hash for Equation

Author: shashi

src/equations.jl

@@ -13,6 +13,7 @@ struct Equation
     rhs::Expression
 end
 Base.:(==)(a::Equation, b::Equation) = isequal((a.lhs, a.rhs), (b.lhs, b.rhs))
+Base.hash(a::Equation, salt::UInt) = hash(a.lhs, hash(a.rhs, salt))
 
 """
 $(TYPEDSIGNATURES)

test/operation_overloads.jl

@@ -15,6 +15,8 @@ aa = a; # old a
 
 @test isequal(get_variables(a+aa+1), [a])
 
+@test hash(a+b ~ c+d) == hash(a+b ~ c+d)
+
 # test some matrix operations don't throw errors
 X = [a b;c d]
 det(X)