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Upgrade underscore

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commit f66560c9c708646aef5901871daa551e8b95057a 1 parent 4fda7a5
@spicyj spicyj authored
Showing with 598 additions and 330 deletions.
  1. +598 −330 utils/underscore.js
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928 utils/underscore.js
@@ -1,10 +1,7 @@
-// Underscore.js 1.2.1
-// (c) 2011 Jeremy Ashkenas, DocumentCloud Inc.
-// Underscore is freely distributable under the MIT license.
-// Portions of Underscore are inspired or borrowed from Prototype,
-// Oliver Steele's Functional, and John Resig's Micro-Templating.
-// For all details and documentation:
-// http://documentcloud.github.com/underscore
+// Underscore.js 1.4.4
+// http://underscorejs.org
+// (c) 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
+// Underscore may be freely distributed under the MIT license.
(function() {
@@ -24,8 +21,9 @@
var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
// Create quick reference variables for speed access to core prototypes.
- var slice = ArrayProto.slice,
- unshift = ArrayProto.unshift,
+ var push = ArrayProto.push,
+ slice = ArrayProto.slice,
+ concat = ArrayProto.concat,
toString = ObjProto.toString,
hasOwnProperty = ObjProto.hasOwnProperty;
@@ -46,28 +44,27 @@
nativeBind = FuncProto.bind;
// Create a safe reference to the Underscore object for use below.
- var _ = function(obj) { return new wrapper(obj); };
+ var _ = function(obj) {
+ if (obj instanceof _) return obj;
+ if (!(this instanceof _)) return new _(obj);
+ this._wrapped = obj;
+ };
- // Export the Underscore object for **Node.js** and **"CommonJS"**, with
- // backwards-compatibility for the old `require()` API. If we're not in
- // CommonJS, add `_` to the global object.
+ // Export the Underscore object for **Node.js**, with
+ // backwards-compatibility for the old `require()` API. If we're in
+ // the browser, add `_` as a global object via a string identifier,
+ // for Closure Compiler "advanced" mode.
if (typeof exports !== 'undefined') {
if (typeof module !== 'undefined' && module.exports) {
exports = module.exports = _;
}
exports._ = _;
- } else if (typeof define === 'function' && define.amd) {
- // Register as a named module with AMD.
- define('underscore', function() {
- return _;
- });
} else {
- // Exported as a string, for Closure Compiler "advanced" mode.
- root['_'] = _;
+ root._ = _;
}
// Current version.
- _.VERSION = '1.2.1';
+ _.VERSION = '1.4.4';
// Collection Functions
// --------------------
@@ -81,11 +78,11 @@
obj.forEach(iterator, context);
} else if (obj.length === +obj.length) {
for (var i = 0, l = obj.length; i < l; i++) {
- if (i in obj && iterator.call(context, obj[i], i, obj) === breaker) return;
+ if (iterator.call(context, obj[i], i, obj) === breaker) return;
}
} else {
for (var key in obj) {
- if (hasOwnProperty.call(obj, key)) {
+ if (_.has(obj, key)) {
if (iterator.call(context, obj[key], key, obj) === breaker) return;
}
}
@@ -94,7 +91,7 @@
// Return the results of applying the iterator to each element.
// Delegates to **ECMAScript 5**'s native `map` if available.
- _.map = function(obj, iterator, context) {
+ _.map = _.collect = function(obj, iterator, context) {
var results = [];
if (obj == null) return results;
if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);
@@ -104,10 +101,12 @@
return results;
};
+ var reduceError = 'Reduce of empty array with no initial value';
+
// **Reduce** builds up a single result from a list of values, aka `inject`,
// or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available.
_.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) {
- var initial = memo !== void 0;
+ var initial = arguments.length > 2;
if (obj == null) obj = [];
if (nativeReduce && obj.reduce === nativeReduce) {
if (context) iterator = _.bind(iterator, context);
@@ -121,20 +120,35 @@
memo = iterator.call(context, memo, value, index, list);
}
});
- if (!initial) throw new TypeError("Reduce of empty array with no initial value");
+ if (!initial) throw new TypeError(reduceError);
return memo;
};
// The right-associative version of reduce, also known as `foldr`.
