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Editing File: /usr/share/nodejs/lodash.debounce/index.js

/**
 * Lodash (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o packages`
 * Copyright OpenJS Foundation and other contributors <https://openjsf.org/>
 * Released under MIT license <https://lodash.com/license>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 */

/** Error message constants. */
var FUNC_ERROR_TEXT = 'Expected a function';

/** Used as references for various `Number` constants. */
var NAN = 0 / 0;

/** `Object#toString` result references. */
var nullTag = '[object Null]',
    symbolTag = '[object Symbol]',
    undefinedTag = '[object Undefined]';

/** Used to match leading whitespace. */
var reTrimStart = /^\s+/;

/** Used to match a single whitespace character. */
var reWhitespace = /\s/;

/** Used to detect bad signed hexadecimal string values. */
var reIsBadHex = /^[-+]0x[0-9a-f]+$/i;

/** Used to detect binary string values. */
var reIsBinary = /^0b[01]+$/i;

/** Used to detect octal string values. */
var reIsOctal = /^0o[0-7]+$/i;

/** Built-in method references without a dependency on `root`. */
var freeParseInt = parseInt;

/** Detect free variable `global` from Node.js. */
var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;

/** Detect free variable `globalThis` */
const freeGlobalThis = typeof globalThis == 'object' && globalThis !== null && globalThis.Object == Object && globalThis;

/** Detect free variable `self`. */
var freeSelf = typeof self == 'object' && self && self.Object === Object && self;

/** Used as a reference to the global object. */
var root = freeGlobalThis || freeGlobal || freeSelf || Function('return this')();

/**
 * The base implementation of `_.trim`.
 *
 * @private
 * @param {string} string The string to trim.
 * @returns {string} Returns the trimmed string.
 */
function baseTrim(string) {
  return string
    ? string.slice(0, trimmedEndIndex(string) + 1).replace(reTrimStart, '')
    : string;
}

/**
 * Used by `_.trim` and `_.trimEnd` to get the index of the last non-whitespace
 * character of `string`.
 *
 * @private
 * @param {string} string The string to inspect.
 * @returns {number} Returns the index of the last non-whitespace character.
 */
function trimmedEndIndex(string) {
  var index = string.length;

while (index-- && reWhitespace.test(string.charAt(index))) {}
  return index;
}

/** Used for built-in method references. */
var objectProto = Object.prototype;

/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;

/**
 * Used to resolve the
 * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
 * of values.
 */
var nativeObjectToString = objectProto.toString;

/** Built-in value references. */
var Symbol = root.Symbol,
    symToStringTag = Symbol ? Symbol.toStringTag : undefined;

/* Built-in method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max,
    nativeMin = Math.min;

/**
 * The base implementation of `getTag` without fallbacks for buggy environments.
 *
 * @private
 * @param {*} value The value to query.
 * @returns {string} Returns the `toStringTag`.
 */
function baseGetTag(value) {
  if (value == null) {
    return value === undefined ? undefinedTag : nullTag;
  }
  return (symToStringTag && symToStringTag in Object(value))
    ? getRawTag(value)
    : objectToString(value);
}

/**
 * A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
 *
 * @private
 * @param {*} value The value to query.
 * @returns {string} Returns the raw `toStringTag`.
 */
function getRawTag(value) {
  var isOwn = hasOwnProperty.call(value, symToStringTag),
      tag = value[symToStringTag];

try {
    value[symToStringTag] = undefined;
    var unmasked = true;
  } catch (e) {}

var result = nativeObjectToString.call(value);
  if (unmasked) {
    if (isOwn) {
      value[symToStringTag] = tag;
    } else {
      delete value[symToStringTag];
    }
  }
  return result;
}

/**
 * Converts `value` to a string using `Object.prototype.toString`.
 *
 * @private
 * @param {*} value The value to convert.
 * @returns {string} Returns the converted string.
 */
function objectToString(value) {
  return nativeObjectToString.call(value);
}

