wip: migrate to bun

src/.eslintrc.cjs

@@ -0,0 +1,18 @@
+'use strict';
+
+const path = require('node:path');
+
+module.exports = {
+    overrides: [
+        {
+            files: ['**/*.{ts}'],
+            rules: {
+                'import/no-extraneous-dependencies': [
+                    'error',
+                    // Use package.json from both this package folder and root.
+                    { packageDir: [__dirname, path.join(__dirname, '../')] },
+                ],
+            },
+        },
+    ],
+};

src/.internal/Hash.ts

@@ -0,0 +1,88 @@
+/** Used to stand-in for `undefined` hash values. */
+const HASH_UNDEFINED = '__lodash_hash_undefined__'
+
+class Hash {
+
+  /**
+   * Creates a hash object.
+   *
+   * @private
+   * @constructor
+   * @param {Array} [entries] The key-value pairs to cache.
+   */
+  constructor(entries) {
+    let index = -1
+    const length = entries == null ? 0 : entries.length
+
+    this.clear()
+    while (++index < length) {
+      const entry = entries[index]
+      this.set(entry[0], entry[1])
+    }
+  }
+
+  /**
+   * Removes all key-value entries from the hash.
+   *
+   * @memberOf Hash
+   */
+  clear() {
+    this.__data__ = Object.create(null)
+    this.size = 0
+  }
+
+  /**
+   * Removes `key` and its value from the hash.
+   *
+   * @memberOf Hash
+   * @param {string} key The key of the value to remove.
+   * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+   */
+  delete(key) {
+    const result = this.has(key) && delete this.__data__[key]
+    this.size -= result ? 1 : 0
+    return result
+  }
+
+  /**
+   * Gets the hash value for `key`.
+   *
+   * @memberOf Hash
+   * @param {string} key The key of the value to get.
+   * @returns {*} Returns the entry value.
+   */
+  get(key) {
+    const data = this.__data__
+    const result = data[key]
+    return result === HASH_UNDEFINED ? undefined : result
+  }
+
+  /**
+   * Checks if a hash value for `key` exists.
+   *
+   * @memberOf Hash
+   * @param {string} key The key of the entry to check.
+   * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+   */
+  has(key) {
+    const data = this.__data__
+    return data[key] !== undefined
+  }
+
+  /**
+   * Sets the hash `key` to `value`.
+   *
+   * @memberOf Hash
+   * @param {string} key The key of the value to set.
+   * @param {*} value The value to set.
+   * @returns {Object} Returns the hash instance.
+   */
+  set(key, value) {
+    const data = this.__data__
+    this.size += this.has(key) ? 0 : 1
+    data[key] = value === undefined ? HASH_UNDEFINED : value
+    return this
+  }
+}
+
+export default Hash

src/.internal/ListCache.ts

@@ -0,0 +1,103 @@
+import assocIndexOf from './assocIndexOf.js'
+
+class ListCache {
+
+  /**
+   * Creates an list cache object.
+   *
+   * @private
+   * @constructor
+   * @param {Array} [entries] The key-value pairs to cache.
+   */
+  constructor(entries) {
+    let index = -1
+    const length = entries == null ? 0 : entries.length
+
+    this.clear()
+    while (++index < length) {
+      const entry = entries[index]
+      this.set(entry[0], entry[1])
+    }
+  }
+
+  /**
+   * Removes all key-value entries from the list cache.
+   *
+   * @memberOf ListCache
+   */
+  clear() {
+    this.__data__ = []
+    this.size = 0
+  }
+
+  /**
+   * Removes `key` and its value from the list cache.
+   *
+   * @memberOf ListCache
+   * @param {string} key The key of the value to remove.
+   * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+   */
+  delete(key) {
+    const data = this.__data__
+    const index = assocIndexOf(data, key)
+
+    if (index < 0) {
+      return false
+    }
+    const lastIndex = data.length - 1
+    if (index == lastIndex) {
+      data.pop()
+    } else {
+      data.splice(index, 1)
+    }
+    --this.size
+    return true
+  }
+
+  /**
+   * Gets the list cache value for `key`.
+   *
+   * @memberOf ListCache
+   * @param {string} key The key of the value to get.
+   * @returns {*} Returns the entry value.
+   */
+  get(key) {
+    const data = this.__data__
+    const index = assocIndexOf(data, key)
+    return index < 0 ? undefined : data[index][1]
+  }
+
+  /**
+   * Checks if a list cache value for `key` exists.
+   *
+   * @memberOf ListCache
+   * @param {string} key The key of the entry to check.
+   * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+   */
+  has(key) {
+    return assocIndexOf(this.__data__, key) > -1
+  }
+
+  /**
+   * Sets the list cache `key` to `value`.
+   *
+   * @memberOf ListCache
+   * @param {string} key The key of the value to set.
+   * @param {*} value The value to set.
+   * @returns {Object} Returns the list cache instance.
+   */
+  set(key, value) {
+    const data = this.__data__
+    const index = assocIndexOf(data, key)
+
+    if (index < 0) {
+      ++this.size
+      data.push([key, value])
+    } else {
+      data[index][1] = value
+    }
+    return this
+  }
+}
+
+export default ListCache

src/.internal/MapCache.ts

@@ -0,0 +1,120 @@
+
+import Hash from './Hash.js'
+
+/**
+ * Gets the data for `map`.
+ *
+ * @private
+ * @param {Object} map The map to query.
+ * @param {string} key The reference key.
+ * @returns {*} Returns the map data.
+ */
+function getMapData({ __data__ }, key) {
+  const data = __data__
+  return isKeyable(key)
+    ? data[typeof key === 'string' ? 'string' : 'hash']
+    : data.map
+}
+
+/**
+ * Checks if `value` is suitable for use as unique object key.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is suitable, else `false`.
+ */
+function isKeyable(value) {
+  const type = typeof value
+  return (type === 'string' || type === 'number' || type === 'symbol' || type === 'boolean')
+    ? (value !== '__proto__')
+    : (value === null)
+}
+
+class MapCache {
+
+  /**
+   * Creates a map cache object to store key-value pairs.
+   *
+   * @private
+   * @constructor
+   * @param {Array} [entries] The key-value pairs to cache.
+   */
+  constructor(entries) {
+    let index = -1
+    const length = entries == null ? 0 : entries.length
+
+    this.clear()
+    while (++index < length) {
+      const entry = entries[index]
+      this.set(entry[0], entry[1])
+    }
+  }
+
+  /**
+   * Removes all key-value entries from the map.
+   *
+   * @memberOf MapCache
+   */
+  clear() {
+    this.size = 0
+    this.__data__ = {
+      'hash': new Hash,
+      'map': new Map,
+      'string': new Hash
+    }
+  }
+
+  /**
+   * Removes `key` and its value from the map.
+   *
+   * @memberOf MapCache
+   * @param {string} key The key of the value to remove.
+   * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+   */
+  delete(key) {
+    const result = getMapData(this, key)['delete'](key)
+    this.size -= result ? 1 : 0
+    return result
+  }
+
+  /**
+   * Gets the map value for `key`.
+   *
+   * @memberOf MapCache
+   * @param {string} key The key of the value to get.
+   * @returns {*} Returns the entry value.
+   */
+  get(key) {
+    return getMapData(this, key).get(key)
+  }
+
+  /**
+   * Checks if a map value for `key` exists.
+   *
+   * @memberOf MapCache
+   * @param {string} key The key of the entry to check.
+   * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+   */
+  has(key) {
+    return getMapData(this, key).has(key)
+  }
+
+  /**
+   * Sets the map `key` to `value`.
+   *
+   * @memberOf MapCache
+   * @param {string} key The key of the value to set.
+   * @param {*} value The value to set.
+   * @returns {Object} Returns the map cache instance.
+   */
+  set(key, value) {
+    const data = getMapData(this, key)
+    const size = data.size
+
+    data.set(key, value)
+    this.size += data.size == size ? 0 : 1
+    return this
+  }
+}
+
+export default MapCache

src/.internal/SetCache.ts

@@ -0,0 +1,52 @@
+import MapCache from './MapCache.js'
+
+/** Used to stand-in for `undefined` hash values. */
+const HASH_UNDEFINED = '__lodash_hash_undefined__'
+
+class SetCache {
+
+  /**
+   * Creates an array cache object to store unique values.
+   *
+   * @private
+   * @constructor
+   * @param {Array} [values] The values to cache.
+   */
+  constructor(values) {
+    let index = -1
+    const length = values == null ? 0 : values.length
+
+    this.__data__ = new MapCache
+    while (++index < length) {
+      this.add(values[index])
+    }
+  }
+
+  /**
+   * Adds `value` to the array cache.
+   *
+   * @memberOf SetCache
+   * @alias push
+   * @param {*} value The value to cache.
+   * @returns {Object} Returns the cache instance.
+   */
+  add(value) {
+    this.__data__.set(value, HASH_UNDEFINED)
+    return this
+  }
+
+  /**
+   * Checks if `value` is in the array cache.
+   *
+   * @memberOf SetCache
+   * @param {*} value The value to search for.
+   * @returns {boolean} Returns `true` if `value` is found, else `false`.
+   */
+  has(value) {
+    return this.__data__.has(value)
+  }
+}
+
+SetCache.prototype.push = SetCache.prototype.add
+
+export default SetCache

src/.internal/Stack.ts

@@ -0,0 +1,93 @@
+import ListCache from './ListCache.js'
+import MapCache from './MapCache.js'
+
+/** Used as the size to enable large array optimizations. */
+const LARGE_ARRAY_SIZE = 200
+
+class Stack {
+
+  /**
+   * Creates a stack cache object to store key-value pairs.
+   *
+   * @private
+   * @constructor
+   * @param {Array} [entries] The key-value pairs to cache.
+   */
+  constructor(entries) {
+    const data = this.__data__ = new ListCache(entries)
+    this.size = data.size
+  }
+
+  /**
+   * Removes all key-value entries from the stack.
+   *
+   * @memberOf Stack
+   */
+  clear() {
+    this.__data__ = new ListCache
+    this.size = 0
+  }
+
+  /**
+   * Removes `key` and its value from the stack.
+   *
+   * @memberOf Stack
+   * @param {string} key The key of the value to remove.
+   * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+   */
+  delete(key) {
+    const data = this.__data__
+    const result = data['delete'](key)
+
+    this.size = data.size
+    return result
+  }
+
+  /**
+   * Gets the stack value for `key`.
+   *
+   * @memberOf Stack
+   * @param {string} key The key of the value to get.
+   * @returns {*} Returns the entry value.
+   */
+  get(key) {
+    return this.__data__.get(key)
+  }
+
+  /**
+   * Checks if a stack value for `key` exists.
+   *
+   * @memberOf Stack
+   * @param {string} key The key of the entry to check.
+   * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+   */
+  has(key) {
+    return this.__data__.has(key)
+  }
+
+  /**
+   * Sets the stack `key` to `value`.
+   *
+   * @memberOf Stack
+   * @param {string} key The key of the value to set.
+   * @param {*} value The value to set.
+   * @returns {Object} Returns the stack cache instance.
+   */
+  set(key, value) {
+    let data = this.__data__
+    if (data instanceof ListCache) {
+      const pairs = data.__data__
+      if (pairs.length < LARGE_ARRAY_SIZE - 1) {
+        pairs.push([key, value])
+        this.size = ++data.size
+        return this
+      }
+      data = this.__data__ = new MapCache(pairs)
+    }
+    data.set(key, value)
+    this.size = data.size
+    return this
+  }
+}
+
+export default Stack

src/.internal/addMapEntry.ts

@@ -0,0 +1,15 @@
+/**
+ * Adds the key-value `pair` to `map`.
+ *
+ * @private
+ * @param {Object} map The map to modify.
+ * @param {Array} pair The key-value pair to add.
+ * @returns {Object} Returns `map`.
+ */
+function addMapEntry(map, pair) {
+  // Don't return `map.set` because it's not chainable in IE 11.
+  map.set(pair[0], pair[1])
+  return map
+}
+
+export default addMapEntry

src/.internal/addSetEntry.ts

@@ -0,0 +1,15 @@
+/**
+ * Adds `value` to `set`.
+ *
+ * @private
+ * @param {Object} set The set to modify.
+ * @param {*} value The value to add.
+ * @returns {Object} Returns `set`.
+ */
+function addSetEntry(set, value) {
+  // Don't return `set.add` because it's not chainable in IE 11.
+  set.add(value)
+  return set
+}
+
+export default addSetEntry

src/.internal/arrayEach.ts

@@ -0,0 +1,21 @@
+/**
+ * A specialized version of `forEach` for arrays.
+ *
+ * @private
+ * @param {Array} [array] The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Array} Returns `array`.
+ */
+function arrayEach(array, iteratee) {
+  let index = -1
+  const length = array.length
+
+  while (++index < length) {
+    if (iteratee(array[index], index, array) === false) {
+      break
+    }
+  }
+  return array
+}
+
+export default arrayEach