// Delegates to **ECMAScript 5**'s native `reduceRight` if available.
_.reduceRight = _.foldr = function(obj, iterator, memo, context) {
+ var initial = arguments.length > 2;
if (obj == null) obj = [];
if (nativeReduceRight && obj.reduceRight === nativeReduceRight) {
if (context) iterator = _.bind(iterator, context);
- return memo !== void 0 ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
+ return initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
}
- var reversed = (_.isArray(obj) ? obj.slice() : _.toArray(obj)).reverse();
- return _.reduce(reversed, iterator, memo, context);
+ var length = obj.length;
+ if (length !== +length) {
+ var keys = _.keys(obj);
+ length = keys.length;
+ }
+ each(obj, function(value, index, list) {
+ index = keys ? keys[--length] : --length;
+ if (!initial) {
+ memo = obj[index];
+ initial = true;
+ } else {
+ memo = iterator.call(context, memo, obj[index], index, list);
+ }
+ });
+ if (!initial) throw new TypeError(reduceError);
+ return memo;
};
// Return the first value which passes a truth test. Aliased as `detect`.
@@ -164,58 +178,55 @@
// Return all the elements for which a truth test fails.
_.reject = function(obj, iterator, context) {
- var results = [];
- if (obj == null) return results;
- each(obj, function(value, index, list) {
- if (!iterator.call(context, value, index, list)) results[results.length] = value;
- });
- return results;
+ return _.filter(obj, function(value, index, list) {
+ return !iterator.call(context, value, index, list);
+ }, context);
};
// Determine whether all of the elements match a truth test.
// Delegates to **ECMAScript 5**'s native `every` if available.
// Aliased as `all`.
_.every = _.all = function(obj, iterator, context) {
+ iterator || (iterator = _.identity);
var result = true;
if (obj == null) return result;
if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
each(obj, function(value, index, list) {
if (!(result = result && iterator.call(context, value, index, list))) return breaker;
});
- return result;
+ return !!result;
};
// Determine if at least one element in the object matches a truth test.
// Delegates to **ECMAScript 5**'s native `some` if available.
// Aliased as `any`.
var any = _.some = _.any = function(obj, iterator, context) {
- iterator = iterator || _.identity;
+ iterator || (iterator = _.identity);
var result = false;
if (obj == null) return result;
if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
each(obj, function(value, index, list) {
- if (result |= iterator.call(context, value, index, list)) return breaker;
+ if (result || (result = iterator.call(context, value, index, list))) return breaker;
});
return !!result;
};
- // Determine if a given value is included in the array or object using `===`.
- // Aliased as `contains`.
- _.include = _.contains = function(obj, target) {
- var found = false;
- if (obj == null) return found;
+ // Determine if the array or object contains a given value (using `===`).
+ // Aliased as `include`.
+ _.contains = _.include = function(obj, target) {
+ if (obj == null) return false;
if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
- found = any(obj, function(value) {
- if (value === target) return true;
+ return any(obj, function(value) {
+ return value === target;
});
- return found;
};
// Invoke a method (with arguments) on every item in a collection.
_.invoke = function(obj, method) {
var args = slice.call(arguments, 2);
+ var isFunc = _.isFunction(method);
return _.map(obj, function(value) {
- return (method.call ? method || value : value[method]).apply(value, args);
+ return (isFunc ? method : value[method]).apply(value, args);
});
};
@@ -224,11 +235,33 @@
return _.map(obj, function(value){ return value[key]; });
};
+ // Convenience version of a common use case of `filter`: selecting only objects
+ // containing specific `key:value` pairs.
+ _.where = function(obj, attrs, first) {
+ if (_.isEmpty(attrs)) return first ? null : [];
+ return _[first ? 'find' : 'filter'](obj, function(value) {
+ for (var key in attrs) {
+ if (attrs[key] !== value[key]) return false;
+ }
+ return true;
+ });
+ };
+
+ // Convenience version of a common use case of `find`: getting the first object
+ // containing specific `key:value` pairs.
