// @flow
type FieldName = string
export type FieldPattern = FieldName | RegExp | FieldName[]
export type UpdatesByName = {
  [FieldName]: (value: any, allValues: ?Object, prevValues: ?Object,) => any
}
export type UpdatesForAll = (
  value: any,
  field: string,
  allValues: ?Object,
  prevValues: ?Object
) => { [FieldName]: any }
export type Updates = UpdatesByName | UpdatesForAll

export type Calculation = {
  field: FieldPattern,
  isEqual?: (any, any) => boolean,
  updates: Updates
}