Merge pull request #2079 from SciML/myb/wrap

Rewrap after unwrap in `apply_to_variables`

Author: YingboMa

src/systems/abstractsystem.jl

@@ -371,14 +371,15 @@ function Base.setproperty!(sys::AbstractSystem, prop::Symbol, val)
     end
 end
 
-function apply_to_variables(f::F, ex) where {F}
-    ex = value(ex)
+apply_to_variables(f::F, ex) where {F} = _apply_to_variables(f, ex)
+apply_to_variables(f::F, ex::Num) where {F} = wrap(_apply_to_variables(f, unwrap(ex)))
+function _apply_to_variables(f::F, ex) where {F}
     if isvariable(ex)
         return f(ex)
     end
     istree(ex) || return ex
-    similarterm(ex, apply_to_variables(f, operation(ex)),
-                map(Base.Fix1(apply_to_variables, f), arguments(ex)),
+    similarterm(ex, _apply_to_variables(f, operation(ex)),
+                map(Base.Fix1(_apply_to_variables, f), arguments(ex)),
                 metadata = metadata(ex))
 end
 

test/variable_scope.jl

@@ -9,6 +9,7 @@ using Test
 b = ParentScope(b)
 c = ParentScope(ParentScope(c))
 d = GlobalScope(d)
+@test all(x -> x isa Num, [b, c, d])
 
 # ensure it works on Term too
 LocalScope(e.val)