Nodejs Array Concatenate Map concatMap(f)

Method Source Code

'use strict';//  www .  ja  v  a 2  s  .co  m

let j = require('junify');

Array.prototype.concatMap = function (f) {
  return Array.prototype.concat.apply([], this.map(f));
};

j.matchesAny = function (patterns) {
  return (it) => patterns.some(pattern => j.unify(pattern, it));
};

j.match = function (arg, cases) {
  for (let i = 0; i < cases.length; i++) {
    let patternAndCallback = cases[i];
    let pattern = patternAndCallback[0];
    let callback = patternAndCallback[1];
    let match = j.unify(pattern, arg);
    if (match) {
      return callback(match);
    }
  }
  throw new Error(`Non exhaustive pattern-matching: ${JSON.stringify(arg)}`);
};

j.case = function (pattern, action) {
  return [pattern, action];
};

module.exports = {
  j: j
};

Related

1. concatMap()

   Array.prototype.concatMap = function() {
     return this.map(function(item) {
         return projectionFunction(item);
       }).concatAll();
   };
   

2. concatMap(cb)

   'use strict';
   Array.prototype.concatMap = function (cb) {
       return this.map(cb).concatAll()
   

3. concatMap(f)

   'use strict';
   var j = require('junify');
   Array.prototype.concatMap = function (f) {
     return Array.prototype.concat.apply([], this.map(f));
   };
   j.matchesAny = function (patterns) {
     return function (it) {
       return patterns.some(function (pattern) {
         return  j.unify(pattern, it);
   ...
   

4. concatMap(fn)

   Array.prototype.concatMap = function(fn) {
       return this
           .map((item, index, arr) => fn(index))
           .concatAll();
   };
   

5. concatMap(modifierFunction)

   Array.prototype.concatMap = function (modifierFunction) {
       return this.map(modifierFunction).concatAll();
   

6. concatMap(projectionFunction)

   Array.prototype.concatMap = function(projectionFunction){
     return this.map(function(item){
       return projectionFunction(item);
     }).concatAll();
   

7. concatMap(projectionFunctionThatReturnsArray)

   Array.prototype.concatMap = function (projectionFunctionThatReturnsArray) {
     return this.
       map(function (item) {
         return projectionFunctionThatReturnsArray(item);
       }).
       concatAll();
   };