Helper functions for merging and selecting

[heho]

It would be useful to have type safe helper functions for merging Record<Slots, string> or selecting several of those slots, I also found being able to rename slots quite helpful. Something along the lines of:

type ClassRecord = Record<Slots, string>

function mergeClassesDeep
    <C1 extends ClassRecord, C2 extends ClassRecord>
    (cf1: (() => C1) | undefined, cf2: ((() => C2)) | undefined): () => C1 & C2
    
function mergeClassesDeep
    <C1 extends ClassRecord, C2 extends ClassRecord, C3 extends ClassRecord>
    (cf1: (() => C1) | undefined, cf2: (() => C2) | undefined, cf3: (() => C3) | undefined): () => C1 & C2 & C3
    
//...

export function selectSlots
    <T extends ClassRecord, K1 extends keyof T>
    (record: T, key1: K1): Pick<T, K1>

export function selectSlots
    <T extends ClassRecord, K1 extends keyof T, K2 extends keyof T>
    (record: T, key1: K1, key2: K2): Pick<T, K1 | K2>
    
//...

export function renameSlots
    <T extends ClassRecord, K1 extends keyof T, R1 extends SlotType>
    (styleFunction: T, mapping1: [K1, R1]): Omit<T, K1> & ClassRecord<R1>

export function renameSlots
    <T extends ClassRecord, K1 extends keyof T, R1 extends SlotType, K2 extends keyof T, R2 extends SlotType>
    (record: T, mapping1: [K1, R1], mapping2: [K2, R2]): Omit<T, K1 | K2> & ClassRecord<R1 | R2>

I would much prefer if mapping was a Record, but I am not sure if it is possible to make that type safe.

[layershifter]

Sorry but I did not get 🐱

Do need some help with your implementation? Or is it a feature request to add new functionality? If it's a feature request please explain what these functions do and in which scenarios they are useful.

[layershifter]

Closing for housekeeping, but feel free to follow up.