A printf with dependant types in TypeScript, similar to Idris (https://gist.github.com/chrisdone/672efcd784528b7d0b7e17ad9c115292)

Console-TemplateLiteralFormatSpecifiers.ts

///<reference lib="dom"/>

//#region Implementation

type FieldType<Field> = 
  's' extends Field ? string      :
  'f' extends Field ? number      :
  'i' extends Field ? number      :
  'd' extends Field ? number      :
  'o' extends Field ? HTMLElement :
  'O' extends Field ? object      :
  'c' extends Field ? string      : never;

type ExtractFields<T> =
    T extends `${infer _}%${infer Field}${infer R}` 
        ? [FieldType<Field>, ...ExtractFields<R>] :
    T extends `${infer _}%${infer Field}` 
        ? [FieldType<Field>] :
    [ ];

//#endregion Implementation

//#region Integration

interface Console 
{
    // All the methods process format specifiers, iirc
    log<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    info<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    debug<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    warn<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    error<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    trace<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    group<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
    groupCollapsed<Fmt extends string>(fmt: Fmt, ...args: ExtractFields<Fmt>): void;
}

//#endregion Integration

console.log("Stuff: %s %f %O", 'Hello', 123, { ok: true });