+ _.findWhere = function(obj, attrs) {
+ return _.where(obj, attrs, true);
+ };
+
// Return the maximum element or (element-based computation).
+ // Can't optimize arrays of integers longer than 65,535 elements.
+ // See: https://bugs.webkit.org/show_bug.cgi?id=80797
_.max = function(obj, iterator, context) {
- if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
+ if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
+ return Math.max.apply(Math, obj);
+ }
if (!iterator && _.isEmpty(obj)) return -Infinity;
- var result = {computed : -Infinity};
+ var result = {computed : -Infinity, value: -Infinity};
each(obj, function(value, index, list) {
var computed = iterator ? iterator.call(context, value, index, list) : value;
computed >= result.computed && (result = {value : value, computed : computed});
@@ -238,9 +271,11 @@
// Return the minimum element (or element-based computation).
_.min = function(obj, iterator, context) {
- if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
+ if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
+ return Math.min.apply(Math, obj);
+ }
if (!iterator && _.isEmpty(obj)) return Infinity;
- var result = {computed : Infinity};
+ var result = {computed : Infinity, value: Infinity};
each(obj, function(value, index, list) {
var computed = iterator ? iterator.call(context, value, index, list) : value;
computed < result.computed && (result = {value : value, computed : computed});
@@ -250,81 +285,110 @@
// Shuffle an array.
_.shuffle = function(obj) {
- var shuffled = [], rand;
- each(obj, function(value, index, list) {
- if (index == 0) {
- shuffled[0] = value;
- } else {
- rand = Math.floor(Math.random() * (index + 1));
- shuffled[index] = shuffled[rand];
- shuffled[rand] = value;
- }
+ var rand;
+ var index = 0;
+ var shuffled = [];
+ each(obj, function(value) {
+ rand = _.random(index++);
+ shuffled[index - 1] = shuffled[rand];
+ shuffled[rand] = value;
});
return shuffled;
};
+ // An internal function to generate lookup iterators.
+ var lookupIterator = function(value) {
+ return _.isFunction(value) ? value : function(obj){ return obj[value]; };
+ };
+
// Sort the object's values by a criterion produced by an iterator.
- _.sortBy = function(obj, iterator, context) {
+ _.sortBy = function(obj, value, context) {
+ var iterator = lookupIterator(value);
return _.pluck(_.map(obj, function(value, index, list) {
return {
value : value,
+ index : index,
criteria : iterator.call(context, value, index, list)
};
}).sort(function(left, right) {
- var a = left.criteria, b = right.criteria;
- return a < b ? -1 : a > b ? 1 : 0;
+ var a = left.criteria;
+ var b = right.criteria;
+ if (a !== b) {
+ if (a > b || a === void 0) return 1;
+ if (a < b || b === void 0) return -1;
+ }
+ return left.index < right.index ? -1 : 1;
}), 'value');
};
- // Groups the object's values by a criterion. Pass either a string attribute
- // to group by, or a function that returns the criterion.
- _.groupBy = function(obj, val) {
+ // An internal function used for aggregate "group by" operations.
+ var group = function(obj, value, context, behavior) {
var result = {};
- var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; };
+ var iterator = lookupIterator(value || _.identity);
each(obj, function(value, index) {
- var key = iterator(value, index);
- (result[key] || (result[key] = [])).push(value);
+ var key = iterator.call(context, value, index, obj);
+ behavior(result, key, value);
});
return result;
};
- // Use a comparator function to figure out at what index an object should
- // be inserted so as to maintain order. Uses binary search.
- _.sortedIndex = function(array, obj, iterator) {
- iterator || (iterator = _.identity);
+ // Groups the object's values by a criterion. Pass either a string attribute
+ // to group by, or a function that returns the criterion.
+ _.groupBy = function(obj, value, context) {
+ return group(obj, value, context, function(result, key, value) {
+ (_.has(result, key) ? result[key] : (result[key] = [])).push(value);
+ });
+ };
+
+ // Counts instances of an object that group by a certain criterion. Pass
+ // either a string attribute to count by, or a function that returns the
+ // criterion.