src/.internal/arrayEachRight.ts

@@ -0,0 +1,20 @@
+/**
+ * A specialized version of `forEachRight` for arrays.
+ *
+ * @private
+ * @param {Array} [array] The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Array} Returns `array`.
+ */
+function arrayEachRight(array, iteratee) {
+  let length = array == null ? 0 : array.length
+
+  while (length--) {
+    if (iteratee(array[length], length, array) === false) {
+      break
+    }
+  }
+  return array
+}
+
+export default arrayEachRight

src/.internal/arrayIncludes.ts

@@ -0,0 +1,17 @@
+import baseIndexOf from './baseIndexOf.js'
+
+/**
+ * A specialized version of `includes` for arrays without support for
+ * specifying an index to search from.
+ *
+ * @private
+ * @param {Array} [array] The array to inspect.
+ * @param {*} target The value to search for.
+ * @returns {boolean} Returns `true` if `target` is found, else `false`.
+ */
+function arrayIncludes(array, value) {
+  const length = array == null ? 0 : array.length
+  return !!length && baseIndexOf(array, value, 0) > -1
+}
+
+export default arrayIncludes

src/.internal/arrayIncludesWith.ts

@@ -0,0 +1,23 @@
+/**
+ * This function is like `arrayIncludes` except that it accepts a comparator.
+ *
+ * @private
+ * @param {Array} [array] The array to inspect.
+ * @param {*} target The value to search for.
+ * @param {Function} comparator The comparator invoked per element.
+ * @returns {boolean} Returns `true` if `target` is found, else `false`.
+ */
+function arrayIncludesWith(array, target, comparator) {
+  if (array == null) {
+    return false
+  }
+
+  for (const value of array) {
+    if (comparator(target, value)) {
+      return true
+    }
+  }
+  return false
+}
+
+export default arrayIncludesWith

src/.internal/arrayLikeKeys.ts

@@ -0,0 +1,43 @@
+import isArguments from '../isArguments.js'
+import isBuffer from '../isBuffer.js'
+import isIndex from './isIndex.js'
+import isTypedArray from '../isTypedArray.js'
+
+/** Used to check objects for own properties. */
+const hasOwnProperty = Object.prototype.hasOwnProperty
+
+/**
+ * Creates an array of the enumerable property names of the array-like `value`.
+ *
+ * @private
+ * @param {*} value The value to query.
+ * @param {boolean} inherited Specify returning inherited property names.
+ * @returns {Array} Returns the array of property names.
+ */
+function arrayLikeKeys(value, inherited) {
+  const isArr = Array.isArray(value)
+  const isArg = !isArr && isArguments(value)
+  const isBuff = !isArr && !isArg && isBuffer(value)
+  const isType = !isArr && !isArg && !isBuff && isTypedArray(value)
+  const skipIndexes = isArr || isArg || isBuff || isType
+  const length = value.length
+  const result = new Array(skipIndexes ? length : 0)
+  let index = skipIndexes ? -1 : length
+  while (++index < length) {
+    result[index] = `${index}`
+  }
+  for (const key in value) {
+    if ((inherited || hasOwnProperty.call(value, key)) &&
+        !(skipIndexes && (
+        // Safari 9 has enumerable `arguments.length` in strict mode.
+          (key === 'length' ||
+           // Skip index properties.
+           isIndex(key, length))
+        ))) {
+      result.push(key)
+    }
+  }
+  return result
+}
+
+export default arrayLikeKeys

src/.internal/arrayReduce.ts

@@ -0,0 +1,25 @@
+/**
+ * A specialized version of `reduce` for arrays.
+ *
+ * @private
+ * @param {Array} [array] The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {*} [accumulator] The initial value.
+ * @param {boolean} [initAccum] Specify using the first element of `array` as
+ *  the initial value.
+ * @returns {*} Returns the accumulated value.
+ */
+function arrayReduce(array, iteratee, accumulator, initAccum) {
+  let index = -1
+  const length = array == null ? 0 : array.length
+
+  if (initAccum && length) {
+    accumulator = array[++index]
+  }
+  while (++index < length) {
+    accumulator = iteratee(accumulator, array[index], index, array)
+  }
+  return accumulator
+}
+
+export default arrayReduce

src/.internal/arrayReduceRight.ts

@@ -0,0 +1,23 @@
+/**
+ * A specialized version of `reduceRight` for arrays.
+ *
+ * @private
+ * @param {Array} [array] The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {*} [accumulator] The initial value.
+ * @param {boolean} [initAccum] Specify using the last element of `array` as
+ *  the initial value.
+ * @returns {*} Returns the accumulated value.
+ */
+function arrayReduceRight(array, iteratee, accumulator, initAccum) {
+  let length = array == null ? 0 : array.length
+  if (initAccum && length) {
+    accumulator = array[--length]
+  }
+  while (length--) {
+    accumulator = iteratee(accumulator, array[length], length, array)
+  }
+  return accumulator
+}
+
+export default arrayReduceRight

src/.internal/asciiSize.ts

@@ -0,0 +1,12 @@
+/**
+ * Gets the size of an ASCII `string`.
+ *
+ * @private
+ * @param {string} string The string inspect.
+ * @returns {number} Returns the string size.
+ */
+function asciiSize({ length }) {
+  return length
+}
+
+export default asciiSize

src/.internal/asciiToArray.ts

@@ -0,0 +1,12 @@
+/**
+ * Converts an ASCII `string` to an array.
+ *
+ * @private
+ * @param {string} string The string to convert.
+ * @returns {Array} Returns the converted array.
+ */
+function asciiToArray(string) {
+  return string.split('')
+}
+
+export default asciiToArray

src/.internal/assignMergeValue.ts

@@ -0,0 +1,20 @@
+import baseAssignValue from './baseAssignValue.js'
+import eq from '../eq.js'
+
+/**
+ * This function is like `assignValue` except that it doesn't assign
+ * `undefined` values.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {string} key The key of the property to assign.
+ * @param {*} value The value to assign.
+ */
+function assignMergeValue(object, key, value) {
+  if ((value !== undefined && !eq(object[key], value)) ||
+      (value === undefined && !(key in object))) {
+    baseAssignValue(object, key, value)
+  }
+}
+
+export default assignMergeValue

src/.internal/assignValue.ts

@@ -0,0 +1,27 @@
+import baseAssignValue from './baseAssignValue.js'
+import eq from '../eq.js'
+
+/** Used to check objects for own properties. */
+const hasOwnProperty = Object.prototype.hasOwnProperty
+
+/**
+ * Assigns `value` to `key` of `object` if the existing value is not equivalent.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {string} key The key of the property to assign.
+ * @param {*} value The value to assign.
+ */
+function assignValue(object, key, value) {
+  const objValue = object[key]
+
+  if (!(hasOwnProperty.call(object, key) && eq(objValue, value))) {
+    if (value !== 0 || (1 / value) === (1 / objValue)) {
+      baseAssignValue(object, key, value)
+    }
+  } else if (value === undefined && !(key in object)) {
+    baseAssignValue(object, key, value)
+  }
+}
+
+export default assignValue

src/.internal/assocIndexOf.ts

@@ -0,0 +1,21 @@
+import eq from '../eq.js'
+
+/**
+ * Gets the index at which the `key` is found in `array` of key-value pairs.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {*} key The key to search for.
+ * @returns {number} Returns the index of the matched value, else `-1`.
+ */
+function assocIndexOf(array, key) {
+  let { length } = array
+  while (length--) {
+    if (eq(array[length][0], key)) {
+      return length
+    }
+  }
+  return -1
+}
+
+export default assocIndexOf

src/.internal/baseAssignValue.ts

@@ -0,0 +1,23 @@
+/**
+ * The base implementation of `assignValue` and `assignMergeValue` without
+ * value checks.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {string} key The key of the property to assign.
+ * @param {*} value The value to assign.
+ */
+function baseAssignValue(object, key, value) {
+  if (key == '__proto__') {
+    Object.defineProperty(object, key, {
+      'configurable': true,
+      'enumerable': true,
+      'value': value,
+      'writable': true
+    })
+  } else {
+    object[key] = value
+  }
+}
+
+export default baseAssignValue

src/.internal/baseAt.ts

@@ -0,0 +1,23 @@
+import get from '../get.js'
+
+/**
+ * The base implementation of `at` without support for individual paths.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {string[]} paths The property paths to pick.
+ * @returns {Array} Returns the picked elements.
+ */
+function baseAt(object, paths) {
+  let index = -1
+  const length = paths.length
+  const result = new Array(length)
+  const skip = object == null
+
+  while (++index < length) {
+    result[index] = skip ? undefined : get(object, paths[index])
+  }
+  return result
+}
+
+export default baseAt

