Update

src/Nonlinear/parse.jl

@@ -67,7 +67,8 @@ function _parse_without_recursion_inner(stack, data, expr, x, parent)
     end
     push!(expr.nodes, Node(node_type, id, parent))
     parent = length(expr.nodes)
-    # Args need to be pushed onto the stack in reverse
+    # Args need to be pushed onto the stack in reverse because the stack is a
+    # first-in last-out datastructure.
     for arg in reverse(x.args)
         push!(stack, (parent, arg))
     end

src/attributes.jl

@@ -1857,9 +1857,9 @@ function attribute_value_type(::ConstraintConflictStatus)
 end
 
 """
-    UserDefinedFunction(name::Symbol, N::Int)
+    UserDefinedFunction(name::Symbol, arity::Int)
 
-Set a user-defined function by the name of `Name` with `N` arguments.
+Set a user-defined function by the name of `Name` with `arity` arguments.
 
 The value to be set is a tuple containg one to three functions, representing the
 zero, first, and second-order derivatives of the function.
@@ -1883,7 +1883,7 @@ MOI.set(model, MOI.UserDefinedFunction(:f, 2), (f, ∇f, ∇²f))
 """
 struct UserDefinedFunction <: AbstractModelAttribute
     name::Symbol
-    N::Int
+    arity::Int
 end
 
 """