gistfile1.js

var raven        = require('raven')
  , Promise      = require('bluebird')
  , requestAsync = require('request-promise')

var redis = Promise.promisifyAll(require('redis').createClient())

var languages = JSON.parse(require('fs').readFileSync(__dirname + '/languages.json')).languages

Promise.all(languages.map(function(language){
   return redis.setAsync('lang:'+language.tag+':name', language.name)
   .then(_ => Promise.all(language.cats.map(cat => pushSubCategories(cat, language))))
}))
.done(function(){ redis.quitAsync() })

function pushSubCategories(category, language, depth){ 
   if (typeof depth != 'number') depth = 0
   console.log('woo', depth)
   return redis.saddAsync('lang:'+language.tag+':cats', category)
   .then(_ => {
      console.log(language.tag+' '+depth+':', category)

      return requestAsync({
         url: <...>
       , json: true
       , transform: function(resp){ return resp.query.categorymembers }
      })
      .map(member => (depth < 3) ? pushSubCategories(member, language, depth + 1) : null)
   })
}