@neutrium/quantity/dist/operations/clean-unit-names.js

The NeutriumJS unit conversion module.

import { UnitTokenManager } from "../UnitTokenManager.js";
const UNITY = "<1>";
// Cleans up the the units so that they have consistent naming
// e.g. convert ["rad", "radian", "radians"] = ["rad", "rad", "rad"]
export function cleanUnitNames(num, den) {
    const tokenMapper = UnitTokenManager.instance;
    num = num.filter(function (val) { return val !== UNITY; });
    den = den.filter(function (val) { return val !== UNITY; });
    let combined = {}, k;
    for (let i = 0, len = num.length; i < len; i++) {
        let unit = tokenMapper.getUnit(num[i]);
        k = [num[i]];
        if (unit.category === 'prefix') {
            k.push(num[i + 1]);
            i++;
        }
        if (k && k !== UNITY) {
            if (combined[k]) {
                combined[k][0]++;
            }
            else {
                combined[k] = [1, k];
            }
        }
    }
    for (let j = 0; j < den.length; j++) {
        let unit = tokenMapper.getUnit(den[j]);
        k = [den[j]];
        if (unit.category === 'prefix') {
            k.push(den[j + 1]);
            j++;
        }
        if (k && k !== UNITY) {
            if (combined[k]) {
                combined[k][0]--;
            }
            else {
                combined[k] = [-1, k];
            }
        }
    }
    num = [];
    den = [];
    for (let prop in combined) {
        if (combined.hasOwnProperty(prop)) {
            let item = combined[prop], n;
            if (item[0] > 0) {
                for (n = 0; n < item[0]; n++) {
                    num.push(item[1]);
                }
            }
            else if (item[0] < 0) {
                for (n = 0; n < -item[0]; n++) {
                    den.push(item[1]);
                }
            }
        }
    }
    if (num.length === 0) {
        num = [UNITY];
    }
    if (den.length === 0) {
        den = [UNITY];
    }
    // Flatten
    num = num.reduce(function (a, b) {
        return a.concat(b);
    }, []);
    den = den.reduce(function (a, b) {
        return a.concat(b);
    }, []);
    return [num, den];
}