adit-hotstar

type Then<A> = {
    (onFulfilled?: null, onRejected?: ((reason: unknown) => A | Thenable<A>) | null): Thenable<A>;
    <B>(onFulfilled: (value: A) => B | Thenable<B>, onRejected?: ((reason: unknown) => B | Thenable<B>) | null): Thenable<B>;
};

interface Thenable<A> {
    then: Then<A>;
}

type PromiseState<A> =

adit-hotstar

The time when a program is executed, i.e. compile time or runtime, has nothing to do with whether that program is pure or impure.

• You can execute pure programs at compile time.
• You can execute pure programs at runtime.
• You can execute impure programs at compile time.
• You can execute impure programs at runtime.

For example, consider the following program.

adit-hotstar

const stringify = (json, indent = 0) => {
  if (json === null || typeof json !== 'object') return JSON.stringify(json);

  const indentation = `\n${' '.repeat(indent)}`;

  if (Array.isArray(json)) {
    const { length } = json;

    if (length === 0) return '[]';