt(2)) !== hash(a + b)
 end
+
+@testset "methoderror" begin
+    @syms a::Any b::Any
+
+    @test_throws MethodError a * b
+    @test_throws MethodError a + b
+end