shunting-yard-arbitrary-precision

Arbitrary precision support on top of javascript-shunting-yard, a mathematical expression parser.

Install

npm i shunting-yard-arbitrary-precision

Usage

const shunt = require('shunting-yard-arbitrary-precision');

Number(shunt('3+2')); //=> 5

// all following results are returned as Decimal
// with the floating adapter by default
shunt('3+2'); //=> 5 (as Decimal)
shunt('(10+5)/5'); //=> 3
shunt('3+(5*2)*(-3+2)'); //=> -7
shunt('2^3'); //=> 8

const decimalFactory = require('arbitrary-precision');
const Decimal = decimalFactory(require('bigjs-adapter'));

shunt('0.1+0.2', {Decimal: Decimal}); //=> 0.3

let context = new shunt.Context();

context.def('abs');
shunt('2*abs(-3)', {context: context}); //=> 6

context.def('tau', 2 * Math.PI);
shunt('3*tau', {context: context}); //=> 18.84955592153876

context.def('javier', a => a * 1.618);
shunt('javier(21)', {context: context}); //=> 33.978

Example with Ramda:

const R = require('ramda');
const curriedShunt = R.curryN(2, shunt);
const myShunt = curriedShunt(R.__, {Decimal: Decimal, context: context});

myShunt('javier(abs(-3))*.2'); //=> 0.9708
shunt('(1.618*3)*.2'); //=> 0.9708000000000001

See live example.
See spec.