src/.internal/baseClone.ts

@@ -0,0 +1,241 @@
+import Stack from './Stack.js'
+import arrayEach from './arrayEach.js'
+import assignValue from './assignValue.js'
+import cloneBuffer from './cloneBuffer.js'
+import copyArray from './copyArray.js'
+import copyObject from './copyObject.js'
+import cloneArrayBuffer from './cloneArrayBuffer.js'
+import cloneDataView from './cloneDataView.js'
+import cloneRegExp from './cloneRegExp.js'
+import cloneSymbol from './cloneSymbol.js'
+import cloneTypedArray from './cloneTypedArray.js'
+import copySymbols from './copySymbols.js'
+import copySymbolsIn from './copySymbolsIn.js'
+import getAllKeys from './getAllKeys.js'
+import getAllKeysIn from './getAllKeysIn.js'
+import getTag from './getTag.js'
+import initCloneObject from './initCloneObject.js'
+import isBuffer from '../isBuffer.js'
+import isObject from '../isObject.js'
+import isTypedArray from '../isTypedArray.js'
+import keys from '../keys.js'
+import keysIn from '../keysIn.js'
+
+/** Used to compose bitmasks for cloning. */
+const CLONE_DEEP_FLAG = 1
+const CLONE_FLAT_FLAG = 2
+const CLONE_SYMBOLS_FLAG = 4
+
+/** `Object#toString` result references. */
+const argsTag = '[object Arguments]'
+const arrayTag = '[object Array]'
+const boolTag = '[object Boolean]'
+const dateTag = '[object Date]'
+const errorTag = '[object Error]'
+const mapTag = '[object Map]'
+const numberTag = '[object Number]'
+const objectTag = '[object Object]'
+const regexpTag = '[object RegExp]'
+const setTag = '[object Set]'
+const stringTag = '[object String]'
+const symbolTag = '[object Symbol]'
+const weakMapTag = '[object WeakMap]'
+
+const arrayBufferTag = '[object ArrayBuffer]'
+const dataViewTag = '[object DataView]'
+const float32Tag = '[object Float32Array]'
+const float64Tag = '[object Float64Array]'
+const int8Tag = '[object Int8Array]'
+const int16Tag = '[object Int16Array]'
+const int32Tag = '[object Int32Array]'
+const uint8Tag = '[object Uint8Array]'
+const uint8ClampedTag = '[object Uint8ClampedArray]'
+const uint16Tag = '[object Uint16Array]'
+const uint32Tag = '[object Uint32Array]'
+
+/** Used to identify `toStringTag` values supported by `clone`. */
+const cloneableTags = {}
+cloneableTags[argsTag] = cloneableTags[arrayTag] =
+cloneableTags[arrayBufferTag] = cloneableTags[dataViewTag] =
+cloneableTags[boolTag] = cloneableTags[dateTag] =
+cloneableTags[float32Tag] = cloneableTags[float64Tag] =
+cloneableTags[int8Tag] = cloneableTags[int16Tag] =
+cloneableTags[int32Tag] = cloneableTags[mapTag] =
+cloneableTags[numberTag] = cloneableTags[objectTag] =
+cloneableTags[regexpTag] = cloneableTags[setTag] =
+cloneableTags[stringTag] = cloneableTags[symbolTag] =
+cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] =
+cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true
+cloneableTags[errorTag] = cloneableTags[weakMapTag] = false
+
+/** Used to check objects for own properties. */
+const hasOwnProperty = Object.prototype.hasOwnProperty
+
+/**
+ * Initializes an object clone based on its `toStringTag`.
+ *
+ * **Note:** This function only supports cloning values with tags of
+ * `Boolean`, `Date`, `Error`, `Map`, `Number`, `RegExp`, `Set`, or `String`.
+ *
+ * @private
+ * @param {Object} object The object to clone.
+ * @param {string} tag The `toStringTag` of the object to clone.
+ * @param {boolean} [isDeep] Specify a deep clone.
+ * @returns {Object} Returns the initialized clone.
+ */
+function initCloneByTag(object, tag, isDeep) {
+  const Ctor = object.constructor
+  switch (tag) {
+    case arrayBufferTag:
+      return cloneArrayBuffer(object)
+
+    case boolTag:
+    case dateTag:
+      return new Ctor(+object)
+
+    case dataViewTag:
+      return cloneDataView(object, isDeep)
+
+    case float32Tag: case float64Tag:
+    case int8Tag: case int16Tag: case int32Tag:
+    case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag:
+      return cloneTypedArray(object, isDeep)
+
+    case mapTag:
+      return new Ctor
+
+    case numberTag:
+    case stringTag:
+      return new Ctor(object)
+
+    case regexpTag:
+      return cloneRegExp(object)
+
+    case setTag:
+      return new Ctor
+
+    case symbolTag:
+      return cloneSymbol(object)
+  }
+}
+
+/**
+ * Initializes an array clone.
+ *
+ * @private
+ * @param {Array} array The array to clone.
+ * @returns {Array} Returns the initialized clone.
+ */
+function initCloneArray(array) {
+  const { length } = array
+  const result = new array.constructor(length)
+
+  // Add properties assigned by `RegExp#exec`.
+  if (length && typeof array[0] === 'string' && hasOwnProperty.call(array, 'index')) {
+    result.index = array.index
+    result.input = array.input
+  }
+  return result
+}
+
+/**
+ * The base implementation of `clone` and `cloneDeep` which tracks
+ * traversed objects.
+ *
+ * @private
+ * @param {*} value The value to clone.
+ * @param {number} bitmask The bitmask flags.
+ *  1 - Deep clone
+ *  2 - Flatten inherited properties
+ *  4 - Clone symbols
+ * @param {Function} [customizer] The function to customize cloning.
+ * @param {string} [key] The key of `value`.
+ * @param {Object} [object] The parent object of `value`.
+ * @param {Object} [stack] Tracks traversed objects and their clone counterparts.
+ * @returns {*} Returns the cloned value.
+ */
+function baseClone(value, bitmask, customizer, key, object, stack) {
+  let result
+  const isDeep = bitmask & CLONE_DEEP_FLAG
+  const isFlat = bitmask & CLONE_FLAT_FLAG
+  const isFull = bitmask & CLONE_SYMBOLS_FLAG
+
+  if (customizer) {
+    result = object ? customizer(value, key, object, stack) : customizer(value)
+  }
+  if (result !== undefined) {
+    return result
+  }
+  if (!isObject(value)) {
+    return value
+  }
+  const isArr = Array.isArray(value)
+  const tag = getTag(value)
+  if (isArr) {
+    result = initCloneArray(value)
+    if (!isDeep) {
+      return copyArray(value, result)
+    }
+  } else {
+    const isFunc = typeof value === 'function'
+
+    if (isBuffer(value)) {
+      return cloneBuffer(value, isDeep)
+    }
+    if (tag == objectTag || tag == argsTag || (isFunc && !object)) {
+      result = (isFlat || isFunc) ? {} : initCloneObject(value)
+      if (!isDeep) {
+        return isFlat
+          ? copySymbolsIn(value, copyObject(value, keysIn(value), result))
+          : copySymbols(value, Object.assign(result, value))
+      }
+    } else {
+      if (isFunc || !cloneableTags[tag]) {
+        return object ? value : {}
+      }
+      result = initCloneByTag(value, tag, isDeep)
+    }
+  }
+  // Check for circular references and return its corresponding clone.
+  stack || (stack = new Stack)
+  const stacked = stack.get(value)
+  if (stacked) {
+    return stacked
+  }
+  stack.set(value, result)
+
+  if (tag == mapTag) {
+    value.forEach((subValue, key) => {
+      result.set(key, baseClone(subValue, bitmask, customizer, key, value, stack))
+    })
+    return result
+  }
+
+  if (tag == setTag) {
+    value.forEach((subValue) => {
+      result.add(baseClone(subValue, bitmask, customizer, subValue, value, stack))
+    })
+    return result
+  }
+
+  if (isTypedArray(value)) {
+    return result
+  }
+
+  const keysFunc = isFull
+    ? (isFlat ? getAllKeysIn : getAllKeys)
+    : (isFlat ? keysIn : keys)
+
+  const props = isArr ? undefined : keysFunc(value)
+  arrayEach(props || value, (subValue, key) => {
+    if (props) {
+      key = subValue
+      subValue = value[key]
+    }
+    // Recursively populate clone (susceptible to call stack limits).
+    assignValue(result, key, baseClone(subValue, bitmask, customizer, key, value, stack))
+  })
+  return result
+}
+
+export default baseClone

src/.internal/baseConforms.ts

@@ -0,0 +1,16 @@
+import baseConformsTo from './baseConformsTo.js'
+import keys from '../keys.js'
+
+/**
+ * The base implementation of `conforms` which doesn't clone `source`.
+ *
+ * @private
+ * @param {Object} source The object of property predicates to conform to.
+ * @returns {Function} Returns the new spec function.
+ */
+function baseConforms(source) {
+  const props = keys(source)
+  return (object) => baseConformsTo(object, source, props)
+}
+
+export default baseConforms

src/.internal/baseConformsTo.ts

@@ -0,0 +1,27 @@
+/**
+ * The base implementation of `conformsTo` which accepts `props` to check.
+ *
+ * @private
+ * @param {Object} object The object to inspect.
+ * @param {Object} source The object of property predicates to conform to.
+ * @returns {boolean} Returns `true` if `object` conforms, else `false`.
+ */
+function baseConformsTo(object, source, props) {
+  let length = props.length
+  if (object == null) {
+    return !length
+  }
+  object = Object(object)
+  while (length--) {
+    const key = props[length]
+    const predicate = source[key]
+    const value = object[key]
+
+    if ((value === undefined && !(key in object)) || !predicate(value)) {
+      return false
+    }
+  }
+  return true
+}
+
+export default baseConformsTo

src/.internal/baseDifference.ts

@@ -0,0 +1,63 @@
+import SetCache from './SetCache.js'
+import arrayIncludes from './arrayIncludes.js'
+import arrayIncludesWith from './arrayIncludesWith.js'
+import map from '../map.js'
+import cacheHas from './cacheHas.js'
+
+/** Used as the size to enable large array optimizations. */
+const LARGE_ARRAY_SIZE = 200
+
+/**
+ * The base implementation of methods like `difference` without support
+ * for excluding multiple arrays.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {Array} values The values to exclude.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns the new array of filtered values.
+ */
+function baseDifference(array, values, iteratee, comparator) {
+  let includes = arrayIncludes
+  let isCommon = true
+  const result = []
+  const valuesLength = values.length
+
+  if (!array.length) {
+    return result
+  }
+  if (iteratee) {
+    values = map(values, (value) => iteratee(value))
+  }
+  if (comparator) {
+    includes = arrayIncludesWith
+    isCommon = false
+  }
+  else if (values.length >= LARGE_ARRAY_SIZE) {
+    includes = cacheHas
+    isCommon = false
+    values = new SetCache(values)
+  }
+  outer:
+  for (let value of array) {
+    const computed = iteratee == null ? value : iteratee(value)
+
+    value = (comparator || value !== 0) ? value : 0
+    if (isCommon && computed === computed) {
+      let valuesIndex = valuesLength
+      while (valuesIndex--) {
+        if (values[valuesIndex] === computed) {
+          continue outer
+        }
+      }
+      result.push(value)
+    }
+    else if (!includes(values, computed, comparator)) {
+      result.push(value)
+    }
+  }
+  return result
+}
+
+export default baseDifference

src/.internal/baseEach.ts

@@ -0,0 +1,31 @@
+import baseForOwn from './baseForOwn.js'
+import isArrayLike from '../isArrayLike.js'
+
+/**
+ * The base implementation of `forEach`.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Array|Object} Returns `collection`.
+ */
+function baseEach(collection, iteratee) {
+  if (collection == null) {
+    return collection
+  }
+  if (!isArrayLike(collection)) {
+    return baseForOwn(collection, iteratee)
+  }
+  const length = collection.length
+  const iterable = Object(collection)
+  let index = -1
+
+  while (++index < length) {
+    if (iteratee(iterable[index], index, iterable) === false) {
+      break
+    }
+  }
+  return collection
+}
+
+export default baseEach

src/.internal/baseEachRight.ts

@@ -0,0 +1,30 @@
+import baseForOwnRight from './baseForOwnRight.js'
+import isArrayLike from '../isArrayLike.js'
+
+/**
+ * The base implementation of `forEachRight`.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Array|Object} Returns `collection`.
+ */
+function baseEachRight(collection, iteratee) {
+  if (collection == null) {
+    return collection
+  }
+  if (!isArrayLike(collection)) {
+    return baseForOwnRight(collection, iteratee)
+  }
+  const iterable = Object(collection)
+  let length = collection.length
+
+  while (length--) {
+    if (iteratee(iterable[length], length, iterable) === false) {
+      break
+    }
+  }
+  return collection
+}
+
+export default baseEachRight

src/.internal/baseFindIndex.ts

@@ -0,0 +1,23 @@
+/**
+ * The base implementation of `findIndex` and `findLastIndex`.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {Function} predicate The function invoked per iteration.
+ * @param {number} fromIndex The index to search from.
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {number} Returns the index of the matched value, else `-1`.
+ */
+function baseFindIndex(array, predicate, fromIndex, fromRight) {
+  const { length } = array
+  let index = fromIndex + (fromRight ? 1 : -1)
+
+  while ((fromRight ? index-- : ++index < length)) {
+    if (predicate(array[index], index, array)) {
+      return index
+    }
+  }
+  return -1
+}
+
+export default baseFindIndex

src/.internal/baseFindKey.ts

@@ -0,0 +1,22 @@
+/**
+ * The base implementation of methods like `findKey` and `findLastKey`
+ * which iterates over `collection` using `eachFunc`.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to inspect.
+ * @param {Function} predicate The function invoked per iteration.
+ * @param {Function} eachFunc The function to iterate over `collection`.
+ * @returns {*} Returns the found element or its key, else `undefined`.
+ */
+function baseFindKey(collection, predicate, eachFunc) {
+  let result
+  eachFunc(collection, (value, key, collection) => {
+    if (predicate(value, key, collection)) {
+      result = key
+      return false
+    }
+  })
+  return result
+}
+
+export default baseFindKey

src/.internal/baseFlatten.ts

@@ -0,0 +1,37 @@
+import isFlattenable from './isFlattenable.js'
+
+/**
+ * The base implementation of `flatten` with support for restricting flattening.
+ *
+ * @private
+ * @param {Array} array The array to flatten.
+ * @param {number} depth The maximum recursion depth.
+ * @param {boolean} [predicate=isFlattenable] The function invoked per iteration.
+ * @param {boolean} [isStrict] Restrict to values that pass `predicate` checks.
+ * @param {Array} [result=[]] The initial result value.
+ * @returns {Array} Returns the new flattened array.
+ */
+function baseFlatten(array, depth, predicate, isStrict, result) {
+  predicate || (predicate = isFlattenable)
+  result || (result = [])
+
+  if (array == null) {
+    return result
+  }
+
+  for (const value of array) {
+    if (depth > 0 && predicate(value)) {
+      if (depth > 1) {
+        // Recursively flatten arrays (susceptible to call stack limits).
+        baseFlatten(value, depth - 1, predicate, isStrict, result)
+      } else {
+        result.push(...value)
+      }
+    } else if (!isStrict) {
+      result[result.length] = value
+    }
+  }
+  return result
+}
+
+export default baseFlatten

src/.internal/baseFor.ts

@@ -0,0 +1,27 @@
+/**
+ * The base implementation of `baseForOwn` which iterates over `object`
+ * properties returned by `keysFunc` and invokes `iteratee` for each property.
+ * Iteratee functions may exit iteration early by explicitly returning `false`.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {Function} keysFunc The function to get the keys of `object`.
+ * @returns {Object} Returns `object`.
+ */
+function baseFor(object, iteratee, keysFunc) {
+  const iterable = Object(object)
+  const props = keysFunc(object)
+  let { length } = props
+  let index = -1
+
+  while (length--) {
+    const key = props[++index]
+    if (iteratee(iterable[key], key, iterable) === false) {
+      break
+    }
+  }
+  return object
+}
+
+export default baseFor

src/.internal/baseForOwn.ts

@@ -0,0 +1,16 @@
+import baseFor from './baseFor.js'
+import keys from '../keys.js'
+
+/**
+ * The base implementation of `forOwn`.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Object} Returns `object`.
+ */
+function baseForOwn(object, iteratee) {
+  return object && baseFor(object, iteratee, keys)
+}
+
+export default baseForOwn