+ _.countBy = function(obj, value, context) {
+ return group(obj, value, context, function(result, key) {
+ if (!_.has(result, key)) result[key] = 0;
+ result[key]++;
+ });
+ };
+
+ // Use a comparator function to figure out the smallest index at which
+ // an object should be inserted so as to maintain order. Uses binary search.
+ _.sortedIndex = function(array, obj, iterator, context) {
+ iterator = iterator == null ? _.identity : lookupIterator(iterator);
+ var value = iterator.call(context, obj);
var low = 0, high = array.length;
while (low < high) {
- var mid = (low + high) >> 1;
- iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid;
+ var mid = (low + high) >>> 1;
+ iterator.call(context, array[mid]) < value ? low = mid + 1 : high = mid;
}
return low;
};
// Safely convert anything iterable into a real, live array.
- _.toArray = function(iterable) {
- if (!iterable) return [];
- if (iterable.toArray) return iterable.toArray();
- if (_.isArray(iterable)) return slice.call(iterable);
- if (_.isArguments(iterable)) return slice.call(iterable);
- return _.values(iterable);
+ _.toArray = function(obj) {
+ if (!obj) return [];
+ if (_.isArray(obj)) return slice.call(obj);
+ if (obj.length === +obj.length) return _.map(obj, _.identity);
+ return _.values(obj);
};
// Return the number of elements in an object.
_.size = function(obj) {
- return _.toArray(obj).length;
+ if (obj == null) return 0;
+ return (obj.length === +obj.length) ? obj.length : _.keys(obj).length;
};
// Array Functions
// ---------------
// Get the first element of an array. Passing **n** will return the first N
- // values in the array. Aliased as `head`. The **guard** check allows it to work
- // with `_.map`.
- _.first = _.head = function(array, n, guard) {
+ // values in the array. Aliased as `head` and `take`. The **guard** check
+ // allows it to work with `_.map`.
+ _.first = _.head = _.take = function(array, n, guard) {
+ if (array == null) return void 0;
return (n != null) && !guard ? slice.call(array, 0, n) : array[0];
};
- // Returns everything but the last entry of the array. Especcialy useful on
+ // Returns everything but the last entry of the array. Especially useful on
// the arguments object. Passing **n** will return all the values in
// the array, excluding the last N. The **guard** check allows it to work with
// `_.map`.
@@ -335,29 +399,42 @@
// Get the last element of an array. Passing **n** will return the last N
// values in the array. The **guard** check allows it to work with `_.map`.
_.last = function(array, n, guard) {
- return (n != null) && !guard ? slice.call(array, array.length - n) : array[array.length - 1];
+ if (array == null) return void 0;
+ if ((n != null) && !guard) {
+ return slice.call(array, Math.max(array.length - n, 0));
+ } else {
+ return array[array.length - 1];
+ }
};
- // Returns everything but the first entry of the array. Aliased as `tail`.
- // Especially useful on the arguments object. Passing an **index** will return
- // the rest of the values in the array from that index onward. The **guard**
+ // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
+ // Especially useful on the arguments object. Passing an **n** will return
+ // the rest N values in the array. The **guard**
// check allows it to work with `_.map`.
- _.rest = _.tail = function(array, index, guard) {
- return slice.call(array, (index == null) || guard ? 1 : index);
+ _.rest = _.tail = _.drop = function(array, n, guard) {
+ return slice.call(array, (n == null) || guard ? 1 : n);
};
// Trim out all falsy values from an array.
_.compact = function(array) {
- return _.filter(array, function(value){ return !!value; });
+ return _.filter(array, _.identity);
+ };
+
+ // Internal implementation of a recursive `flatten` function.
+ var flatten = function(input, shallow, output) {
+ each(input, function(value) {
+ if (_.isArray(value)) {
+ shallow ? push.apply(output, value) : flatten(value, shallow, output);
+ } else {
+ output.push(value);
+ }
+ });
+ return output;
};
// Return a completely flattened version of an array.
