arextar/LICENSE.txt

## annotated.js
function(
    a, //Lower bound
    b, //Upper bound
    c, //[Step function]
    d, //Multiply
    e,f //Placeholders
){
    c===true&&(d=c,c=0);              //If c is true, use c as the 'multiply' param
    if(a==1&&!c&&!d) return (b*b+b)/2 //If it's a standard summation of 1..n, optimize

    for(
        e=!!d                         //initiate counter as d (will coerce to 0 if adding, 1 if multiplying)
        ;a<=b;                        //While lower bound is less than the upper bound...
            f=c?c(b):b,               //If a step function is passed, use it
            d?e*=f:e+=f,              //Perform the necessary operation
            b--                       //Decrement the upper bound
    );
    return e;                         //Return the result of the summation
}

## index.js
function(a,b,c,d,e,f){c===!0&&(d=c,c=0);if(a==1&&!c&&!d)return(b*b+b)/2;for(e=!!d;a<=b;f=c?c(b):b,d?e*=f:e+=f,b--);return e}

## LICENSE.txt
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

## package.json
{
  "name": "summation",

  "description": "A function to execute a summation in JavaScript. Support for a step function and multiplication",

  "keywords": [
    "math"
  ]
}

## test.html
<!DOCTYPE html>
<title>Summation</title>
<div>Expected value: <b>[5050, 5049, -15, 120]</b></div>
<div>Actual value: <b id="ret"></b></div>
<script>
  var summate = function(a,b,c,d,e,f){c===!0&&(d=c,c=0);if(a==1&&!c&&!d)return(b*b+b)/2;for(e=!!d;a<=b;f=c?c(b):b,d?e*=f:e+=f,b--);return e}


  document.getElementById( "ret" ).innerHTML = "["+[
  summate(1,100),
  summate(2,100),
  summate(1,5,function(n){
    return -n;
  }),
  summate(1,5,true)].join(", ")+"]"
</script>
	function(
	a, //Lower bound
	b, //Upper bound
	c, //[Step function]
	d, //Multiply
	e,f //Placeholders
	){
	c===true&&(d=c,c=0); //If c is true, use c as the 'multiply' param
	if(a==1&&!c&&!d) return (b*b+b)/2 //If it's a standard summation of 1..n, optimize

	for(
	e=!!d //initiate counter as d (will coerce to 0 if adding, 1 if multiplying)
	;a<=b; //While lower bound is less than the upper bound...
	f=c?c(b):b, //If a step function is passed, use it
	d?e*=f:e+=f, //Perform the necessary operation
	b-- //Decrement the upper bound
	);
	return e; //Return the result of the summation
	}
	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	Version 2, December 2004

	Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE>

	Everyone is permitted to copy and distribute verbatim or modified
	copies of this license document, and changing it is allowed as long
	as the name is changed.

	DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
	TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

	0. You just DO WHAT THE FUCK YOU WANT TO.
	{
	"name": "summation",

	"description": "A function to execute a summation in JavaScript. Support for a step function and multiplication",

	"keywords": [
	"math"
	]
	}
	<!DOCTYPE html>
	<title>Summation</title>
	<div>Expected value: <b>[5050, 5049, -15, 120]</b></div>
	<div>Actual value: <b id="ret"></b></div>
	<script>
	var summate = function(a,b,c,d,e,f){c===!0&&(d=c,c=0);if(a==1&&!c&&!d)return(bb+b)/2;for(e=!!d;a<=b;f=c?c(b):b,d?e=f:e+=f,b--);return e}



	document.getElementById( "ret" ).innerHTML = "["+[
	summate(1,100),
	summate(2,100),
	summate(1,5,function(n){
	return -n;
	}),
	summate(1,5,true)].join(", ")+"]"
	</script>