a callback function in programming is the ability to have a thing done later or recalled from a previous state to be acted upon

it's up to the programmer as to how they want to handle that state, after all the return function of a callback should still be handled, it's input has to be valid and the state must be managed

the arguments could result in errors, and their results must still be processed as that functions capabilities were definied in a previous point of the program, but it's good to still recoginze that this function which was previously defined and the memory of which has been passed along, it's good to keep these light and short, as they may happen frequently and therefore shouldn't be cumbersome.

consider running into a lover you'd previously known

it's a callback to the past, if that callback is long and lengthly it could become cumbersome and require a lot of usage and err continuously, making the program faulty, and crash

keep these light, fast, and if possible, bug free

type PastFlame = {
  name: string;
  sharedMemories?: string[];
};
 
type MemoryCallback = (lostFlame: PastFlame) => void;
 
const reminisce: MemoryCallback = (lostFlame) => {
  console.log(`Recalling the warmth of ${lostFlame.name}, ephemeral, yet vivid...`);
  if (lostFlame.sharedMemories?.length) {
    console.log(`Memories swirl: ${lostFlame.sharedMemories.join(', ')}`);
  }
};
 
const crossPaths = async (onReunion?: MemoryCallback): Promise<void> => {
  const input = prompt('Which memory do you feel crossing your path once more?')?.trim() ?? '';
 
  if (!input) {
    console.warn('No recollection surfaces—no callback triggered.');
    return;
  }
 
  console.log(`Fate has led you back to ${input} for just a moment...`);
 
  const oldAcquaintance: PastFlame = {
    name: input,
    sharedMemories: [
      'A concert once gone to',
      'A picnic at a park'
    ]
  };
 
  onReunion?.(oldAcquaintance);
};
 
crossPaths(reminisce);