meows/build/time.js

A kittybin of tools.

"use strict";
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// Date and Time
Object.defineProperty(exports, "__esModule", { value: true });
/**
 * Convert an integer from 1 to 12 to a month.
 * @example
 * numberToMonth(1)   // => January
 * numberToMonth(12)  // => December
 */
function numberToMonth(int) {
    if (int <= 0 || 12 < int || !Number.isSafeInteger(int)) {
        throw new TypeError(`number_to_month() requires an integer between 1 to 12, but received: ${int}.`);
    }
    return { 1: 'January',
        2: 'February',
        3: 'March',
        4: 'April',
        5: 'May',
        6: 'June',
        7: 'July',
        8: 'August',
        9: 'September',
        10: 'October',
        11: 'November',
        12: 'December', }[int];
}
exports.numberToMonth = numberToMonth;
/** A utility to store multiple timestamps for performance timing.
 * @example
 * const timer = new Timer()
 * timer.start('fetch starts')
 * timer.next('fetch resolved')
 * timer.end('awaiting done')
 */
class Timer {
    constructor() {
        /** The full state of the Timer object. */
        this._log = [];
        /** A list of Unix timestamps. */
        this._times = () => this._log.map(x => x.time);
        /** Add a midpoint to timer with optional label. */
        this.next = (label = 'NEXT') => this._log.push({ label, time: Date.now() });
        /** Start timer with optional label. */
        this.start = (label = 'START') => this.next(label);
        /** Add endpoint to timer with optional label. */
        this.end = (label = 'END') => this.next(label);
        /** range :: () → [integer tF - t0] || NaN if fewer than 2 timestamps */
        this.range = (arr = this._log) => arr.length > 1
            ? arr[arr.length - 1].time - arr[0].time
            : NaN;
        /** delta :: () → [ integer list of velocities ] || [] if fewer than 2 timestamps */
        this.delta = ([head, ...tail] = this._times()) => this._log.length
            ? this._times()
                .reduce((state, n, i, arr) => state.concat(n - arr[i - 1]), [])
                .slice(1)
            : [];
        /** Returns array of relative difference of time from start, with head as initial timestamp. */
        this.relative = ([head, ...tail] = this._times()) => this._log.length
            ? tail.reduce((state, n) => state.concat(n - head), [head])
            : [];
    }
}
exports.Timer = Timer;