src/.internal/baseForOwnRight.ts

@@ -0,0 +1,16 @@
+import baseForRight from './baseForRight.js'
+import keys from '../keys.js'
+
+/**
+ * The base implementation of `forOwnRight`.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {Object} Returns `object`.
+ */
+function baseForOwnRight(object, iteratee) {
+  return object && baseForRight(object, iteratee, keys)
+}
+
+export default baseForOwnRight

src/.internal/baseForRight.ts

@@ -0,0 +1,25 @@
+/**
+ * This function is like `baseFor` except that it iterates over properties
+ * in the opposite order.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {Function} keysFunc The function to get the keys of `object`.
+ * @returns {Object} Returns `object`.
+ */
+function baseForRight(object, iteratee, keysFunc) {
+  const iterable = Object(object)
+  const props = keysFunc(object)
+  let { length } = props
+
+  while (length--) {
+    const key = props[length]
+    if (iteratee(iterable[key], key, iterable) === false) {
+      break
+    }
+  }
+  return object
+}
+
+export default baseForRight

src/.internal/baseGet.ts

@@ -0,0 +1,24 @@
+import castPath from './castPath.js'
+import toKey from './toKey.js'
+
+/**
+ * The base implementation of `get` without support for default values.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @param {Array|string} path The path of the property to get.
+ * @returns {*} Returns the resolved value.
+ */
+function baseGet(object, path) {
+  path = castPath(path, object)
+
+  let index = 0
+  const length = path.length
+
+  while (object != null && index < length) {
+    object = object[toKey(path[index++])]
+  }
+  return (index && index == length) ? object : undefined
+}
+
+export default baseGet

src/.internal/baseInRange.ts

@@ -0,0 +1,14 @@
+/**
+ * The base implementation of `inRange` which doesn't coerce arguments.
+ *
+ * @private
+ * @param {number} number The number to check.
+ * @param {number} start The start of the range.
+ * @param {number} end The end of the range.
+ * @returns {boolean} Returns `true` if `number` is in the range, else `false`.
+ */
+function baseInRange(number, start, end) {
+  return number >= Math.min(start, end) && number < Math.max(start, end)
+}
+
+export default baseInRange

src/.internal/baseIndexOf.ts

@@ -0,0 +1,20 @@
+import baseFindIndex from './baseFindIndex.js'
+import baseIsNaN from './baseIsNaN.js'
+import strictIndexOf from './strictIndexOf.js'
+
+/**
+ * The base implementation of `indexOf` without `fromIndex` bounds checks.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {*} value The value to search for.
+ * @param {number} fromIndex The index to search from.
+ * @returns {number} Returns the index of the matched value, else `-1`.
+ */
+function baseIndexOf(array, value, fromIndex) {
+  return value === value
+    ? strictIndexOf(array, value, fromIndex)
+    : baseFindIndex(array, baseIsNaN, fromIndex)
+}
+
+export default baseIndexOf

src/.internal/baseIndexOfWith.ts

@@ -0,0 +1,23 @@
+/**
+ * This function is like `baseIndexOf` except that it accepts a comparator.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {*} value The value to search for.
+ * @param {number} fromIndex The index to search from.
+ * @param {Function} comparator The comparator invoked per element.
+ * @returns {number} Returns the index of the matched value, else `-1`.
+ */
+function baseIndexOfWith(array, value, fromIndex, comparator) {
+  let index = fromIndex - 1
+  const { length } = array
+
+  while (++index < length) {
+    if (comparator(array[index], value)) {
+      return index
+    }
+  }
+  return -1
+}
+
+export default baseIndexOfWith

src/.internal/baseIntersection.ts

@@ -0,0 +1,72 @@
+import SetCache from './SetCache.js'
+import arrayIncludes from './arrayIncludes.js'
+import arrayIncludesWith from './arrayIncludesWith.js'
+import map from '../map.js'
+import cacheHas from './cacheHas.js'
+
+/**
+ * The base implementation of methods like `intersection` that accepts an
+ * array of arrays to inspect.
+ *
+ * @private
+ * @param {Array} arrays The arrays to inspect.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns the new array of shared values.
+ */
+function baseIntersection(arrays, iteratee, comparator) {
+  const includes = comparator ? arrayIncludesWith : arrayIncludes
+  const length = arrays[0].length
+  const othLength = arrays.length
+  const caches = new Array(othLength)
+  const result = []
+
+  let array
+  let maxLength = Infinity
+  let othIndex = othLength
+
+  while (othIndex--) {
+    array = arrays[othIndex]
+    if (othIndex && iteratee) {
+      array = map(array, (value) => iteratee(value))
+    }
+    maxLength = Math.min(array.length, maxLength)
+    caches[othIndex] = !comparator && (iteratee || (length >= 120 && array.length >= 120))
+      ? new SetCache(othIndex && array)
+      : undefined
+  }
+  array = arrays[0]
+
+  let index = -1
+  const seen = caches[0]
+
+  outer:
+  while (++index < length && result.length < maxLength) {
+    let value = array[index]
+    const computed = iteratee ? iteratee(value) : value
+
+    value = (comparator || value !== 0) ? value : 0
+    if (!(seen
+      ? cacheHas(seen, computed)
+      : includes(result, computed, comparator)
+    )) {
+      othIndex = othLength
+      while (--othIndex) {
+        const cache = caches[othIndex]
+        if (!(cache
+          ? cacheHas(cache, computed)
+          : includes(arrays[othIndex], computed, comparator))
+        ) {
+          continue outer
+        }
+      }
+      if (seen) {
+        seen.push(computed)
+      }
+      result.push(value)
+    }
+  }
+  return result
+}
+
+export default baseIntersection

src/.internal/baseIsEqual.ts

@@ -0,0 +1,28 @@
+import baseIsEqualDeep from './baseIsEqualDeep.js'
+import isObjectLike from '../isObjectLike.js'
+
+/**
+ * The base implementation of `isEqual` which supports partial comparisons
+ * and tracks traversed objects.
+ *
+ * @private
+ * @param {*} value The value to compare.
+ * @param {*} other The other value to compare.
+ * @param {boolean} bitmask The bitmask flags.
+ *  1 - Unordered comparison
+ *  2 - Partial comparison
+ * @param {Function} [customizer] The function to customize comparisons.
+ * @param {Object} [stack] Tracks traversed `value` and `other` objects.
+ * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
+ */
+function baseIsEqual(value, other, bitmask, customizer, stack) {
+  if (value === other) {
+    return true
+  }
+  if (value == null || other == null || (!isObjectLike(value) && !isObjectLike(other))) {
+    return value !== value && other !== other
+  }
+  return baseIsEqualDeep(value, other, bitmask, customizer, baseIsEqual, stack)
+}
+
+export default baseIsEqual

src/.internal/baseIsEqualDeep.ts

@@ -0,0 +1,79 @@
+import Stack from './Stack.js'
+import equalArrays from './equalArrays.js'
+import equalByTag from './equalByTag.js'
+import equalObjects from './equalObjects.js'
+import getTag from './getTag.js'
+import isBuffer from '../isBuffer.js'
+import isTypedArray from '../isTypedArray.js'
+
+/** Used to compose bitmasks for value comparisons. */
+const COMPARE_PARTIAL_FLAG = 1
+
+/** `Object#toString` result references. */
+const argsTag = '[object Arguments]'
+const arrayTag = '[object Array]'
+const objectTag = '[object Object]'
+
+/** Used to check objects for own properties. */
+const hasOwnProperty = Object.prototype.hasOwnProperty
+
+/**
+ * A specialized version of `baseIsEqual` for arrays and objects which performs
+ * deep comparisons and tracks traversed objects enabling objects with circular
+ * references to be compared.
+ *
+ * @private
+ * @param {Object} object The object to compare.
+ * @param {Object} other The other object to compare.
+ * @param {number} bitmask The bitmask flags. See `baseIsEqual` for more details.
+ * @param {Function} customizer The function to customize comparisons.
+ * @param {Function} equalFunc The function to determine equivalents of values.
+ * @param {Object} [stack] Tracks traversed `object` and `other` objects.
+ * @returns {boolean} Returns `true` if the objects are equivalent, else `false`.
+ */
+function baseIsEqualDeep(object, other, bitmask, customizer, equalFunc, stack) {
+  let objIsArr = Array.isArray(object)
+  const othIsArr = Array.isArray(other)
+  let objTag = objIsArr ? arrayTag : getTag(object)
+  let othTag = othIsArr ? arrayTag : getTag(other)
+
+  objTag = objTag == argsTag ? objectTag : objTag
+  othTag = othTag == argsTag ? objectTag : othTag
+
+  let objIsObj = objTag == objectTag
+  const othIsObj = othTag == objectTag
+  const isSameTag = objTag == othTag
+
+  if (isSameTag && isBuffer(object)) {
+    if (!isBuffer(other)) {
+      return false
+    }
+    objIsArr = true
+    objIsObj = false
+  }
+  if (isSameTag && !objIsObj) {
+    stack || (stack = new Stack)
+    return (objIsArr || isTypedArray(object))
+      ? equalArrays(object, other, bitmask, customizer, equalFunc, stack)
+      : equalByTag(object, other, objTag, bitmask, customizer, equalFunc, stack)
+  }
+  if (!(bitmask & COMPARE_PARTIAL_FLAG)) {
+    const objIsWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__')
+    const othIsWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__')
+
+    if (objIsWrapped || othIsWrapped) {
+      const objUnwrapped = objIsWrapped ? object.value() : object
+      const othUnwrapped = othIsWrapped ? other.value() : other
+
+      stack || (stack = new Stack)
+      return equalFunc(objUnwrapped, othUnwrapped, bitmask, customizer, stack)
+    }
+  }
+  if (!isSameTag) {
+    return false
+  }
+  stack || (stack = new Stack)
+  return equalObjects(object, other, bitmask, customizer, equalFunc, stack)
+}
+
+export default baseIsEqualDeep

src/.internal/baseIsMatch.ts

@@ -0,0 +1,64 @@
+import Stack from './Stack.js'
+import baseIsEqual from './baseIsEqual.js'
+
+/** Used to compose bitmasks for value comparisons. */
+const COMPARE_PARTIAL_FLAG = 1
+const COMPARE_UNORDERED_FLAG = 2
+
+/**
+ * The base implementation of `isMatch`.
+ *
+ * @private
+ * @param {Object} object The object to inspect.
+ * @param {Object} source The object of property values to match.
+ * @param {Array} matchData The property names, values, and compare flags to match.
+ * @param {Function} [customizer] The function to customize comparisons.
+ * @returns {boolean} Returns `true` if `object` is a match, else `false`.
+ */
+function baseIsMatch(object, source, matchData, customizer) {
+  let index = matchData.length
+  const length = index
+  const noCustomizer = !customizer
+
+  if (object == null) {
+    return !length
+  }
+  let data
+  let result
+  object = Object(object)
+  while (index--) {
+    data = matchData[index]
+    if ((noCustomizer && data[2])
+      ? data[1] !== object[data[0]]
+      : !(data[0] in object)
+    ) {
+      return false
+    }
+  }
+  while (++index < length) {
+    data = matchData[index]
+    const key = data[0]
+    const objValue = object[key]
+    const srcValue = data[1]
+
+    if (noCustomizer && data[2]) {
+      if (objValue === undefined && !(key in object)) {
+        return false
+      }
+    } else {
+      const stack = new Stack
+      if (customizer) {
+        result = customizer(objValue, srcValue, key, object, source, stack)
+      }
+      if (!(result === undefined
+        ? baseIsEqual(srcValue, objValue, COMPARE_PARTIAL_FLAG | COMPARE_UNORDERED_FLAG, customizer, stack)
+        : result
+      )) {
+        return false
+      }
+    }
+  }
+  return true
+}
+
+export default baseIsMatch

src/.internal/baseIsNaN.ts

@@ -0,0 +1,12 @@
+/**
+ * The base implementation of `isNaN` without support for number objects.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`.
+ */
+function baseIsNaN(value) {
+  return value !== value
+}
+
+export default baseIsNaN

src/.internal/baseMatches.ts

@@ -0,0 +1,20 @@
+import baseIsMatch from './baseIsMatch.js'
+import getMatchData from './getMatchData.js'
+import matchesStrictComparable from './matchesStrictComparable.js'
+
+/**
+ * The base implementation of `matches` which doesn't clone `source`.
+ *
+ * @private
+ * @param {Object} source The object of property values to match.
+ * @returns {Function} Returns the new spec function.
+ */
+function baseMatches(source) {
+  const matchData = getMatchData(source)
+  if (matchData.length === 1 && matchData[0][2]) {
+    return matchesStrictComparable(matchData[0][0], matchData[0][1])
+  }
+  return (object) => object === source || baseIsMatch(object, source, matchData)
+}
+
+export default baseMatches