/**
 * Gets the timestamp of the number of milliseconds that have elapsed since
 * the Unix epoch (1 January 1970 00:00:00 UTC).
 *
 * @static
 * @memberOf _
 * @since 2.4.0
 * @category Date
 * @returns {number} Returns the timestamp.
 * @example
 *
 * _.defer(function(stamp) {
 *   console.log(_.now() - stamp);
 * }, _.now());
 * // => Logs the number of milliseconds it took for the deferred invocation.
 */
var now = function() {
  return root.Date.now();
};

/**
 * Creates a debounced function that delays invoking `func` until after `wait`
 * milliseconds have elapsed since the last time the debounced function was
 * invoked. The debounced function comes with a `cancel` method to cancel
 * delayed `func` invocations and a `flush` method to immediately invoke them.
 * Provide `options` to indicate whether `func` should be invoked on the
 * leading and/or trailing edge of the `wait` timeout. The `func` is invoked
 * with the last arguments provided to the debounced function. Subsequent
 * calls to the debounced function return the result of the last `func`
 * invocation.
 *
 * **Note:** If `leading` and `trailing` options are `true`, `func` is
 * invoked on the trailing edge of the timeout only if the debounced function
 * is invoked more than once during the `wait` timeout.
 *
 * If `wait` is `0` and `leading` is `false`, `func` invocation is deferred
 * until to the next tick, similar to `setTimeout` with a timeout of `0`.
 *
 * See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/)
 * for details over the differences between `_.debounce` and `_.throttle`.
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @category Function
 * @param {Function} func The function to debounce.
 * @param {number} [wait=0] The number of milliseconds to delay.
 * @param {Object} [options={}] The options object.
 * @param {boolean} [options.leading=false]
 *  Specify invoking on the leading edge of the timeout.
 * @param {number} [options.maxWait]
 *  The maximum time `func` is allowed to be delayed before it's invoked.
 * @param {boolean} [options.trailing=true]
 *  Specify invoking on the trailing edge of the timeout.
 * @returns {Function} Returns the new debounced function.
 * @example
 *
 * // Avoid costly calculations while the window size is in flux.
 * jQuery(window).on('resize', _.debounce(calculateLayout, 150));
 *
 * // Invoke `sendMail` when clicked, debouncing subsequent calls.
 * jQuery(element).on('click', _.debounce(sendMail, 300, {
 *   'leading': true,
 *   'trailing': false
 * }));
 *
 * // Ensure `batchLog` is invoked once after 1 second of debounced calls.
 * var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
 * var source = new EventSource('/stream');
 * jQuery(source).on('message', debounced);
 *
 * // Cancel the trailing debounced invocation.
 * jQuery(window).on('popstate', debounced.cancel);
 */
function debounce(func, wait, options) {
  var lastArgs,
      lastThis,
      maxWait,
      result,
      timerId,
      lastCallTime,
      lastInvokeTime = 0,
      leading = false,
      maxing = false,
      trailing = true;

if (typeof func != 'function') {
    throw new TypeError(FUNC_ERROR_TEXT);
  }
  wait = toNumber(wait) || 0;
  if (isObject(options)) {
    leading = !!options.leading;
    maxing = 'maxWait' in options;
    maxWait = maxing ? nativeMax(toNumber(options.maxWait) || 0, wait) : maxWait;
    trailing = 'trailing' in options ? !!options.trailing : trailing;
  }

function invokeFunc(time) {
    var args = lastArgs,
        thisArg = lastThis;

lastArgs = lastThis = undefined;
    lastInvokeTime = time;
    result = func.apply(thisArg, args);
    return result;
  }

function leadingEdge(time) {
    // Reset any `maxWait` timer.
    lastInvokeTime = time;
    // Start the timer for the trailing edge.
    timerId = setTimeout(timerExpired, wait);
    // Invoke the leading edge.
    return leading ? invokeFunc(time) : result;
  }

function remainingWait(time) {
    var timeSinceLastCall = time - lastCallTime,
        timeSinceLastInvoke = time - lastInvokeTime,
        timeWaiting = wait - timeSinceLastCall;

return maxing
      ? nativeMin(timeWaiting, maxWait - timeSinceLastInvoke)
      : timeWaiting;
  }

function shouldInvoke(time) {
    var timeSinceLastCall = time - lastCallTime,
        timeSinceLastInvoke = time - lastInvokeTime;

