545 - printf (with original argument names)

[BOCbMOU]

type FormatTypes = {
  s: [s1: string];
  d: [d1: number];
}

type Format<T extends string> = T extends `${string}%%${infer TRest extends string}` ? Format<TRest> : (
  T extends `${string}%${infer F extends keyof FormatTypes}${infer TRest extends string}` ? (
    (...args: FormatTypes[F]) => Format<TRest>
  ) : string
)

type T = Format<'a%dbc%s'> // type T = (d1: number) => (s1: string) => string 

[BOCbMOU]

One more solution:

type FormatTypes<T = never> = {
  s: (s1: string) => T;
  d: (d1: number) => T;
}

type Format<T extends string> = 
  T extends `${string}%${infer F extends keyof FormatTypes | '%'}${infer TRest extends string}` ? (
    F extends keyof FormatTypes ? (
      FormatTypes<Format<TRest>>[F]
    ) : Format<TRest>
  ) : string