src/.internal/baseMatchesProperty.ts

@@ -0,0 +1,33 @@
+import baseIsEqual from './baseIsEqual.js'
+import get from '../get.js'
+import hasIn from '../hasIn.js'
+import isKey from './isKey.js'
+import isStrictComparable from './isStrictComparable.js'
+import matchesStrictComparable from './matchesStrictComparable.js'
+import toKey from './toKey.js'
+
+/** Used to compose bitmasks for value comparisons. */
+const COMPARE_PARTIAL_FLAG = 1
+const COMPARE_UNORDERED_FLAG = 2
+
+/**
+ * The base implementation of `matchesProperty` which doesn't clone `srcValue`.
+ *
+ * @private
+ * @param {string} path The path of the property to get.
+ * @param {*} srcValue The value to match.
+ * @returns {Function} Returns the new spec function.
+ */
+function baseMatchesProperty(path, srcValue) {
+  if (isKey(path) && isStrictComparable(srcValue)) {
+    return matchesStrictComparable(toKey(path), srcValue)
+  }
+  return (object) => {
+    const objValue = get(object, path)
+    return (objValue === undefined && objValue === srcValue)
+      ? hasIn(object, path)
+      : baseIsEqual(srcValue, objValue, COMPARE_PARTIAL_FLAG | COMPARE_UNORDERED_FLAG)
+  }
+}
+
+export default baseMatchesProperty

src/.internal/baseMerge.ts

@@ -0,0 +1,41 @@
+import Stack from './Stack.js'
+import assignMergeValue from './assignMergeValue.js'
+import baseFor from './baseFor.js'
+import baseMergeDeep from './baseMergeDeep.js'
+import isObject from '../isObject.js'
+import keysIn from '../keysIn.js'
+
+/**
+ * The base implementation of `merge` without support for multiple sources.
+ *
+ * @private
+ * @param {Object} object The destination object.
+ * @param {Object} source The source object.
+ * @param {number} srcIndex The index of `source`.
+ * @param {Function} [customizer] The function to customize merged values.
+ * @param {Object} [stack] Tracks traversed source values and their merged
+ *  counterparts.
+ */
+function baseMerge(object, source, srcIndex, customizer, stack) {
+  if (object === source) {
+    return
+  }
+  baseFor(source, (srcValue, key) => {
+    if (isObject(srcValue)) {
+      stack || (stack = new Stack)
+      baseMergeDeep(object, source, key, srcIndex, baseMerge, customizer, stack)
+    }
+    else {
+      let newValue = customizer
+        ? customizer(object[key], srcValue, `${key}`, object, source, stack)
+        : undefined
+
+      if (newValue === undefined) {
+        newValue = srcValue
+      }
+      assignMergeValue(object, key, newValue)
+    }
+  }, keysIn)
+}
+
+export default baseMerge

src/.internal/baseMergeDeep.ts

@@ -0,0 +1,91 @@
+import assignMergeValue from './assignMergeValue.js'
+import cloneBuffer from './cloneBuffer.js'
+import cloneTypedArray from './cloneTypedArray.js'
+import copyArray from './copyArray.js'
+import initCloneObject from './initCloneObject.js'
+import isArguments from '../isArguments.js'
+import isArrayLikeObject from '../isArrayLikeObject.js'
+import isBuffer from '../isBuffer.js'
+import isObject from '../isObject.js'
+import isPlainObject from '../isPlainObject.js'
+import isTypedArray from '../isTypedArray.js'
+import toPlainObject from '../toPlainObject.js'
+
+/**
+ * A specialized version of `baseMerge` for arrays and objects which performs
+ * deep merges and tracks traversed objects enabling objects with circular
+ * references to be merged.
+ *
+ * @private
+ * @param {Object} object The destination object.
+ * @param {Object} source The source object.
+ * @param {string} key The key of the value to merge.
+ * @param {number} srcIndex The index of `source`.
+ * @param {Function} mergeFunc The function to merge values.
+ * @param {Function} [customizer] The function to customize assigned values.
+ * @param {Object} [stack] Tracks traversed source values and their merged
+ *  counterparts.
+ */
+function baseMergeDeep(object, source, key, srcIndex, mergeFunc, customizer, stack) {
+  const objValue = object[key]
+  const srcValue = source[key]
+  const stacked = stack.get(srcValue)
+
+  if (stacked) {
+    assignMergeValue(object, key, stacked)
+    return
+  }
+  let newValue = customizer
+    ? customizer(objValue, srcValue, `${key}`, object, source, stack)
+    : undefined
+
+  let isCommon = newValue === undefined
+
+  if (isCommon) {
+    const isArr = Array.isArray(srcValue)
+    const isBuff = !isArr && isBuffer(srcValue)
+    const isTyped = !isArr && !isBuff && isTypedArray(srcValue)
+
+    newValue = srcValue
+    if (isArr || isBuff || isTyped) {
+      if (Array.isArray(objValue)) {
+        newValue = objValue
+      }
+      else if (isArrayLikeObject(objValue)) {
+        newValue = copyArray(objValue)
+      }
+      else if (isBuff) {
+        isCommon = false
+        newValue = cloneBuffer(srcValue, true)
+      }
+      else if (isTyped) {
+        isCommon = false
+        newValue = cloneTypedArray(srcValue, true)
+      }
+      else {
+        newValue = []
+      }
+    }
+    else if (isPlainObject(srcValue) || isArguments(srcValue)) {
+      newValue = objValue
+      if (isArguments(objValue)) {
+        newValue = toPlainObject(objValue)
+      }
+      else if (typeof objValue === 'function' || !isObject(objValue)) {
+        newValue = initCloneObject(srcValue)
+      }
+    }
+    else {
+      isCommon = false
+    }
+  }
+  if (isCommon) {
+    // Recursively merge objects and arrays (susceptible to call stack limits).
+    stack.set(srcValue, newValue)
+    mergeFunc(newValue, srcValue, srcIndex, customizer, stack)
+    stack['delete'](srcValue)
+  }
+  assignMergeValue(object, key, newValue)
+}
+
+export default baseMergeDeep

src/.internal/baseOrderBy.ts

@@ -0,0 +1,49 @@
+import baseEach from './baseEach.js'
+import baseSortBy from './baseSortBy.js'
+import baseGet from './baseGet.js'
+import compareMultiple from './compareMultiple.js'
+import isArrayLike from '../isArrayLike.js'
+
+const identity = (value) => value
+
+/**
+ * The base implementation of `orderBy` without param guards.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by.
+ * @param {string[]} orders The sort orders of `iteratees`.
+ * @returns {Array} Returns the new sorted array.
+ */
+function baseOrderBy(collection, iteratees, orders) {
+  if (iteratees.length) {
+    iteratees = iteratees.map((iteratee) => {
+      if (Array.isArray(iteratee)) {
+        return (value) => baseGet(value, iteratee.length === 1 ? iteratee[0] : iteratee)
+      }
+
+      return iteratee
+    })
+  } else {
+    iteratees = [identity]
+  }
+
+  let criteriaIndex = -1
+  let eachIndex = -1
+
+  const result = isArrayLike(collection) ? new Array(collection.length) : []
+
+  baseEach(collection, (value) => {
+    const criteria = iteratees.map((iteratee) => iteratee(value))
+
+    result[++eachIndex] = {
+      criteria,
+      index: ++criteriaIndex,
+      value
+    }
+  })
+
+  return baseSortBy(result, (object, other) => compareMultiple(object, other, orders))
+}
+
+export default baseOrderBy

src/.internal/basePick.ts

@@ -0,0 +1,17 @@
+import basePickBy from './basePickBy.js'
+import hasIn from '../hasIn.js'
+
+/**
+ * The base implementation of `pick` without support for individual
+ * property identifiers.
+ *
+ * @private
+ * @param {Object} object The source object.
+ * @param {string[]} paths The property paths to pick.
+ * @returns {Object} Returns the new object.
+ */
+function basePick(object, paths) {
+  return basePickBy(object, paths, (value, path) => hasIn(object, path))
+}
+
+export default basePick

src/.internal/basePickBy.ts

@@ -0,0 +1,29 @@
+import baseGet from './baseGet.js'
+import baseSet from './baseSet.js'
+import castPath from './castPath.js'
+
+/**
+ * The base implementation of `pickBy`.
+ *
+ * @private
+ * @param {Object} object The source object.
+ * @param {string[]} paths The property paths to pick.
+ * @param {Function} predicate The function invoked per property.
+ * @returns {Object} Returns the new object.
+ */
+function basePickBy(object, paths, predicate) {
+  let index = -1
+  const length = paths.length
+  const result = {}
+
+  while (++index < length) {
+    const path = paths[index]
+    const value = baseGet(object, path)
+    if (predicate(value, path)) {
+      baseSet(result, castPath(path, object), value)
+    }
+  }
+  return result
+}
+
+export default basePickBy

src/.internal/baseProperty.ts

@@ -0,0 +1,12 @@
+/**
+ * The base implementation of `property` without support for deep paths.
+ *
+ * @private
+ * @param {string} key The key of the property to get.
+ * @returns {Function} Returns the new accessor function.
+ */
+function baseProperty(key) {
+  return (object) => object == null ? undefined : object[key]
+}
+
+export default baseProperty

src/.internal/basePropertyDeep.ts

@@ -0,0 +1,14 @@
+import baseGet from './baseGet.js'
+
+/**
+ * A specialized version of `baseProperty` which supports deep paths.
+ *
+ * @private
+ * @param {Array|string} path The path of the property to get.
+ * @returns {Function} Returns the new accessor function.
+ */
+function basePropertyDeep(path) {
+  return (object) => baseGet(object, path)
+}
+
+export default basePropertyDeep

src/.internal/basePropertyOf.ts

@@ -0,0 +1,12 @@
+/**
+ * The base implementation of `propertyOf` without support for deep paths.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @returns {Function} Returns the new accessor function.
+ */
+function basePropertyOf(object) {
+  return (key) => object == null ? undefined : object[key]
+}
+
+export default basePropertyOf

src/.internal/basePullAll.ts

@@ -0,0 +1,44 @@
+import map from '../map.js'
+import baseIndexOf from './baseIndexOf.js'
+import baseIndexOfWith from './baseIndexOfWith.js'
+import copyArray from './copyArray.js'
+
+/**
+ * The base implementation of `pullAllBy`.
+ *
+ * @private
+ * @param {Array} array The array to modify.
+ * @param {Array} values The values to remove.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns `array`.
+ */
+function basePullAll(array, values, iteratee, comparator) {
+  const indexOf = comparator ? baseIndexOfWith : baseIndexOf
+  const length = values.length
+
+  let index = -1
+  let seen = array
+
+  if (array === values) {
+    values = copyArray(values)
+  }
+  if (iteratee) {
+    seen = map(array, (value) => iteratee(value))
+  }
+  while (++index < length) {
+    let fromIndex = 0
+    const value = values[index]
+    const computed = iteratee ? iteratee(value) : value
+
+    while ((fromIndex = indexOf(seen, computed, fromIndex, comparator)) > -1) {
+      if (seen !== array) {
+        seen.splice(fromIndex, 1)
+      }
+      array.splice(fromIndex, 1)
+    }
+  }
+  return array
+}
+
+export default basePullAll

src/.internal/basePullAt.ts

@@ -0,0 +1,32 @@
+import baseUnset from './baseUnset.js'
+import isIndex from './isIndex.js'
+
+/**
+ * The base implementation of `pullAt` without support for individual
+ * indexes or capturing the removed elements.
+ *
+ * @private
+ * @param {Array} array The array to modify.
+ * @param {number[]} indexes The indexes of elements to remove.
+ * @returns {Array} Returns `array`.
+ */
+function basePullAt(array, indexes) {
+  let length = array ? indexes.length : 0
+  const lastIndex = length - 1
+
+  while (length--) {
+    let previous
+    const index = indexes[length]
+    if (length === lastIndex || index !== previous) {
+      previous = index
+      if (isIndex(index)) {
+        array.splice(index, 1)
+      } else {
+        baseUnset(array, index)
+      }
+    }
+  }
+  return array
+}
+
+export default basePullAt

src/.internal/baseRange.ts

@@ -0,0 +1,24 @@
+/**
+ * The base implementation of `range` and `rangeRight` which doesn't
+ * coerce arguments.
+ *
+ * @private
+ * @param {number} start The start of the range.
+ * @param {number} end The end of the range.
+ * @param {number} step The value to increment or decrement by.
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {Array} Returns the range of numbers.
+ */
+function baseRange(start, end, step, fromRight) {
+  let index = -1
+  let length = Math.max(Math.ceil((end - start) / (step || 1)), 0)
+  const result = new Array(length)
+
+  while (length--) {
+    result[fromRight ? length : ++index] = start
+    start += step
+  }
+  return result
+}
+
+export default baseRange

