lambda-math

Lambda math

Pseudo lambda expressions for JS arbitrary-precision arithmetic operations.

NOTE: Under development. Most of the functionality is still not working.

Example

Consider adding the floating point number 300 / 293 many times. 72 times in fact. Now, we don't want to simply multiply a number by 72. We want to add it 72 times, so that we can clearly see the problem with floating point rounding which exists in standard JavaScript. So, using lambda-math library, we can write:

import { λ, _, add, div } from 'lambda-math';

λ( div, [300, 293] )
 ( add, [λ[0], λ[0]], [_, λ[0]], 70 );

console.log(λ[1].number); // 73.72013651877133

Compare the above to the simple JavaScript way of doing such a sum:

let result = 0;

for (let i = 0; i < 72; i += 1) {
  result += 300 / 293;
}

console.log(result); // 73.72013651877126

Or, a more functional (fancy) JS approach:

console.log(
  Array.from(Array(72).keys()).map(() => { return 300 / 293; }).reduce((a, b) => { return a + b; })
); // 73.72013651877126

As you can see, the pseudo lambda approach doesn't have the problem with rounding floating point numbers. Also, some (mathematicians) can argue that the syntax lambda-math introduces is more elegant, shorter, and cleaner overall (compared to pure JavaScript way of doing things).

Internals

Besides adding pseudo syntactic sugar, lambda-math uses bignumber.js under the hood for actual arbitrary-precision decimal arithmetic.