@effect-ts/system/_src/Async/derive.ts

Effect-TS is a zero dependency set of libraries to write highly productive, purely functional TypeScript at scale.

// ets_tracing: off

import type { Has, Tag } from "../Has/index.js"
import type { Async } from "./core.js"
import * as has from "./has.js"

export type ShapeFn<T> = Pick<
  T,
  {
    [k in keyof T]: T[k] extends (
      ...args: infer ARGS
    ) => Async<infer R, infer E, infer A>
      ? ((...args: ARGS) => Async<R, E, A>) extends T[k]
        ? k
        : never
      : never
  }[keyof T]
>

export type ShapeCn<T> = Pick<
  T,
  {
    [k in keyof T]: T[k] extends Async<any, any, any> ? k : never
  }[keyof T]
>

export type DerivedLifted<
  T,
  Fns extends keyof ShapeFn<T>,
  Cns extends keyof ShapeCn<T>,
  Values extends keyof T
> = {
  [k in Fns]: T[k] extends (...args: infer ARGS) => Async<infer R, infer E, infer A>
    ? (...args: ARGS) => Async<R & Has<T>, E, A>
    : never
} & {
  [k in Cns]: T[k] extends Async<infer R, infer E, infer A>
    ? Async<R & Has<T>, E, A>
    : never
} & {
  [k in Values]: Async<Has<T>, never, T[k]>
}

export function deriveLifted<T>(
  H: Tag<T>
): <
  Fns extends keyof ShapeFn<T> = never,
  Cns extends keyof ShapeCn<T> = never,
  Values extends keyof T = never
>(
  functions: Fns[],
  effects: Cns[],
  values: Values[]
) => DerivedLifted<T, Fns, Cns, Values> {
  return (functions, constants, values) => {
    const ret = {} as any

    for (const k of functions) {
      // @ts-expect-error
      ret[k] = (...args: any[]) => has.accessServiceM(H)((h) => h[k](...args))
    }

    for (const k of constants) {
      // @ts-expect-error
      ret[k] = has.accessServiceM(H)((h) => h[k])
    }

    for (const k of values) {
      ret[k] = has.accessService(H)((h) => h[k])
    }

    return ret as any
  }
}

export type DerivedAccessM<T, Gens extends keyof T> = {
  [k in Gens]: <R_, E_, A_>(
    f: (_: T[k]) => Async<R_, E_, A_>,
    __trace?: string
  ) => Async<R_ & Has<T>, E_, A_>
}

export function deriveAccessM<T>(
  H: Tag<T>
): <Gens extends keyof T = never>(generics: Gens[]) => DerivedAccessM<T, Gens> {
  return (generics) => {
    const ret = {} as any

    for (const k of generics) {
      ret[k] = (f: any) => has.accessServiceM(H)((h) => f(h[k]))
    }

    return ret as any
  }
}

export type DerivedAccess<T, Gens extends keyof T> = {
  [k in Gens]: <A_>(f: (_: T[k]) => A_, __trace?: string) => Async<Has<T>, never, A_>
}

export function deriveAccess<T>(
  H: Tag<T>
): <Gens extends keyof T = never>(generics: Gens[]) => DerivedAccess<T, Gens> {
  return (generics) => {
    const ret = {} as any

    for (const k of generics) {
      ret[k] = (f: any) => has.accessService(H)((h) => f(h[k]))
    }

    return ret as any
  }
}