dtipson

const program = (...list) => 
                      acc =>
                      R.flatten(list).reduce( (acc,fn) => acc.then(fn), Promise.resolve(acc));

dtipson

const program = (...list) => acc => list.reduce( (acc,fn) => acc.then(fn), Promise.resolve(acc));

dtipson

const bind = function(aPromise, f) {
  return aPromise.then(f);
},

pipe = _.curry(function(functionList, aPromise) {
  return _.reduce(functionList, bind, aPromise);
}),
//even_cleaner_pipe = _.curry(_.partial(_.reduce,_, bind),2)

program = function(/*...list of functions*/){

dtipson

getUserCommentsbyId = program(
  getUserbyIdAPI, // <-aysnc
  pick('commenterID'), // <-sync
  commentSearchAPI, // <-aysnc
  R.head, // <-sync
  R.tap(console.log.bind(console)) // <-sync, logs result to console
);

// these each return a promise resolved with a user's latest comment based on a userID
getUserCommentsbyId(345);

dtipson

//alternatively, creating a custom reduce operation that explicitly wraps the accumulator, then gets curried
const pipePromise2 = R.curry( 
  (list,acc) => list.reduce( (acc,fn) => acc.then(fn), Promise.resolve(acc) ) 
);
//then, since we made our own reduce with the arguments how we wanted them, no need to R.flip
const program = R.compose( pipePromise2, R.unapply(R.flatten) );

dtipson

//using R.useWith to transform the arguments passed to pipePromise
const pipePromisePlus = R.useWith(pipePromise, [acc => Promise.resolve(acc), R.identity]);
const program = R.compose( R.flip(pipePromisePlus), R.unapply(R.flatten) );

dtipson

getUserCommentsbyId = program(
  getUserbyIdAPI, // <-aysnc
  pick('commenterID'), // <-sync
  commentSearchAPI, // <-aysnc
  R.head, // <-sync
  R.tap(console.log.bind(console)) // <-sync, logs result to console
);


//these each return a promise resolved with a user's latest comment based on userID

dtipson

var reduce = fn => Arr => acc => Arr.reduce(fn, acc);

var add = reduce((acc,x)=>acc+x);// -> fn

add123From = add([1,2,3]);// -> fn

add123From(0);// -> 6

dtipson

var reduce = function(fn){
  return function(Arr, acc){
    return Arr.reduce(fn,acc);
  }
}

var add = reduce(function(acc, x){
  return acc+x; 
});

dtipson

var reduce = fn => (Arr, acc) => Arr.reduce(fn, acc);

var add = reduce((acc,x)=>acc+x);

add([1,2,3],0);// -> 6