// Either this is the first call, activity has stopped and we're at the
    // trailing edge, the system time has gone backwards and we're treating
    // it as the trailing edge, or we've hit the `maxWait` limit.
    return (lastCallTime === undefined || (timeSinceLastCall >= wait) ||
      (timeSinceLastCall < 0) || (maxing && timeSinceLastInvoke >= maxWait));
  }

function timerExpired() {
    var time = now();
    if (shouldInvoke(time)) {
      return trailingEdge(time);
    }
    // Restart the timer.
    timerId = setTimeout(timerExpired, remainingWait(time));
  }

function trailingEdge(time) {
    timerId = undefined;

// Only invoke if we have `lastArgs` which means `func` has been
    // debounced at least once.
    if (trailing && lastArgs) {
      return invokeFunc(time);
    }
    lastArgs = lastThis = undefined;
    return result;
  }

function cancel() {
    if (timerId !== undefined) {
      clearTimeout(timerId);
    }
    lastInvokeTime = 0;
    lastArgs = lastCallTime = lastThis = timerId = undefined;
  }

function flush() {
    return timerId === undefined ? result : trailingEdge(now());
  }

function debounced() {
    var time = now(),
        isInvoking = shouldInvoke(time);

lastArgs = arguments;
    lastThis = this;
    lastCallTime = time;

if (isInvoking) {
      if (timerId === undefined) {
        return leadingEdge(lastCallTime);
      }
      if (maxing) {
        // Handle invocations in a tight loop.
        clearTimeout(timerId);
        timerId = setTimeout(timerExpired, wait);
        return invokeFunc(lastCallTime);
      }
    }
    if (timerId === undefined) {
      timerId = setTimeout(timerExpired, wait);
    }
    return result;
  }
  debounced.cancel = cancel;
  debounced.flush = flush;
  return debounced;
}

/**
 * Checks if `value` is the
 * [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
 * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @since 0.1.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an object, else `false`.
 * @example
 *
 * _.isObject({});
 * // => true
 *
 * _.isObject([1, 2, 3]);
 * // => true
 *
 * _.isObject(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return value != null && (type == 'object' || type == 'function');
}

/**
 * Checks if `value` is object-like. A value is object-like if it's not `null`
 * and has a `typeof` result of "object".
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
 * @example
 *
 * _.isObjectLike({});
 * // => true
 *
 * _.isObjectLike([1, 2, 3]);
 * // => true
 *
 * _.isObjectLike(_.noop);
 * // => false
 *
 * _.isObjectLike(null);
 * // => false
 */
function isObjectLike(value) {
  return value != null && typeof value == 'object';
}

/**
 * Checks if `value` is classified as a `Symbol` primitive or object.
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a symbol, else `false`.
 * @example
 *
 * _.isSymbol(Symbol.iterator);
 * // => true
 *
 * _.isSymbol('abc');
 * // => false
 */
function isSymbol(value) {
  return typeof value == 'symbol' ||
    (isObjectLike(value) && baseGetTag(value) == symbolTag);
}

/**
 * Converts `value` to a number.
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to process.
 * @returns {number} Returns the number.
 * @example
 *
 * _.toNumber(3.2);
 * // => 3.2
 *
 * _.toNumber(Number.MIN_VALUE);
 * // => 5e-324
 *
 * _.toNumber(Infinity);
 * // => Infinity
 *
 * _.toNumber('3.2');
 * // => 3.2
 */
function toNumber(value) {
  if (typeof value == 'number') {
    return value;
  }
  if (isSymbol(value)) {
    return NAN;
  }
  if (isObject(value)) {
    var other = typeof value.valueOf == 'function' ? value.valueOf() : value;
    value = isObject(other) ? (other + '') : other;
  }
  if (typeof value != 'string') {
    return value === 0 ? value : +value;
  }
  value = baseTrim(value);
  var isBinary = reIsBinary.test(value);
  return (isBinary || reIsOctal.test(value))
    ? freeParseInt(value.slice(2), isBinary ? 2 : 8)
    : (reIsBadHex.test(value) ? NAN : +value);
}

module.exports = debounce;

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