src/.internal/baseReduce.ts

@@ -0,0 +1,23 @@
+/**
+ * The base implementation of `reduce` and `reduceRight` which iterates
+ * over `collection` using `eachFunc`.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {*} accumulator The initial value.
+ * @param {boolean} initAccum Specify using the first or last element of
+ *  `collection` as the initial value.
+ * @param {Function} eachFunc The function to iterate over `collection`.
+ * @returns {*} Returns the accumulated value.
+ */
+function baseReduce(collection, iteratee, accumulator, initAccum, eachFunc) {
+  eachFunc(collection, (value, index, collection) => {
+    accumulator = initAccum
+      ? (initAccum = false, value)
+      : iteratee(accumulator, value, index, collection)
+  })
+  return accumulator
+}
+
+export default baseReduce

src/.internal/baseSet.ts

@@ -0,0 +1,48 @@
+import assignValue from './assignValue.js'
+import castPath from './castPath.js'
+import isIndex from './isIndex.js'
+import isObject from '../isObject.js'
+import toKey from './toKey.js'
+
+/**
+ * The base implementation of `set`.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {Array|string} path The path of the property to set.
+ * @param {*} value The value to set.
+ * @param {Function} [customizer] The function to customize path creation.
+ * @returns {Object} Returns `object`.
+ */
+function baseSet(object, path, value, customizer) {
+  if (!isObject(object)) {
+    return object
+  }
+  path = castPath(path, object)
+
+  const length = path.length
+  const lastIndex = length - 1
+
+  let index = -1
+  let nested = object
+
+  while (nested != null && ++index < length) {
+    const key = toKey(path[index])
+    let newValue = value
+
+    if (index != lastIndex) {
+      const objValue = nested[key]
+      newValue = customizer ? customizer(objValue, key, nested) : undefined
+      if (newValue === undefined) {
+        newValue = isObject(objValue)
+          ? objValue
+          : (isIndex(path[index + 1]) ? [] : {})
+      }
+    }
+    assignValue(nested, key, newValue)
+    nested = nested[key]
+  }
+  return object
+}
+
+export default baseSet

src/.internal/baseSortBy.ts

@@ -0,0 +1,21 @@
+/**
+ * The base implementation of `sortBy` which uses `comparer` to define the
+ * sort order of `array` and replaces criteria objects with their corresponding
+ * values.
+ *
+ * @private
+ * @param {Array} array The array to sort.
+ * @param {Function} comparer The function to define sort order.
+ * @returns {Array} Returns `array`.
+ */
+function baseSortBy(array, comparer) {
+  let { length } = array
+
+  array.sort(comparer)
+  while (length--) {
+    array[length] = array[length].value
+  }
+  return array
+}
+
+export default baseSortBy

src/.internal/baseSortedIndex.ts

@@ -0,0 +1,40 @@
+import baseSortedIndexBy from './baseSortedIndexBy.js'
+import isSymbol from '../isSymbol.js'
+
+/** Used as references for the maximum length and index of an array. */
+const MAX_ARRAY_LENGTH = 4294967295
+const HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1
+
+/**
+ * The base implementation of `sortedIndex` and `sortedLastIndex` which
+ * performs a binary search of `array` to determine the index at which `value`
+ * should be inserted into `array` in order to maintain its sort order.
+ *
+ * @private
+ * @param {Array} array The sorted array to inspect.
+ * @param {*} value The value to evaluate.
+ * @param {boolean} [retHighest] Specify returning the highest qualified index.
+ * @returns {number} Returns the index at which `value` should be inserted
+ *  into `array`.
+ */
+function baseSortedIndex(array, value, retHighest) {
+  let low = 0
+  let high = array == null ? low : array.length
+
+  if (typeof value === 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) {
+    while (low < high) {
+      const mid = (low + high) >>> 1
+      const computed = array[mid]
+      if (computed !== null && !isSymbol(computed) &&
+          (retHighest ? (computed <= value) : (computed < value))) {
+        low = mid + 1
+      } else {
+        high = mid
+      }
+    }
+    return high
+  }
+  return baseSortedIndexBy(array, value, (value) => value, retHighest)
+}
+
+export default baseSortedIndex

src/.internal/baseSortedIndexBy.ts

@@ -0,0 +1,65 @@
+import isSymbol from '../isSymbol.js'
+
+/** Used as references for the maximum length and index of an array. */
+const MAX_ARRAY_LENGTH = 4294967295
+const MAX_ARRAY_INDEX = MAX_ARRAY_LENGTH - 1
+
+/**
+ * The base implementation of `sortedIndexBy` and `sortedLastIndexBy`
+ * which invokes `iteratee` for `value` and each element of `array` to compute
+ * their sort ranking. The iteratee is invoked with one argument (value).
+ *
+ * @private
+ * @param {Array} array The sorted array to inspect.
+ * @param {*} value The value to evaluate.
+ * @param {Function} iteratee The iteratee invoked per element.
+ * @param {boolean} [retHighest] Specify returning the highest qualified index.
+ * @returns {number} Returns the index at which `value` should be inserted
+ *  into `array`.
+ */
+function baseSortedIndexBy(array, value, iteratee, retHighest) {
+  let low = 0
+  let high = array == null ? 0 : array.length
+  if (high == 0) {
+    return 0
+  }
+
+  value = iteratee(value)
+
+  const valIsNaN = value !== value
+  const valIsNull = value === null
+  const valIsSymbol = isSymbol(value)
+  const valIsUndefined = value === undefined
+
+  while (low < high) {
+    let setLow
+    const mid = Math.floor((low + high) / 2)
+    const computed = iteratee(array[mid])
+    const othIsDefined = computed !== undefined
+    const othIsNull = computed === null
+    const othIsReflexive = computed === computed
+    const othIsSymbol = isSymbol(computed)
+
+    if (valIsNaN) {
+      setLow = retHighest || othIsReflexive
+    } else if (valIsUndefined) {
+      setLow = othIsReflexive && (retHighest || othIsDefined)
+    } else if (valIsNull) {
+      setLow = othIsReflexive && othIsDefined && (retHighest || !othIsNull)
+    } else if (valIsSymbol) {
+      setLow = othIsReflexive && othIsDefined && !othIsNull && (retHighest || !othIsSymbol)
+    } else if (othIsNull || othIsSymbol) {
+      setLow = false
+    } else {
+      setLow = retHighest ? (computed <= value) : (computed < value)
+    }
+    if (setLow) {
+      low = mid + 1
+    } else {
+      high = mid
+    }
+  }
+  return Math.min(high, MAX_ARRAY_INDEX)
+}
+
+export default baseSortedIndexBy

src/.internal/baseSortedUniq.ts

@@ -0,0 +1,29 @@
+import eq from '../eq.js'
+
+/**
+ * The base implementation of `sortedUniq` and `sortedUniqBy`.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @returns {Array} Returns the new duplicate free array.
+ */
+function baseSortedUniq(array, iteratee) {
+  let seen
+  let index = -1
+  let resIndex = 0
+
+  const { length } = array
+  const result = []
+
+  while (++index < length) {
+    const value = array[index], computed = iteratee ? iteratee(value) : value
+    if (!index || !eq(computed, seen)) {
+      seen = computed
+      result[resIndex++] = value === 0 ? 0 : value
+    }
+  }
+  return result
+}
+
+export default baseSortedUniq

src/.internal/baseSum.ts

@@ -0,0 +1,21 @@
+/**
+ * The base implementation of `sum` and `sumBy`.
+ *
+ * @private
+ * @param {Array} array The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @returns {number} Returns the sum.
+ */
+function baseSum(array, iteratee) {
+  let result
+
+  for (const value of array) {
+    const current = iteratee(value)
+    if (current !== undefined) {
+      result = result === undefined ? current : (result + current)
+    }
+  }
+  return result
+}
+
+export default baseSum

src/.internal/baseToNumber.ts

@@ -0,0 +1,24 @@
+import isSymbol from '../isSymbol.js'
+
+/** Used as references for various `Number` constants. */
+const NAN = 0 / 0
+
+/**
+ * The base implementation of `toNumber` which doesn't ensure correct
+ * conversions of binary, hexadecimal, or octal string values.
+ *
+ * @private
+ * @param {*} value The value to process.
+ * @returns {number} Returns the number.
+ */
+function baseToNumber(value) {
+  if (typeof value === 'number') {
+    return value
+  }
+  if (isSymbol(value)) {
+    return NAN
+  }
+  return +value
+}
+
+export default baseToNumber

src/.internal/baseToString.ts

@@ -0,0 +1,33 @@
+import isSymbol from '../isSymbol.js'
+
+/** Used as references for various `Number` constants. */
+const INFINITY = 1 / 0
+
+/** Used to convert symbols to primitives and strings. */
+const symbolToString = Symbol.prototype.toString
+
+/**
+ * The base implementation of `toString` which doesn't convert nullish
+ * values to empty strings.
+ *
+ * @private
+ * @param {*} value The value to process.
+ * @returns {string} Returns the string.
+ */
+function baseToString(value) {
+  // Exit early for strings to avoid a performance hit in some environments.
+  if (typeof value === 'string') {
+    return value
+  }
+  if (Array.isArray(value)) {
+    // Recursively convert values (susceptible to call stack limits).
+    return `${value.map(baseToString)}`
+  }
+  if (isSymbol(value)) {
+    return symbolToString ? symbolToString.call(value) : ''
+  }
+  const result = `${value}`
+  return (result === '0' && (1 / value) === -INFINITY) ? '-0' : result
+}
+
+export default baseToString

src/.internal/baseUniq.ts

@@ -0,0 +1,73 @@
+import SetCache from './SetCache.js'
+import arrayIncludes from './arrayIncludes.js'
+import arrayIncludesWith from './arrayIncludesWith.js'
+import cacheHas from './cacheHas.js'
+import createSet from './createSet.js'
+import setToArray from './setToArray.js'
+
+/** Used as the size to enable large array optimizations. */
+const LARGE_ARRAY_SIZE = 200
+
+/**
+ * The base implementation of `uniqBy`.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns the new duplicate free array.
+ */
+function baseUniq(array, iteratee, comparator) {
+  let index = -1
+  let includes = arrayIncludes
+  let isCommon = true
+
+  const { length } = array
+  const result = []
+  let seen = result
+
+  if (comparator) {
+    isCommon = false
+    includes = arrayIncludesWith
+  }
+  else if (length >= LARGE_ARRAY_SIZE) {
+    const set = iteratee ? null : createSet(array)
+    if (set) {
+      return setToArray(set)
+    }
+    isCommon = false
+    includes = cacheHas
+    seen = new SetCache
+  }
+  else {
+    seen = iteratee ? [] : result
+  }
+  outer:
+  while (++index < length) {
+    let value = array[index]
+    const computed = iteratee ? iteratee(value) : value
+
+    value = (comparator || value !== 0) ? value : 0
+    if (isCommon && computed === computed) {
+      let seenIndex = seen.length
+      while (seenIndex--) {
+        if (seen[seenIndex] === computed) {
+          continue outer
+        }
+      }
+      if (iteratee) {
+        seen.push(computed)
+      }
+      result.push(value)
+    }
+    else if (!includes(seen, computed, comparator)) {
+      if (seen !== result) {
+        seen.push(computed)
+      }
+      result.push(value)
+    }
+  }
+  return result
+}
+
+export default baseUniq

src/.internal/baseUnset.ts

@@ -0,0 +1,20 @@
+import castPath from './castPath.js'
+import last from '../last.js'
+import parent from './parent.js'
+import toKey from './toKey.js'
+
+/**
+ * The base implementation of `unset`.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {Array|string} path The property path to unset.
+ * @returns {boolean} Returns `true` if the property is deleted, else `false`.
+ */
+function baseUnset(object, path) {
+  path = castPath(path, object)
+  object = parent(object, path)
+  return object == null || delete object[toKey(last(path))]
+}
+
+export default baseUnset

src/.internal/baseUpdate.ts

@@ -0,0 +1,18 @@
+import baseGet from './baseGet.js'
+import baseSet from './baseSet.js'
+
+/**
+ * The base implementation of `update`.
+ *
+ * @private
+ * @param {Object} object The object to modify.
+ * @param {Array|string} path The path of the property to update.
+ * @param {Function} updater The function to produce the updated value.
+ * @param {Function} [customizer] The function to customize path creation.
+ * @returns {Object} Returns `object`.
+ */
+function baseUpdate(object, path, updater, customizer) {
+  return baseSet(object, path, updater(baseGet(object, path)), customizer)
+}
+
+export default baseUpdate

src/.internal/baseValues.ts

@@ -0,0 +1,15 @@
+/**
+ * The base implementation of `values` and `valuesIn` which creates an
+ * array of `object` property values corresponding to the property names
+ * of `props`.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @param {Array} props The property names to get values for.
+ * @returns {Object} Returns the array of property values.
+ */
+function baseValues(object, props) {
+  return props == null ? [] : props.map((key) => object[key])
+}
+
+export default baseValues

