E-SE0010 — Calling a function already applied by the decorator

Error Type	Syntax Error
Phase	calling a function already applied by the decorator API
Python exception	`ValueError` (builtin)

Message

The function `{name}` was already applied by the `@problem.update` decorator and cannot be called again.

Its updates are already reflected in the problem.

Possible fix: use the problem object you decorated directly.

({name} is the name of the original decorated function)

Cause

When @problem.update processes a function, it runs the function body exactly once to update the problem and replaces the function’s name with a placeholder object that cannot be called. This error is raised when that placeholder is called afterwards, typically because the code tries to invoke the decorated function by hand.

problem = jm.Problem("My Problem")

@problem.update
def build(problem: jm.DecoratedProblem):
    w = problem.Float(ndim=1)
    x = problem.BinaryVar(shape=(w.len_at(0),))
    problem += jm.sum(w * x)

build()  # `build` was already applied by the decorator

Fix

Do not call the decorated function: its updates are already reflected in the problem, and the decorator does not return a new problem object. Continue working with the original problem object you decorated, for example by evaluating it with instance data.

instance = problem.eval(instance_data)