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

/**
 * Defined using the `sure` function
 *
 * This adds a `{ meta: undefined }` to the passed function
 */
export const string = sure(
  x => {
    return typeof x === 'string' //
      ? good(x)
      : bad('not string' as const)
  },
  {
    type: 'string' as const,
  }
)

/**
 * Defined using the `pure` function
 *
 * The pure function returnes exactly the passed function
 */
export const number = sure(
  x => {
    return typeof x === 'number' //
      ? good(x)
      : bad('not number' as const)
  },
  {
    type: 'number' as const,
  }
)

/**
 * Defined without using the `sure` or `pure` functions
 *
 * This is the same as the `pure` function
 */
export const boolean = (x: unknown) => {
  return typeof x === 'boolean' //
    ? good(x)
    : bad('not boolean' as const)
}

export const undef = (value: unknown) => {
  return value === undefined //
    ? good(value)
    : bad('not undefined' as const)
}

export const nil = (value: unknown) => {
  return value === null //
    ? good(value)
    : bad('not null' as const)
}

export const unknown = pure(x => good(x))