_.flatten = function(array, shallow) {
- return _.reduce(array, function(memo, value) {
- if (_.isArray(value)) return memo.concat(shallow ? value : _.flatten(value));
- memo[memo.length] = value;
- return memo;
- }, []);
+ return flatten(array, shallow, []);
};
// Return a version of the array that does not contain the specified value(s).
@@ -368,28 +445,33 @@
// Produce a duplicate-free version of the array. If the array has already
// been sorted, you have the option of using a faster algorithm.
// Aliased as `unique`.
- _.uniq = _.unique = function(array, isSorted, iterator) {
- var initial = iterator ? _.map(array, iterator) : array;
- var result = [];
- _.reduce(initial, function(memo, el, i) {
- if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) {
- memo[memo.length] = el;
- result[result.length] = array[i];
+ _.uniq = _.unique = function(array, isSorted, iterator, context) {
+ if (_.isFunction(isSorted)) {
+ context = iterator;
+ iterator = isSorted;
+ isSorted = false;
+ }
+ var initial = iterator ? _.map(array, iterator, context) : array;
+ var results = [];
+ var seen = [];
+ each(initial, function(value, index) {
+ if (isSorted ? (!index || seen[seen.length - 1] !== value) : !_.contains(seen, value)) {
+ seen.push(value);
+ results.push(array[index]);
}
- return memo;
- }, []);
- return result;
+ });
+ return results;
};
// Produce an array that contains the union: each distinct element from all of
// the passed-in arrays.
_.union = function() {
- return _.uniq(_.flatten(arguments, true));
+ return _.uniq(concat.apply(ArrayProto, arguments));
};
// Produce an array that contains every item shared between all the
- // passed-in arrays. (Aliased as "intersect" for back-compat.)
- _.intersection = _.intersect = function(array) {
+ // passed-in arrays.
+ _.intersection = function(array) {
var rest = slice.call(arguments, 1);
return _.filter(_.uniq(array), function(item) {
return _.every(rest, function(other) {
@@ -398,10 +480,11 @@
});
};
- // Take the difference between one array and another.
+ // Take the difference between one array and a number of other arrays.
// Only the elements present in just the first array will remain.
- _.difference = function(array, other) {
- return _.filter(array, function(value){ return !_.include(other, value); });
+ _.difference = function(array) {
+ var rest = concat.apply(ArrayProto, slice.call(arguments, 1));
+ return _.filter(array, function(value){ return !_.contains(rest, value); });
};
// Zip together multiple lists into a single array -- elements that share
@@ -410,10 +493,28 @@
var args = slice.call(arguments);
var length = _.max(_.pluck(args, 'length'));
var results = new Array(length);
- for (var i = 0; i < length; i++) results[i] = _.pluck(args, "" + i);
+ for (var i = 0; i < length; i++) {
+ results[i] = _.pluck(args, "" + i);
+ }
return results;
};
+ // Converts lists into objects. Pass either a single array of `[key, value]`
+ // pairs, or two parallel arrays of the same length -- one of keys, and one of
+ // the corresponding values.
+ _.object = function(list, values) {
+ if (list == null) return {};
+ var result = {};
+ for (var i = 0, l = list.length; i < l; i++) {
+ if (values) {
+ result[list[i]] = values[i];
+ } else {
+ result[list[i][0]] = list[i][1];
+ }
+ }
+ return result;
+ };
+
// If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**),
// we need this function. Return the position of the first occurrence of an
// item in an array, or -1 if the item is not included in the array.
@@ -422,21 +523,28 @@
// for **isSorted** to use binary search.
_.indexOf = function(array, item, isSorted) {
if (array == null) return -1;
- var i, l;
+ var i = 0, l = array.length;
if (isSorted) {
- i = _.sortedIndex(array, item);
- return array[i] === item ? i : -1;
+ if (typeof isSorted == 'number') {
+ i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted);
+ } else {
+ i = _.sortedIndex(array, item);
+ return array[i] === item ? i : -1;
+ }
}
- if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item);
- for (i = 0, l = array.length; i < l; i++) if (array[i] === item) return i;
+ if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted);
+ for (; i < l; i++) if (array[i] === item) return i;
return -1;
};
// Delegates to **ECMAScript 5**'s native `lastIndexOf` if available.
