Distinguish between plain object types and class types

Search Terms

• plain object class type

Suggestion

Some way to distinguish an object type that only has Object in its prototype chain.

Use Cases

In this library, we use mapped types to convert immutable objects/arrays into their mutable representation. We never do this for class instances, so I need a way to skip the mapped type when an object type is actually a class type (in order to preserve readonly properties on class instances).

Examples

I have no suggestions for such syntax.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Related

https://stackoverflow.com/questions/53819550/distinguish-between-plain-objects-and-class-types#53819550

Beginne mit dem Vorschlag und seinem Immer-Anwendungsfall und sieh dir dann die verknüpfte Stack Overflow-Diskussion und die TypeScript Design Goals im Issue an. Erledigt wäre die Aufgabe, wenn ein klar spezifizierter Mechanismus des Typsystems zur Unterscheidung von Typen einfacher Objekte und Klassentypen vorliegt und sein Verhalten und seine Syntax vereinbart sind.