Implement grains after TS gains int Type

[masters3d]

Grains needs a BigInt Library http://www.2ality.com/2015/04/numbers-math-es6.html

microsoft/TypeScript#4639 (comment)

/**
 * In JavaScript, integers beyond +/- 9007199254740991 cannot be accurately
 * represented. To see this in action, console.log() out the expected number
 * of grains on square #64:
 *
 * console.log(9223372036854775808);
 * // =>       9223372036854776000
 * //                         ^^^^
 *
 * This is because, in JavaScript, integers are represented as 64-bit floating
 * point numbers. If you want to learn more, see:
 *
 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER
 * http://stackoverflow.com/questions/307179/what-is-javascripts-highest-integer-value-that-a-number-can-go-to-without-losin
 *
 * So, an accurate solution to this problem requires the use of a
 * "big integer" type. There are multiple ways to use big integer types.
 * We have provided you with BigInteger.js. You can read more about it here:
 *
 * https://github.com/peterolson/BigInteger.js
 * ^--- The "Methods" section of the README will be especially helpful.
 *
 * https://github.com/peterolson/BigInteger.js/blob/master/spec/spec.js
 * ^--- Tests are a good way to understand, in addition to the README.
 *
 * To get you started, this folder has a file of the big-integer module.
 * See its tests in this folder for a quick primer on how to use it! ( :
 */

[masters3d]

BigInt is at stage 3, log time coming.
https://github.com/tc39/proposal-bigint

[masters3d]

its here
https://twitter.com/typescriptlang/status/1068250524108042240

[joshiraez]

I'll take a look at this