- _.lastIndexOf = function(array, item) {
+ _.lastIndexOf = function(array, item, from) {
if (array == null) return -1;
- if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item);
- var i = array.length;
+ var hasIndex = from != null;
+ if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) {
+ return hasIndex ? array.lastIndexOf(item, from) : array.lastIndexOf(item);
+ }
+ var i = (hasIndex ? from : array.length);
while (i--) if (array[i] === item) return i;
return -1;
};
@@ -466,25 +574,23 @@
// Function (ahem) Functions
// ------------------
- // Reusable constructor function for prototype setting.
- var ctor = function(){};
-
// Create a function bound to a given object (assigning `this`, and arguments,
- // optionally). Binding with arguments is also known as `curry`.
- // Delegates to **ECMAScript 5**'s native `Function.bind` if available.
- // We check for `func.bind` first, to fail fast when `func` is undefined.
- _.bind = function bind(func, context) {
- var bound, args;
+ // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
+ // available.
+ _.bind = function(func, context) {
if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
- if (!_.isFunction(func)) throw new TypeError;
- args = slice.call(arguments, 2);
- return bound = function() {
- if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments)));
- ctor.prototype = func.prototype;
- var self = new ctor;
- var result = func.apply(self, args.concat(slice.call(arguments)));
- if (Object(result) === result) return result;
- return self;
+ var args = slice.call(arguments, 2);
+ return function() {
+ return func.apply(context, args.concat(slice.call(arguments)));
+ };
+ };
+
+ // Partially apply a function by creating a version that has had some of its
+ // arguments pre-filled, without changing its dynamic `this` context.
+ _.partial = function(func) {
+ var args = slice.call(arguments, 1);
+ return function() {
+ return func.apply(this, args.concat(slice.call(arguments)));
};
};
@@ -492,7 +598,7 @@
// all callbacks defined on an object belong to it.
_.bindAll = function(obj) {
var funcs = slice.call(arguments, 1);
- if (funcs.length == 0) funcs = _.functions(obj);
+ if (funcs.length === 0) funcs = _.functions(obj);
each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
return obj;
};
@@ -503,7 +609,7 @@
hasher || (hasher = _.identity);
return function() {
var key = hasher.apply(this, arguments);
- return hasOwnProperty.call(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
+ return _.has(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
};
};
@@ -511,7 +617,7 @@
// it with the arguments supplied.
_.delay = function(func, wait) {
var args = slice.call(arguments, 2);
- return setTimeout(function(){ return func.apply(func, args); }, wait);
+ return setTimeout(function(){ return func.apply(null, args); }, wait);
};
// Defers a function, scheduling it to run after the current call stack has
@@ -523,35 +629,47 @@
// Returns a function, that, when invoked, will only be triggered at most once
// during a given window of time.
_.throttle = function(func, wait) {
- var timeout, context, args, throttling, finishThrottle;
- finishThrottle = _.debounce(function(){ throttling = false; }, wait);
+ var context, args, timeout, result;
+ var previous = 0;
+ var later = function() {
+ previous = new Date;
+ timeout = null;
+ result = func.apply(context, args);
+ };
return function() {
- context = this; args = arguments;
- var throttler = function() {
+ var now = new Date;
+ var remaining = wait - (now - previous);
+ context = this;
+ args = arguments;
+ if (remaining <= 0) {
+ clearTimeout(timeout);
timeout = null;
- func.apply(context, args);
- finishThrottle();
- };
- if (!timeout) timeout = setTimeout(throttler, wait);
- if (!throttling) func.apply(context, args);
- if (finishThrottle) finishThrottle();
- throttling = true;
+ previous = now;
+ result = func.apply(context, args);
+ } else if (!timeout) {
+ timeout = setTimeout(later, remaining);
+ }
+ return result;
};
};
// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
- // N milliseconds.
- _.debounce = function(func, wait) {
- var timeout;
+ // N milliseconds. If `immediate` is passed, trigger the function on the
+ // leading edge, instead of the trailing.