src/.internal/baseWhile.ts

@@ -0,0 +1,25 @@
+import slice from '../slice.js'
+
+/**
+ * The base implementation of methods like `dropWhile` and `takeWhile`.
+ *
+ * @private
+ * @param {Array} array The array to query.
+ * @param {Function} predicate The function invoked per iteration.
+ * @param {boolean} [isDrop] Specify dropping elements instead of taking them.
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {Array} Returns the slice of `array`.
+ */
+function baseWhile(array, predicate, isDrop, fromRight) {
+  const { length } = array
+  let index = fromRight ? length : -1
+
+  while ((fromRight ? index-- : ++index < length) &&
+    predicate(array[index], index, array)) {}
+
+  return isDrop
+    ? slice(array, (fromRight ? 0 : index), (fromRight ? index + 1 : length))
+    : slice(array, (fromRight ? index + 1 : 0), (fromRight ? length : index))
+}
+
+export default baseWhile

src/.internal/baseXor.ts

@@ -0,0 +1,36 @@
+import baseDifference from './baseDifference.js'
+import baseFlatten from './baseFlatten.js'
+import baseUniq from './baseUniq.js'
+
+/**
+ * The base implementation of methods like `xor` which accepts an array of
+ * arrays to inspect.
+ *
+ * @private
+ * @param {Array} arrays The arrays to inspect.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns the new array of values.
+ */
+function baseXor(arrays, iteratee, comparator) {
+  const length = arrays.length
+  if (length < 2) {
+    return length ? baseUniq(arrays[0]) : []
+  }
+  let index = -1
+  const result = new Array(length)
+
+  while (++index < length) {
+    const array = arrays[index]
+    let othIndex = -1
+
+    while (++othIndex < length) {
+      if (othIndex != index) {
+        result[index] = baseDifference(result[index] || array, arrays[othIndex], iteratee, comparator)
+      }
+    }
+  }
+  return baseUniq(baseFlatten(result, 1), iteratee, comparator)
+}
+
+export default baseXor

src/.internal/baseZipObject.ts

@@ -0,0 +1,23 @@
+/**
+ * This base implementation of `zipObject` which assigns values using `assignFunc`.
+ *
+ * @private
+ * @param {Array} props The property identifiers.
+ * @param {Array} values The property values.
+ * @param {Function} assignFunc The function to assign values.
+ * @returns {Object} Returns the new object.
+ */
+function baseZipObject(props, values, assignFunc) {
+  let index = -1
+  const length = props.length
+  const valsLength = values.length
+  const result = {}
+
+  while (++index < length) {
+    const value = index < valsLength ? values[index] : undefined
+    assignFunc(result, props[index], value)
+  }
+  return result
+}
+
+export default baseZipObject

src/.internal/cacheHas.ts

@@ -0,0 +1,13 @@
+/**
+ * Checks if a `cache` value for `key` exists.
+ *
+ * @private
+ * @param {Object} cache The cache to query.
+ * @param {string} key The key of the entry to check.
+ * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+ */
+function cacheHas(cache, key) {
+  return cache.has(key)
+}
+
+export default cacheHas

src/.internal/castArrayLikeObject.ts

@@ -0,0 +1,14 @@
+import isArrayLikeObject from '../isArrayLikeObject.js'
+
+/**
+ * Casts `value` to an empty array if it's not an array like object.
+ *
+ * @private
+ * @param {*} value The value to inspect.
+ * @returns {Array|Object} Returns the cast array-like object.
+ */
+function castArrayLikeObject(value) {
+  return isArrayLikeObject(value) ? value : []
+}
+
+export default castArrayLikeObject

src/.internal/castPath.ts

@@ -0,0 +1,19 @@
+import isKey from './isKey.js'
+import stringToPath from './stringToPath.js'
+
+/**
+ * Casts `value` to a path array if it's not one.
+ *
+ * @private
+ * @param {*} value The value to inspect.
+ * @param {Object} [object] The object to query keys on.
+ * @returns {Array} Returns the cast property path array.
+ */
+function castPath(value, object) {
+  if (Array.isArray(value)) {
+    return value
+  }
+  return isKey(value, object) ? [value] : stringToPath(value)
+}
+
+export default castPath

src/.internal/castSlice.ts

@@ -0,0 +1,18 @@
+import slice from '../slice.js'
+
+/**
+ * Casts `array` to a slice if it's needed.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {number} start The start position.
+ * @param {number} [end=array.length] The end position.
+ * @returns {Array} Returns the cast slice.
+ */
+function castSlice(array, start, end) {
+  const { length } = array
+  end = end === undefined ? length : end
+  return (!start && end >= length) ? array : slice(array, start, end)
+}
+
+export default castSlice

src/.internal/charsEndIndex.ts

@@ -0,0 +1,19 @@
+import baseIndexOf from './baseIndexOf.js'
+
+/**
+ * Used by `trim` and `trimEnd` to get the index of the last string symbol
+ * that is not found in the character symbols.
+ *
+ * @private
+ * @param {Array} strSymbols The string symbols to inspect.
+ * @param {Array} chrSymbols The character symbols to find.
+ * @returns {number} Returns the index of the last unmatched string symbol.
+ */
+function charsEndIndex(strSymbols, chrSymbols) {
+  let index = strSymbols.length
+
+  while (index-- && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
+  return index
+}
+
+export default charsEndIndex

src/.internal/charsStartIndex.ts

@@ -0,0 +1,20 @@
+import baseIndexOf from './baseIndexOf.js'
+
+/**
+ * Used by `trim` and `trimStart` to get the index of the first string symbol
+ * that is not found in the character symbols.
+ *
+ * @private
+ * @param {Array} strSymbols The string symbols to inspect.
+ * @param {Array} chrSymbols The character symbols to find.
+ * @returns {number} Returns the index of the first unmatched string symbol.
+ */
+function charsStartIndex(strSymbols, chrSymbols) {
+  let index = -1
+  const length = strSymbols.length
+
+  while (++index < length && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
+  return index
+}
+
+export default charsStartIndex

src/.internal/cloneArrayBuffer.ts

@@ -0,0 +1,14 @@
+/**
+ * Creates a clone of `arrayBuffer`.
+ *
+ * @private
+ * @param {ArrayBuffer} arrayBuffer The array buffer to clone.
+ * @returns {ArrayBuffer} Returns the cloned array buffer.
+ */
+function cloneArrayBuffer(arrayBuffer) {
+  const result = new arrayBuffer.constructor(arrayBuffer.byteLength)
+  new Uint8Array(result).set(new Uint8Array(arrayBuffer))
+  return result
+}
+
+export default cloneArrayBuffer

src/.internal/cloneBuffer.ts

@@ -0,0 +1,34 @@
+import root from './root.js'
+
+/** Detect free variable `exports`. */
+const freeExports = typeof exports === 'object' && exports !== null && !exports.nodeType && exports
+
+/** Detect free variable `module`. */
+const freeModule = freeExports && typeof module === 'object' && module !== null && !module.nodeType && module
+
+/** Detect the popular CommonJS extension `module.exports`. */
+const moduleExports = freeModule && freeModule.exports === freeExports
+
+/** Built-in value references. */
+const Buffer = moduleExports ? root.Buffer : undefined, allocUnsafe = Buffer ? Buffer.allocUnsafe : undefined
+
+/**
+ * Creates a clone of `buffer`.
+ *
+ * @private
+ * @param {Buffer} buffer The buffer to clone.
+ * @param {boolean} [isDeep] Specify a deep clone.
+ * @returns {Buffer} Returns the cloned buffer.
+ */
+function cloneBuffer(buffer, isDeep) {
+  if (isDeep) {
+    return buffer.slice()
+  }
+  const length = buffer.length
+  const result = allocUnsafe ? allocUnsafe(length) : new buffer.constructor(length)
+
+  buffer.copy(result)
+  return result
+}
+
+export default cloneBuffer

src/.internal/cloneDataView.ts

@@ -0,0 +1,16 @@
+import cloneArrayBuffer from './cloneArrayBuffer.js'
+
+/**
+ * Creates a clone of `dataView`.
+ *
+ * @private
+ * @param {Object} dataView The data view to clone.
+ * @param {boolean} [isDeep] Specify a deep clone.
+ * @returns {Object} Returns the cloned data view.
+ */
+function cloneDataView(dataView, isDeep) {
+  const buffer = isDeep ? cloneArrayBuffer(dataView.buffer) : dataView.buffer
+  return new dataView.constructor(buffer, dataView.byteOffset, dataView.byteLength)
+}
+
+export default cloneDataView

src/.internal/cloneRegExp.ts

@@ -0,0 +1,17 @@
+/** Used to match `RegExp` flags from their coerced string values. */
+const reFlags = /\w*$/
+
+/**
+ * Creates a clone of `regexp`.
+ *
+ * @private
+ * @param {Object} regexp The regexp to clone.
+ * @returns {Object} Returns the cloned regexp.
+ */
+function cloneRegExp(regexp) {
+  const result = new regexp.constructor(regexp.source, reFlags.exec(regexp))
+  result.lastIndex = regexp.lastIndex
+  return result
+}
+
+export default cloneRegExp

src/.internal/cloneSymbol.ts

@@ -0,0 +1,15 @@
+/** Used to convert symbols to primitives and strings. */
+const symbolValueOf = Symbol.prototype.valueOf
+
+/**
+ * Creates a clone of the `symbol` object.
+ *
+ * @private
+ * @param {Object} symbol The symbol object to clone.
+ * @returns {Object} Returns the cloned symbol object.
+ */
+function cloneSymbol(symbol) {
+  return Object(symbolValueOf.call(symbol))
+}
+
+export default cloneSymbol

src/.internal/cloneTypedArray.ts

@@ -0,0 +1,16 @@
+import cloneArrayBuffer from './cloneArrayBuffer.js'
+
+/**
+ * Creates a clone of `typedArray`.
+ *
+ * @private
+ * @param {Object} typedArray The typed array to clone.
+ * @param {boolean} [isDeep] Specify a deep clone.
+ * @returns {Object} Returns the cloned typed array.
+ */
+function cloneTypedArray(typedArray, isDeep) {
+  const buffer = isDeep ? cloneArrayBuffer(typedArray.buffer) : typedArray.buffer
+  return new typedArray.constructor(buffer, typedArray.byteOffset, typedArray.length)
+}
+
+export default cloneTypedArray

src/.internal/compareAscending.ts

@@ -0,0 +1,45 @@
+import isSymbol from '../isSymbol.js'
+
+/**
+ * Compares values to sort them in ascending order.
+ *
+ * @private
+ * @param {*} value The value to compare.
+ * @param {*} other The other value to compare.
+ * @returns {number} Returns the sort order indicator for `value`.
+ */
+function compareAscending(value, other) {
+  if (value !== other) {
+    const valIsDefined = value !== undefined
+    const valIsNull = value === null
+    const valIsReflexive = value === value
+    const valIsSymbol = isSymbol(value)
+
+    const othIsDefined = other !== undefined
+    const othIsNull = other === null
+    const othIsReflexive = other === other
+    const othIsSymbol = isSymbol(other)
+
+    const val = typeof value === 'string'
+      ? value.localeCompare(other)
+      : -other
+
+    if ((!othIsNull && !othIsSymbol && !valIsSymbol && val > 0) ||
+        (valIsSymbol && othIsDefined && othIsReflexive && !othIsNull && !othIsSymbol) ||
+        (valIsNull && othIsDefined && othIsReflexive) ||
+        (!valIsDefined && othIsReflexive) ||
+        !valIsReflexive) {
+      return 1
+    }
+    if ((!valIsNull && !valIsSymbol && !othIsSymbol && val < 0) ||
+        (othIsSymbol && valIsDefined && valIsReflexive && !valIsNull && !valIsSymbol) ||
+        (othIsNull && valIsDefined && valIsReflexive) ||
+        (!othIsDefined && valIsReflexive) ||
+        !othIsReflexive) {
+      return -1
+    }
+  }
+  return 0
+}
+
+export default compareAscending

