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Flow vs. flowRight vs. method chaining


#1

@robwise gets credit for this tip:

/* 
   what is a good example that shows when to method chain vs. 
   using flowRight (single line) and flow (multiple lines)?
*/

// the only difference between flow and flowRight is order of invocation.
// flow starts by invoking the function on the left, flowRight starts by
// invoking the function on the right.
// You can use either with both single lines and multiple lines. 
//
// Calling it "flowRight" loses meaning when splitting onto multiple lines
// since it's really like "flowBottom". Alex uses `flowRight` for HOC
// composition because HoCs wrap themselves above the BaseComponent, so
// it just is easier to read that way. BTW, `_.flowRight` is an alias for
// `_.compose` in lodash/fp (to make the transition from Ramda easier).

const people = [{ name: 'bob' }, { name: 'alice' }];

const flowExample = _.flow(_.map(_.get('name')), _.first);
const flowRightExample = _.flowRight(_.first, _.map(_.get('name')));

console.log("flow example");
console.log(flowExample(people));

console.log("flowRight example");
console.log(flowRightExample(people));

// I rarely use method chaining:
// 
// It also forces me to have the data available up front, as opposed to 
// something I can put in a lib (although you can get around that too,
// but why bother?)
// 
// Not point-free, so if you get used to this style of FP you will be lost
// in some other FP languages
const firstName = 
  _(people)
    .map(_.get('name'))
    .first();
    
console.log("chaining example")    
console.log(firstName);