API Design

fetch

{ 
  type: 'fetch',
  value: 'http://xxx.json',
  format: 'csv' | 'json',
  // detect data types such as dates and booleans and convert values to the corresponding JS type.
  autoType?: true | false,
}

filterBy

// Filter field with different callback. 
{ type: 'filterBy', fields: [ ['time', callback], ['count', callback] }

sortBy

// true => asc; false => desc
{ type: 'sortBy', fields: [ ['time', true], ['count', false] ] }

map

// Handle array data with callback.
{ type: 'map', callback: data => data }

custom

// Handle any type data with callback.
{ type: 'custom', callback: data => data }