src/.internal/compareMultiple.ts

@@ -0,0 +1,45 @@
+import compareAscending from './compareAscending.js'
+
+/**
+ * Used by `orderBy` to compare multiple properties of a value to another
+ * and stable sort them.
+ *
+ * If `orders` is unspecified, all values are sorted in ascending order. Otherwise,
+ * specify an order of "desc" for descending or "asc" for ascending sort order
+ * of corresponding values.
+ *
+ * @private
+ * @param {Object} object The object to compare.
+ * @param {Object} other The other object to compare.
+ * @param {(string|function)[]} orders The order to sort by for each property.
+ * @returns {number} Returns the sort order indicator for `object`.
+ */
+function compareMultiple(object, other, orders) {
+  let index = -1
+  const objCriteria = object.criteria
+  const othCriteria = other.criteria
+  const length = objCriteria.length
+  const ordersLength = orders.length
+
+  while (++index < length) {
+    const order = index < ordersLength ? orders[index] : null
+    const cmpFn = (order && typeof order === 'function') ? order: compareAscending
+    const result = cmpFn(objCriteria[index], othCriteria[index])
+    if (result) {
+      if (order && typeof order !== 'function') {
+        return result * (order == 'desc' ? -1 : 1)
+      }
+      return result
+    }
+  }
+  // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications
+  // that causes it, under certain circumstances, to provide the same value for
+  // `object` and `other`. See https://github.com/jashkenas/underscore/pull/1247
+  // for more details.
+  //
+  // This also ensures a stable sort in V8 and other engines.
+  // See https://bugs.chromium.org/p/v8/issues/detail?id=90 for more details.
+  return object.index - other.index
+}
+
+export default compareMultiple

src/.internal/composeArgs.ts

@@ -0,0 +1,38 @@
+/**
+ * Creates an array that is the composition of partially applied arguments,
+ * placeholders, and provided arguments into a single array of arguments.
+ *
+ * @private
+ * @param {Array} args The provided arguments.
+ * @param {Array} partials The arguments to prepend to those provided.
+ * @param {Array} holders The `partials` placeholder indexes.
+ * @params {boolean} [isCurried] Specify composing for a curried function.
+ * @returns {Array} Returns the new array of composed arguments.
+ */
+function composeArgs(args, partials, holders, isCurried) {
+  const argsLength = args.length
+  const holdersLength = holders.length
+  const leftLength = partials.length
+
+  let argsIndex = -1
+  let leftIndex = -1
+  let rangeLength = Math.max(argsLength - holdersLength, 0)
+
+  const result = new Array(leftLength + rangeLength)
+  const isUncurried = !isCurried
+
+  while (++leftIndex < leftLength) {
+    result[leftIndex] = partials[leftIndex]
+  }
+  while (++argsIndex < holdersLength) {
+    if (isUncurried || argsIndex < argsLength) {
+      result[holders[argsIndex]] = args[argsIndex]
+    }
+  }
+  while (rangeLength--) {
+    result[leftIndex++] = args[argsIndex++]
+  }
+  return result
+}
+
+export default composeArgs

src/.internal/composeArgsRight.ts

@@ -0,0 +1,39 @@
+/**
+ * This function is like `composeArgs` except that the arguments composition
+ * is tailored for `partialRight`.
+ *
+ * @private
+ * @param {Array} args The provided arguments.
+ * @param {Array} partials The arguments to append to those provided.
+ * @param {Array} holders The `partials` placeholder indexes.
+ * @params {boolean} [isCurried] Specify composing for a curried function.
+ * @returns {Array} Returns the new array of composed arguments.
+ */
+function composeArgsRight(args, partials, holders, isCurried) {
+  let argsIndex = -1
+  let holdersIndex = -1
+  let rightIndex = -1
+
+  const argsLength = args.length
+  const holdersLength = holders.length
+  const rightLength = partials.length
+  const rangeLength = Math.max(argsLength - holdersLength, 0)
+  const result = new Array(rangeLength + rightLength)
+  const isUncurried = !isCurried
+
+  while (++argsIndex < rangeLength) {
+    result[argsIndex] = args[argsIndex]
+  }
+  const offset = argsIndex
+  while (++rightIndex < rightLength) {
+    result[offset + rightIndex] = partials[rightIndex]
+  }
+  while (++holdersIndex < holdersLength) {
+    if (isUncurried || argsIndex < argsLength) {
+      result[offset + holders[holdersIndex]] = args[argsIndex++]
+    }
+  }
+  return result
+}
+
+export default composeArgsRight

src/.internal/copyArray.ts

@@ -0,0 +1,20 @@
+/**
+ * Copies the values of `source` to `array`.
+ *
+ * @private
+ * @param {Array} source The array to copy values from.
+ * @param {Array} [array=[]] The array to copy values to.
+ * @returns {Array} Returns `array`.
+ */
+function copyArray(source, array) {
+  let index = -1
+  const length = source.length
+
+  array || (array = new Array(length))
+  while (++index < length) {
+    array[index] = source[index]
+  }
+  return array
+}
+
+export default copyArray

src/.internal/copyObject.ts

@@ -0,0 +1,35 @@
+import assignValue from './assignValue.js'
+import baseAssignValue from './baseAssignValue.js'
+
+/**
+ * Copies properties of `source` to `object`.
+ *
+ * @private
+ * @param {Object} source The object to copy properties from.
+ * @param {Array} props The property identifiers to copy.
+ * @param {Object} [object={}] The object to copy properties to.
+ * @param {Function} [customizer] The function to customize copied values.
+ * @returns {Object} Returns `object`.
+ */
+function copyObject(source, props, object, customizer) {
+  const isNew = !object
+  object || (object = {})
+
+  for (const key of props) {
+    let newValue = customizer
+      ? customizer(object[key], source[key], key, object, source)
+      : undefined
+
+    if (newValue === undefined) {
+      newValue = source[key]
+    }
+    if (isNew) {
+      baseAssignValue(object, key, newValue)
+    } else {
+      assignValue(object, key, newValue)
+    }
+  }
+  return object
+}
+
+export default copyObject

src/.internal/copySymbols.ts

@@ -0,0 +1,16 @@
+import copyObject from './copyObject.js'
+import getSymbols from './getSymbols.js'
+
+/**
+ * Copies own symbols of `source` to `object`.
+ *
+ * @private
+ * @param {Object} source The object to copy symbols from.
+ * @param {Object} [object={}] The object to copy symbols to.
+ * @returns {Object} Returns `object`.
+ */
+function copySymbols(source, object) {
+  return copyObject(source, getSymbols(source), object)
+}
+
+export default copySymbols

src/.internal/copySymbolsIn.ts

@@ -0,0 +1,16 @@
+import copyObject from './copyObject.js'
+import getSymbolsIn from './getSymbolsIn.js'
+
+/**
+ * Copies own and inherited symbols of `source` to `object`.
+ *
+ * @private
+ * @param {Object} source The object to copy symbols from.
+ * @param {Object} [object={}] The object to copy symbols to.
+ * @returns {Object} Returns `object`.
+ */
+function copySymbolsIn(source, object) {
+  return copyObject(source, getSymbolsIn(source), object)
+}
+
+export default copySymbolsIn

src/.internal/createAssigner.ts

@@ -0,0 +1,36 @@
+import isIterateeCall from './isIterateeCall.js'
+
+/**
+ * Creates a function like `assign`.
+ *
+ * @private
+ * @param {Function} assigner The function to assign values.
+ * @returns {Function} Returns the new assigner function.
+ */
+function createAssigner(assigner) {
+  return (object, ...sources) => {
+    let index = -1
+    let length = sources.length
+    let customizer = length > 1 ? sources[length - 1] : undefined
+    const guard = length > 2 ? sources[2] : undefined
+
+    customizer = (assigner.length > 3 && typeof customizer === 'function')
+      ? (length--, customizer)
+      : undefined
+
+    if (guard && isIterateeCall(sources[0], sources[1], guard)) {
+      customizer = length < 3 ? undefined : customizer
+      length = 1
+    }
+    object = Object(object)
+    while (++index < length) {
+      const source = sources[index]
+      if (source) {
+        assigner(object, source, index, customizer)
+      }
+    }
+    return object
+  }
+}
+
+export default createAssigner

src/.internal/createCaseFirst.ts

@@ -0,0 +1,34 @@
+import castSlice from './castSlice.js'
+import hasUnicode from './hasUnicode.js'
+import stringToArray from './stringToArray.js'
+
+/**
+ * Creates a function like `lowerFirst`.
+ *
+ * @private
+ * @param {string} methodName The name of the `String` case method to use.
+ * @returns {Function} Returns the new case function.
+ */
+function createCaseFirst(methodName) {
+  return (string) => {
+    if (!string) {
+      return ''
+    }
+
+    const strSymbols = hasUnicode(string)
+      ? stringToArray(string)
+      : undefined
+
+    const chr = strSymbols
+      ? strSymbols[0]
+      : string[0]
+
+    const trailing = strSymbols
+      ? castSlice(strSymbols, 1).join('')
+      : string.slice(1)
+
+    return chr[methodName]() + trailing
+  }
+}
+
+export default createCaseFirst

src/.internal/createMathOperation.ts

@@ -0,0 +1,35 @@
+import baseToNumber from './baseToNumber.js'
+import baseToString from './baseToString.js'
+
+/**
+ * Creates a function that performs a mathematical operation on two values.
+ *
+ * @private
+ * @param {Function} operator The function to perform the operation.
+ * @param {number} [defaultValue] The value used for `undefined` arguments.
+ * @returns {Function} Returns the new mathematical operation function.
+ */
+function createMathOperation(operator, defaultValue) {
+  return (value, other) => {
+    if (value === undefined && other === undefined) {
+      return defaultValue
+    }
+    if (value !== undefined && other === undefined) {
+      return value
+    }
+    if (other !== undefined && value === undefined) {
+      return other
+    }
+    if (typeof value === 'string' || typeof other === 'string') {
+      value = baseToString(value)
+      other = baseToString(other)
+    }
+    else {
+      value = baseToNumber(value)
+      other = baseToNumber(other)
+    }
+    return operator(value, other)
+  }
+}
+
+export default createMathOperation

src/.internal/createPadding.ts

@@ -0,0 +1,30 @@
+import repeat from '../repeat.js'
+import baseToString from './baseToString.js'
+import castSlice from './castSlice.js'
+import hasUnicode from './hasUnicode.js'
+import stringSize from './stringSize.js'
+import stringToArray from './stringToArray.js'
+
+/**
+ * Creates the padding for `string` based on `length`. The `chars` string
+ * is truncated if the number of characters exceeds `length`.
+ *
+ * @private
+ * @param {number} length The padding length.
+ * @param {string} [chars=' '] The string used as padding.
+ * @returns {string} Returns the padding for `string`.
+ */
+function createPadding(length, chars) {
+  chars = chars === undefined ? ' ' : baseToString(chars)
+
+  const charsLength = chars.length
+  if (charsLength < 2) {
+    return charsLength ? repeat(chars, length) : chars
+  }
+  const result = repeat(chars, Math.ceil(length / stringSize(chars)))
+  return hasUnicode(chars)
+    ? castSlice(stringToArray(result), 0, length).join('')
+    : result.slice(0, length)
+}
+
+export default createPadding

src/.internal/createRange.ts

@@ -0,0 +1,26 @@
+import baseRange from './baseRange.js'
+import toFinite from '../toFinite.js'
+
+/**
+ * Creates a `range` or `rangeRight` function.
+ *
+ * @private
+ * @param {boolean} [fromRight] Specify iterating from right to left.
+ * @returns {Function} Returns the new range function.
+ */
+function createRange(fromRight) {
+  return (start, end, step) => {
+    // Ensure the sign of `-0` is preserved.
+    start = toFinite(start)
+    if (end === undefined) {
+      end = start
+      start = 0
+    } else {
+      end = toFinite(end)
+    }
+    step = step === undefined ? (start < end ? 1 : -1) : toFinite(step)
+    return baseRange(start, end, step, fromRight)
+  }
+}
+
+export default createRange

src/.internal/createRound.ts

@@ -0,0 +1,25 @@
+/**
+ * Creates a function like `round`.
+ *
+ * @private
+ * @param {string} methodName The name of the `Math` method to use when rounding.
+ * @returns {Function} Returns the new round function.
+ */
+function createRound(methodName) {
+  const func = Math[methodName]
+  return (number, precision) => {
+    precision = precision == null ? 0 : (precision >= 0 ? Math.min(precision, 292) : Math.max(precision, -292))
+    if (precision) {
+      // Shift with exponential notation to avoid floating-point issues.
+      // See [MDN](https://mdn.io/round#Examples) for more details.
+      let pair = `${number}e`.split('e')
+      const value = func(`${pair[0]}e${+pair[1] + precision}`)
+
+      pair = `${value}e`.split('e')
+      return +`${pair[0]}e${+pair[1] - precision}`
+    }
+    return func(number)
+  }
+}
+
+export default createRound

src/.internal/createSet.ts

@@ -0,0 +1,17 @@
+import setToArray from './setToArray.js'
+
+/** Used as references for various `Number` constants. */
+const INFINITY = 1 / 0
+
+/**
+ * Creates a set object of `values`.
+ *
+ * @private
+ * @param {Array} values The values to add to the set.
+ * @returns {Object} Returns the new set.
+ */
+const createSet = (Set && (1 / setToArray(new Set([,-0]))[1]) == INFINITY)
+  ? (values) => new Set(values)
+  : () => {}
+
+export default createSet