数组相关操作, 或直接操作数组, 或操作结果为数组, 偏工具操作, 大多服务于 runInContext 中挂载在 lodash 上的操作
/**
* A faster alternative to `Function#apply`, this function invokes `func`
* with the `this` binding of `thisArg` and the arguments of `args`.
*
* @private
* @param {Function} func The function to invoke.
* @param {*} thisArg The `this` binding of `func`.
* @param {Array} args The arguments to invoke `func` with.
* @returns {*} Returns the result of `func`.
*/
function apply(func, thisArg, args) {
switch (args.length) {
case 0: return func.call(thisArg);
case 1: return func.call(thisArg, args[0]);
case 2: return func.call(thisArg, args[0], args[1]);
case 3: return func.call(thisArg, args[0], args[1], args[2]);
}
return func.apply(thisArg, args);
}
/**
* A specialized version of `baseAggregator` for arrays.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} setter The function to set `accumulator` values.
* @param {Function} iteratee The iteratee to transform keys.
* @param {Object} accumulator The initial aggregated object.
* @returns {Function} Returns `accumulator`.
*/
function arrayAggregator(array, setter, iteratee, accumulator) {
var index = -1,
length = array == null ? 0 : array.length;
while (++index < length) {
var value = array[index];
setter(accumulator, value, iteratee(value), array);
}
return accumulator;
}
/**
* A specialized version of `_.forEach` for arrays without support for
* iteratee shorthands.
*
* @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) {
var index = -1,
length = array == null ? 0 : array.length;
while (++index < length) {
if (iteratee(array[index], index, array) === false) {
break;
}
}
return array;
}
/**
* A specialized version of `_.forEachRight` for arrays without support for
* iteratee shorthands.
*
* @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) {
var length = array == null ? 0 : array.length;
while (length--) {
if (iteratee(array[length], length, array) === false) {
break;
}
}
return array;
}
/**
* A specialized version of `_.every` for arrays without support for
* iteratee shorthands.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} predicate The function invoked per iteration.
* @returns {boolean} Returns `true` if all elements pass the predicate check,
* else `false`.
*/
function arrayEvery(array, predicate) {
var index = -1,
length = array == null ? 0 : array.length;
while (++index < length) {
if (!predicate(array[index], index, array)) {
return false;
}
}
return true;
}
/**
* A specialized version of `_.filter` for arrays without support for
* iteratee shorthands.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} predicate The function invoked per iteration.
* @returns {Array} Returns the new filtered array.
*/
function arrayFilter(array, predicate) {
var index = -1,
length = array == null ? 0 : array.length,
resIndex = 0,
result = [];
while (++index < length) {
var value = array[index];
if (predicate(value, index, array)) {
result[resIndex++] = value;
}
}
return result;
}
/**
* 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) {
var length = array == null ? 0 : array.length;
return !!length && baseIndexOf(array, value, 0) > -1;
}
/**
* 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, value, comparator) {
var index = -1,
length = array == null ? 0 : array.length;
while (++index < length) {
if (comparator(value, array[index])) {
return true;
}
}
return false;
}
/**
* A specialized version of `_.map` for arrays without support for iteratee
* shorthands.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the new mapped array.
*/
function arrayMap(array, iteratee) {
var index = -1,
length = array == null ? 0 : array.length,
result = Array(length);
while (++index < length) {
result[index] = iteratee(array[index], index, array);
}
return result;
}
/**
* Appends the elements of `values` to `array`.
*
* @private
* @param {Array} array The array to modify.
* @param {Array} values The values to append.
* @returns {Array} Returns `array`.
*/
function arrayPush(array, values) {
var index = -1,
length = values.length,
offset = array.length;
while (++index < length) {
array[offset + index] = values[index];
}
return array;
}
/**
* A specialized version of `_.reduce` for arrays without support for
* iteratee shorthands.
*
* @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) {
var index = -1,
length = array == null ? 0 : array.length;
if (initAccum && length) {
accumulator = array[++index];
}
while (++index < length) {
accumulator = iteratee(accumulator, array[index], index, array);
}
return accumulator;
}
/**
* A specialized version of `_.reduceRight` for arrays without support for
* iteratee shorthands.
*
* @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) {
var length = array == null ? 0 : array.length;
if (initAccum && length) {
accumulator = array[--length];
}
while (length--) {
accumulator = iteratee(accumulator, array[length], length, array);
}
return accumulator;
}
/**
* A specialized version of `_.some` for arrays without support for iteratee
* shorthands.
*
* @private
* @param {Array} [array] The array to iterate over.
* @param {Function} predicate The function invoked per iteration.
* @returns {boolean} Returns `true` if any element passes the predicate check,
* else `false`.
*/
function arraySome(array, predicate) {
var index = -1,
length = array == null ? 0 : array.length;
while (++index < length) {
if (predicate(array[index], index, array)) {
return true;
}
}
return false;
}
/**
* Gets the size of an ASCII `string`.
*
* @private
* @param {string} string The string inspect.
* @returns {number} Returns the string size.
