Function decorate

Solutions/9_3/structly/validate.py:108–134

(func)

    retcheck = annotations.pop('return_', None)

    def decorate(func):
        sig = signature(func)

        @wraps(func)
        def wrapper(*args, **kwargs):
            bound = sig.bind(*args, **kwargs)
            errors = []

            # Enforce argument checks
            for name, validator in annotations.items():
                try:
                    validator.check(bound.arguments[name])
                except Exception as e:
                    errors.append(f'    {name}: {e}')

            if errors:
                raise TypeError('Bad Arguments\n' + '\n'.join(errors))

            result = func(*args, **kwargs)

            if retcheck:
                try:
                    retcheck.check(result)
                except Exception as e:
                    raise TypeError(f'Bad return: {e}') from None
            return result
        return wrapper
    return decorate

# Examples