ggrandi

One possible way we could handle errors would be like this: [(playground link)](https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAbzgMQHYBo4GVMGECGANoZgCpwC+cAZlBCHAEQAWEMAzgMZTBgyMBuAFAiAJgFNOhfFHFxOEVO3gBRKHSgBZce3b4A5uIBccAK6pgAR1Nz2ATxAAjCIWEw7YOWo0AeFQD44AF5EITg4AG1vaG1dA3EAXRMVIQoRAHp0uFkJamBUOQADAAVecUK4GAg4ZQgwOGBqSuY5fE5OUxBTaSqoOGZ8djh8VDhxdWg4AAp8ADcIYFEh7nF8GHz9YcrxcGgZOzhZmWB8R0JxAEohd084Us8fNs5MAA8h8ReYcVQllFQIhKBIJhSoecQQJrRLQ6PSGMafb6-ADW4jsEOG7RBAH4MZwQSY3vCvj8hhEQeF8tRxjRgFBlETEUM0OhyXAAHQcynU2T0j7E35oAEghLYu5lHwEYg+PJ0mCYJ7+TA8mD+fG44QZLIAWh18Pw4HOZlhch1WpE+S+UGobTkpGYdAA7gBJagAOTYWBgPFQ+kaJzOcj5jL+oXCEFMMDAEZMMGYwHYEUYMn07EYCQiAAYEgySdg2Z7vb68qdDTjY-HE8nU+ms3BkhMoD5GCoXp5OF9RFtlIXGKq0tcwdh8HZYsafKQgWKHqRMBE7Y6Xe6YAWNn6S+JMFg2cVZJ4fk3R-ETL3ASIbnIAEoARmCQ5HMPiPnsThcqsy8Lb8EK57g19vSCiBtD0MJImBbT9xE7fBsC9DZGEoQoz0HC8ACZbywYdgPEHwrzfLIPk-OBv2QtCQkYLCTCvRhEKEd8HQGeB2FYbpOwGMA936cZxCxAdbgvABmW97mwiIr0wZ9nEIBJZ1INlNHwMBx3tCBnTdD1YJ9NcA38QEgA) ```ts declare const ErrorMessage: unique symbol; type Error = { [ErrorMessage]: E } // redefine `Pipe` to...

The only way I know to make sure that a callback has at least one argument is by using a generic like this (based on Array\.some): ```ts declare const some:...

That is fine by me