*/
var asciiSize = baseProperty('length');
/**
* 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('');
}
/**
* Splits an ASCII `string` into an array of its words.
*
* @private
* @param {string} The string to inspect.
* @returns {Array} Returns the words of `string`.
*/
function asciiWords(string) {
return string.match(reAsciiWord) || [];
}
/**
* The base implementation of methods like `_.findKey` and `_.findLastKey`,
* without support for iteratee shorthands, 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) {
var result;
eachFunc(collection, function(value, key, collection) {
if (predicate(value, key, collection)) {
result = key;
return false;
}
});
return result;
}
/**
* The base implementation of `_.findIndex` and `_.findLastIndex` without
* support for iteratee shorthands.
*
* @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) {
var length = array.length,
index = fromIndex + (fromRight ? 1 : -1);
while ((fromRight ? index-- : ++index < length)) {
if (predicate(array[index], index, array)) {
return index;
}
}
return -1;
}
/**
* 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);
}
/**
* 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) {
var index = fromIndex - 1,
length = array.length;
while (++index < length) {
if (comparator(array[index], value)) {
return index;
}
}
return -1;
}
/**
* 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;
}
/**
* The base implementation of `_.mean` and `_.meanBy` without support for
* iteratee shorthands.
*
* @private
* @param {Array} array The array to iterate over.
* @param {Function} iteratee The function invoked per iteration.
* @returns {number} Returns the mean.
*/
function baseMean(array, iteratee) {
var length = array == null ? 0 : array.length;
return length ? (baseSum(array, iteratee) / length) : NAN;
}
/**
* 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 function(object) {
return object == null ? undefined : object[key];
};
}
/**
* 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 function(key) {
return object == null ? undefined : object[key];
};
}
/**
* The base implementation of `_.reduce` and `_.reduceRight`, without support
* for iteratee shorthands, 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, function(value, index, collection) {
accumulator = initAccum
? (initAccum = false, value)
: iteratee(accumulator, value, index, collection);
});
return accumulator;
}
/**
* 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) {
var length = array.length;
array.sort(comparer);
while (length--) {
array[length] = array[length].value;
}
return array;
}
/**
* The base implementation of `_.sum` and `_.sumBy` without support for
* iteratee shorthands.
*
* @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) {
var result,
index = -1,
length = array.length;
while (++index < length) {
var current = iteratee(array[index]);
if (current !== undefined) {
result = result === undefined ? current : (result + current);
}
}
return result;
}
/**
* The base implementation of `_.times` without support for iteratee shorthands
* or max array length checks.
*
* @private
* @param {number} n The number of times to invoke `iteratee`.
* @param {Function} iteratee The function invoked per iteration.
* @returns {Array} Returns the array of results.
*/
function baseTimes(n, iteratee) {
var index = -1,
result = Array(n);
while (++index < n) {
result[index] = iteratee(index);
}
return result;
}
/**
* The base implementation of `_.toPairs` and `_.toPairsIn` which creates an array
* of key-value pairs for `object` 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 key-value pairs.
*/
function baseToPairs(object, props) {
return arrayMap(props, function(key) {
return [key, object[key]];
});
}
/**
* The base implementation of `_.unary` without support for storing metadata.
*
* @private
* @param {Function} func The function to cap arguments for.
* @returns {Function} Returns the new capped function.
*/
function baseUnary(func) {
return function(value) {
return func(value);
};
}
/**
* 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 arrayMap(props, function(key) {
return object[key];
});
}
/**
* 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);
}
/**
* 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) {
var index = -1,
length = strSymbols.length;
while (++index < length && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
return index;
}
/**
* 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) {
var index = strSymbols.length;
while (index-- && baseIndexOf(chrSymbols, strSymbols[index], 0) > -1) {}
return index;
}
/**
* Gets the number of `placeholder` occurrences in `array`.
*
* @private
* @param {Array} array The array to inspect.
* @param {*} placeholder The placeholder to search for.
* @returns {number} Returns the placeholder count.
*/
function countHolders(array, placeholder) {
var length = array.length,
result = 0;
while (length--) {
if (array[length] === placeholder) {
++result;
}
}
return result;
}
/**
* Used by `_.deburr` to convert Latin-1 Supplement and Latin Extended-A
* letters to basic Latin letters.
*
* @private
* @param {string} letter The matched letter to deburr.
* @returns {string} Returns the deburred letter.
*/
var deburrLetter = basePropertyOf(deburredLetters);
/**
* Used by `_.escape` to convert characters to HTML entities.
*
* @private
* @param {string} chr The matched character to escape.
* @returns {string} Returns the escaped character.
*/
var escapeHtmlChar = basePropertyOf(htmlEscapes);
/**
* Used by `_.template` to escape characters for inclusion in compiled string literals.
*
* @private
* @param {string} chr The matched character to escape.
* @returns {string} Returns the escaped character.
*/
function escapeStringChar(chr) {
return '\\' + stringEscapes[chr];
}
/**
* Gets the value at `key` of `object`.
*
* @private
* @param {Object} [object] The object to query.
* @param {string} key The key of the property to get.
* @returns {*} Returns the property value.
