overload show for mutable tangent

Author: oxinabox

src/tangent_types/structural_tangent.jl

@@ -334,7 +334,10 @@ Base.:(==)(a::Tangent{P}, b::Tangent{Q}) where {P,Q} = false
 
 Base.hash(a::Tangent, h::UInt) = Base.hash(backing(canonicalize(a)), h)
 
-function Base.show(io::IO, tangent::Tangent{P}) where {P}
+function Base.show(io::IO, tangent::StructuralTangent{P}) where {P}
+    if tangent isa MutableTangent
+        print(io, "Mutable")
+    end
     print(io, "Tangent{")
     str = sprint(show, P, context = io)
     i = findfirst('{', str)

test/tangent_types/structural_tangent.jl

@@ -398,6 +398,11 @@ end
             )
 
             @test repr(Tangent{Foo}()) == "Tangent{Foo}()"
+
+            @test ==(
+                repr(MutableTangent{MFoo}((;x=1.5, y=[1.0, 2.0]))),
+                "MutableTangent{MFoo}(x = 1.5, y = [1.0, 2.0])"
+            )
         end
 
         @testset "internals" begin