JavaScript: Functional Programming for JavaScript Developers

Appendix A. Common Functions for Functional Programming in JavaScript

This Appendix covers common functions for functional programming in JavaScript:

• Array Functions:

  var flatten = function(arrays) {
    return arrays.reduce( function(p,n){
      return p.concat(n);
    });
  };
  
  var invert = function(arr) {
    return arr.map(function(x, i, a) {
      return a[a.length - (i+1)];
    });
  };

• Binding Functions:

  var bind = Function.prototype.call.bind(Function.prototype.bind);
  var call = bind(Function.prototype.call, Function.prototype.call);
  var apply = bind(Function.prototype.call, Function.prototype.apply);

• Category Theory:

  var checkTypes = function( typeSafeties ) { arrayOf(func)(arr(typeSafeties)); var argLength = typeSafeties.length; return function(args) { arr(args); if (args.length ...