[Tools] #tools #maybe #wait #if #case

CASE.md

export function CASE<T>(...args: [boolean, T][]) {
  return args.find(a => a[0])?.[1]
}

Example:

CASE(
  [
    status.type === StatusType.ERROR,
    h(AppError, { message: status.message })
  ],
  [status.type === StatusType.INIT, h(AppInit)],
  [
    true,
    div('.branding-below', [
      div('.prop.header', [
        div('.name', span('Наименование')),
        div('.value', span('Значение'))
      ]),
      div(
        properties.filter(p => p.value !== null).map(p => h(Property, p))
      ),
      div(h(Draft, draft))
    ])
  ]
)

IF.ts

export function IF<T, F>(condition: unknown, trueValue: T, falseValue?: F) {
  return condition ? trueValue : falseValue
}

maybe.ts

export function MAYBE<T>(value: T): [NonNullable<T>] {
  if (value != null) {
    return [value as NonNullable<T>]
  } else {
    return [] as any
  }
}

wait.ts

export function wait(ms: number) {
  return new Promise(resolve => setTimeout(resolve, ms))
}