+ _.debounce = function(func, wait, immediate) {
+ var timeout, result;
return function() {
var context = this, args = arguments;
- var throttler = function() {
+ var later = function() {
timeout = null;
- func.apply(context, args);
+ if (!immediate) result = func.apply(context, args);
};
+ var callNow = immediate && !timeout;
clearTimeout(timeout);
- timeout = setTimeout(throttler, wait);
+ timeout = setTimeout(later, wait);
+ if (callNow) result = func.apply(context, args);
+ return result;
};
};
@@ -562,7 +680,9 @@
return function() {
if (ran) return memo;
ran = true;
- return memo = func.apply(this, arguments);
+ memo = func.apply(this, arguments);
+ func = null;
+ return memo;
};
};
@@ -571,7 +691,8 @@
// conditionally execute the original function.
_.wrap = function(func, wrapper) {
return function() {
- var args = [func].concat(slice.call(arguments));
+ var args = [func];
+ push.apply(args, arguments);
return wrapper.apply(this, args);
};
};
@@ -579,9 +700,9 @@
// Returns a function that is the composition of a list of functions, each
// consuming the return value of the function that follows.
_.compose = function() {
- var funcs = slice.call(arguments);
+ var funcs = arguments;
return function() {
- var args = slice.call(arguments);
+ var args = arguments;
for (var i = funcs.length - 1; i >= 0; i--) {
args = [funcs[i].apply(this, args)];
}
@@ -591,8 +712,11 @@
// Returns a function that will only be executed after being called N times.
_.after = function(times, func) {
+ if (times <= 0) return func();
return function() {
- if (--times < 1) { return func.apply(this, arguments); }
+ if (--times < 1) {
+ return func.apply(this, arguments);
+ }
};
};
@@ -604,13 +728,29 @@
_.keys = nativeKeys || function(obj) {
if (obj !== Object(obj)) throw new TypeError('Invalid object');
var keys = [];
- for (var key in obj) if (hasOwnProperty.call(obj, key)) keys[keys.length] = key;
+ for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key;
return keys;
};
// Retrieve the values of an object's properties.
_.values = function(obj) {
- return _.map(obj, _.identity);
+ var values = [];
+ for (var key in obj) if (_.has(obj, key)) values.push(obj[key]);
+ return values;
+ };
+
+ // Convert an object into a list of `[key, value]` pairs.
+ _.pairs = function(obj) {
+ var pairs = [];
+ for (var key in obj) if (_.has(obj, key)) pairs.push([key, obj[key]]);
+ return pairs;
+ };
+
+ // Invert the keys and values of an object. The values must be serializable.
+ _.invert = function(obj) {
+ var result = {};
+ for (var key in obj) if (_.has(obj, key)) result[obj[key]] = key;
+ return result;
};
// Return a sorted list of the function names available on the object.
@@ -626,18 +766,42 @@
// Extend a given object with all the properties in passed-in object(s).
_.extend = function(obj) {
each(slice.call(arguments, 1), function(source) {
- for (var prop in source) {
- if (source[prop] !== void 0) obj[prop] = source[prop];
+ if (source) {
+ for (var prop in source) {
+ obj[prop] = source[prop];
+ }
}
});
return obj;
};
+ // Return a copy of the object only containing the whitelisted properties.
+ _.pick = function(obj) {
+ var copy = {};
+ var keys = concat.apply(ArrayProto, slice.call(arguments, 1));
+ each(keys, function(key) {
+ if (key in obj) copy[key] = obj[key];
+ });
+ return copy;
+ };
+
+ // Return a copy of the object without the blacklisted properties.
+ _.omit = function(obj) {
+ var copy = {};
+ var keys = concat.apply(ArrayProto, slice.call(arguments, 1));
+ for (var key in obj) {
+ if (!_.contains(keys, key)) copy[key] = obj[key];
+ }
+ return copy;
+ };
+
// Fill in a given object with default properties.
_.defaults = function(obj) {
each(slice.call(arguments, 1), function(source) {
- for (var prop in source) {
- if (obj[prop] == null) obj[prop] = source[prop];
+ if (source) {
+ for (var prop in source) {
+ if (obj[prop] == null) obj[prop] = source[prop];
+ }
}
});
return obj;
@@ -657,102 +821,114 @@
return obj;
};
- // Internal recursive comparison function.