*/
function getValue(object, key) {
return object == null ? undefined : object[key];
}
/**
* Checks if `string` contains Unicode symbols.
*
* @private
* @param {string} string The string to inspect.
* @returns {boolean} Returns `true` if a symbol is found, else `false`.
*/
function hasUnicode(string) {
return reHasUnicode.test(string);
}
/**
* Checks if `string` contains a word composed of Unicode symbols.
*
* @private
* @param {string} string The string to inspect.
* @returns {boolean} Returns `true` if a word is found, else `false`.
*/
function hasUnicodeWord(string) {
return reHasUnicodeWord.test(string);
}
/**
* Converts `iterator` to an array.
*
* @private
* @param {Object} iterator The iterator to convert.
* @returns {Array} Returns the converted array.
*/
function iteratorToArray(iterator) {
var data,
result = [];
while (!(data = iterator.next()).done) {
result.push(data.value);
}
return result;
}
/**
* Converts `map` to its key-value pairs.
*
* @private
* @param {Object} map The map to convert.
* @returns {Array} Returns the key-value pairs.
*/
function mapToArray(map) {
var index = -1,
result = Array(map.size);
map.forEach(function(value, key) {
result[++index] = [key, value];
});
return result;
}
/**
* Creates a unary function that invokes `func` with its argument transformed.
*
* @private
* @param {Function} func The function to wrap.
* @param {Function} transform The argument transform.
* @returns {Function} Returns the new function.
*/
function overArg(func, transform) {
return function(arg) {
return func(transform(arg));
};
}
/**
* Replaces all `placeholder` elements in `array` with an internal placeholder
* and returns an array of their indexes.
*
* @private
* @param {Array} array The array to modify.
* @param {*} placeholder The placeholder to replace.
* @returns {Array} Returns the new array of placeholder indexes.
*/
function replaceHolders(array, placeholder) {
var index = -1,
length = array.length,
resIndex = 0,
result = [];
while (++index < length) {
var value = array[index];
if (value === placeholder || value === PLACEHOLDER) {
array[index] = PLACEHOLDER;
result[resIndex++] = index;
}
}
return result;
}
/**
* Gets the value at `key`, unless `key` is "__proto__".
*
* @private
* @param {Object} object The object to query.
* @param {string} key The key of the property to get.
* @returns {*} Returns the property value.
*/
function safeGet(object, key) {
return key == '__proto__'
? undefined
: object[key];
}
/**
* Converts `set` to an array of its values.
*
* @private
* @param {Object} set The set to convert.
* @returns {Array} Returns the values.
*/
function setToArray(set) {
var index = -1,
result = Array(set.size);
set.forEach(function(value) {
result[++index] = value;
});
return result;
}
/**
* Converts `set` to its value-value pairs.
*
* @private
* @param {Object} set The set to convert.
* @returns {Array} Returns the value-value pairs.
*/
function setToPairs(set) {
var index = -1,
result = Array(set.size);
set.forEach(function(value) {
result[++index] = [value, value];
});
return result;
}
/**
* A specialized version of `_.indexOf` which performs strict equality
* comparisons of values, i.e. `===`.
*
* @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 strictIndexOf(array, value, fromIndex) {
var index = fromIndex - 1,
length = array.length;
while (++index < length) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* A specialized version of `_.lastIndexOf` which performs strict equality
* comparisons of values, i.e. `===`.
*
* @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 strictLastIndexOf(array, value, fromIndex) {
var index = fromIndex + 1;
while (index--) {
if (array[index] === value) {
return index;
}
}
return index;
}
/**
* Gets the number of symbols in `string`.
*
* @private
* @param {string} string The string to inspect.
* @returns {number} Returns the string size.
*/
function stringSize(string) {
return hasUnicode(string)
? unicodeSize(string)
: asciiSize(string);
}
/**
* Converts `string` to an array.
*
* @private
* @param {string} string The string to convert.
* @returns {Array} Returns the converted array.
*/
function stringToArray(string) {
return hasUnicode(string)
? unicodeToArray(string)
: asciiToArray(string);
}
/**
* Used by `_.unescape` to convert HTML entities to characters.
*
* @private
* @param {string} chr The matched character to unescape.
* @returns {string} Returns the unescaped character.
*/
var unescapeHtmlChar = basePropertyOf(htmlUnescapes);
/**
* Gets the size of a Unicode `string`.
*
* @private
* @param {string} string The string inspect.
* @returns {number} Returns the string size.
*/
function unicodeSize(string) {
var result = reUnicode.lastIndex = 0;
while (reUnicode.test(string)) {
++result;
}
return result;
}
/**
* Converts a Unicode `string` to an array.
*
* @private
* @param {string} string The string to convert.
* @returns {Array} Returns the converted array.
*/
function unicodeToArray(string) {
return string.match(reUnicode) || [];
}
/**
* Splits a Unicode `string` into an array of its words.
*
* @private
* @param {string} The string to inspect.
* @returns {Array} Returns the words of `string`.
*/
function unicodeWords(string) {
return string.match(reUnicodeWord) || [];
}