import { Primitive, bad, good, pure, sure } from './core.js'

export const literal = <
  // so that `as const` is not needed
  T extends Primitive,
>(
  value: T
) => {
  return sure(
    val => {
      if (val === value) {
        return good<T>(
          // @ts-expect-error We do an explicit check above
          val
        )
      }

      return bad(`not literal ${typeof value} (${String(value)})` as const)
    },
    {
      type: 'literal',
      value,
    }
  )
}

export const is = literal