chronos.js

// chronos.js
// version : 0.1.0
// author : Enrico Spinielli
// license : MIT
// chronosjs.com

(function(_) {

   var BOGUS = "bogus";

   function quotient(m, n) {
      return Math.floor(m / n);
   };

   function mod(a, b) {
      return a - (b * quotient(a, b));
   };

   function amod(a, b) {
      return b + mod(a, -b);
   };

   function next(index, predicate) {
      if (predicate(index)) {
         return index;
      }
      else {
         return next(index + 1, predicate);
      }
   };

   function final(index, predicate) {
      if (! predicate(index)) {
         return index - 1;
      }
      else {
         return final(index + 1, predicate);
      }
   };

   function sum(expression, index, predicate) {
      if (! predicate(index)) {
         return 0;
      }
      else {
         return expression(index) + sum(expression, index + 1, predicate);
      }
   };

   function binary_search(low, high, dir, condition) {
      var mid = (low + high) / 2;
      if (dir(low, high)) {
         return mid;
      }
      else if (condition(mid)) {
         return binary_search(low, mid, dir, condition);
      }
      else {
         return binary_search(mid, high, dir, condition);
      }
   };

   function invert_angular(func, y, low, high) {
      var precision = Math.pow(10, -5);
      return binary_search(low, high,
         function(l, h) {return (h - l) <= precision;},
         function(x) {return mod(func(x) - y, 360) < 180;});
   };

   /************************************
   Exposing Chronos
   ************************************/
   // CommonJS module is defined
   // check for nodeJS
   var  hasModule = (typeof module !== 'undefined' && module.exports);
   if (hasModule) {
      module.exports = chronos;
   }
   /*global ender:false */
   if (typeof ender === 'undefined') {
   // here, `this` means `window` in the browser, or `global` on the server
   // add `chronos` as a global object via a string identifier,
   // for Closure Compiler "advanced" mode
   this['chronos'] = chronos;
   }
   /*global define:false */
   if (typeof define === "function" && define.amd) {
      define("chronos", [], function () {
         return chronos;
      });
   }

   chronos.version = "0.0.1";
   chronos.quotient = quotient;
   chronos.mod = mod;
   chronos.amod = amod;
   chronos.next = next;
   chronos.final = final;
   chronos.sum = sum;
   chronos.binary_search = binary_search;
   _.chronos = chronos;
})(this);