koa-lite/examples/co.js

var koa = require('..');
var fs = require('co-fs');
var app = koa();

// read docs/*.md in parallel
// and return a joined response

app.use(function(){
  return function *(){
    var paths = yield fs.readdir('docs');

    var files = yield paths.map(function(path){
      return fs.readFile('docs/' + path, 'utf8');
    });

    this.type = 'markdown';
    this.body = files.join('');
  }
});

app.listen(3000);