Generic Type constraint from base classes, interfaces (Pass through)

The ability to allow extends type constraint to be an abstract specification of base class, interface.
This also prevent duplication, by having to define the type constraint twice, reduces the need for unnecessary intermediate interfaces.

type ID = string

interface IShape<TID extends ID, Neasted>{
    __ID: TID;
    __Neasted : Neasted
}

interface ITSShape<T, ID>
{
    __tsType: T;
    __ID: ID;
}

interface IShapeType extends IShape<'T', boolean | number | null>
{
}

Not possible

interface IShapeTSType<T extends ['__Neasted']> extends IShapeType
{
    __tsType : T;
}


interface IShapeTSType<T extends ['__Neasted']> extends IShape<'T', boolean | number | string>
{
    __tsType : T;
}


interface IShapeTSType<T extends this['__Neasted']> extends IShapeType
{
    __tsType : T;
}

interface IShapeTSType<T extends TShape['__Neasted'], TShape extends IShapeType> extends TShape
{
    __tsType : T;
}

• 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.

まず、提案されている IShape、IShapeType、IShapeTSType の例を分析し、意図されているジェネリック制約と継承のセマンティクスを明確にします。受け入れるべき構文を定義し、JavaScript の出力を変更せずに重複した制約を回避できることを確認します。この issue では実装ファイルもテストも指定されていません。