- function eq(a, b, stack) {
+ // Internal recursive comparison function for `isEqual`.
+ var eq = function(a, b, aStack, bStack) {
// Identical objects are equal. `0 === -0`, but they aren't identical.
// See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.
if (a === b) return a !== 0 || 1 / a == 1 / b;
// A strict comparison is necessary because `null == undefined`.
- if ((a == null) || (b == null)) return a === b;
+ if (a == null || b == null) return a === b;
// Unwrap any wrapped objects.
- if (a._chain) a = a._wrapped;
- if (b._chain) b = b._wrapped;
- // Invoke a custom `isEqual` method if one is provided.
- if (_.isFunction(a.isEqual)) return a.isEqual(b);
- if (_.isFunction(b.isEqual)) return b.isEqual(a);
- // Compare object types.
- var typeA = typeof a;
- if (typeA != typeof b) return false;
- // Optimization; ensure that both values are truthy or falsy.
- if (!a != !b) return false;
- // `NaN` values are equal.
- if (_.isNaN(a)) return _.isNaN(b);
- // Compare string objects by value.
- var isStringA = _.isString(a), isStringB = _.isString(b);
- if (isStringA || isStringB) return isStringA && isStringB && String(a) == String(b);
- // Compare number objects by value.
- var isNumberA = _.isNumber(a), isNumberB = _.isNumber(b);
- if (isNumberA || isNumberB) return isNumberA && isNumberB && +a == +b;
- // Compare boolean objects by value. The value of `true` is 1; the value of `false` is 0.
- var isBooleanA = _.isBoolean(a), isBooleanB = _.isBoolean(b);
- if (isBooleanA || isBooleanB) return isBooleanA && isBooleanB && +a == +b;
- // Compare dates by their millisecond values.
- var isDateA = _.isDate(a), isDateB = _.isDate(b);
- if (isDateA || isDateB) return isDateA && isDateB && a.getTime() == b.getTime();
- // Compare RegExps by their source patterns and flags.
- var isRegExpA = _.isRegExp(a), isRegExpB = _.isRegExp(b);
- if (isRegExpA || isRegExpB) {
- // Ensure commutative equality for RegExps.
- return isRegExpA && isRegExpB &&
- a.source == b.source &&
- a.global == b.global &&
- a.multiline == b.multiline &&
- a.ignoreCase == b.ignoreCase;
+ if (a instanceof _) a = a._wrapped;
+ if (b instanceof _) b = b._wrapped;
+ // Compare `[[Class]]` names.
+ var className = toString.call(a);
+ if (className != toString.call(b)) return false;
+ switch (className) {
+ // Strings, numbers, dates, and booleans are compared by value.
+ case '[object String]':
+ // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
+ // equivalent to `new String("5")`.
+ return a == String(b);
+ case '[object Number]':
+ // `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for
+ // other numeric values.
+ return a != +a ? b != +b : (a == 0 ? 1 / a == 1 / b : a == +b);
+ case '[object Date]':
+ case '[object Boolean]':
+ // Coerce dates and booleans to numeric primitive values. Dates are compared by their
+ // millisecond representations. Note that invalid dates with millisecond representations
+ // of `NaN` are not equivalent.
+ return +a == +b;
+ // RegExps are compared by their source patterns and flags.
+ case '[object RegExp]':
+ return a.source == b.source &&
+ a.global == b.global &&
+ a.multiline == b.multiline &&
+ a.ignoreCase == b.ignoreCase;
}
- // Ensure that both values are objects.
- if (typeA != 'object') return false;
- // Arrays or Arraylikes with different lengths are not equal.
- if (a.length !== b.length) return false;
- // Objects with different constructors are not equal.
- if (a.constructor !== b.constructor) return false;
+ if (typeof a != 'object' || typeof b != 'object') return false;
// Assume equality for cyclic structures. The algorithm for detecting cyclic
// structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
- var length = stack.length;
+ var length = aStack.length;
while (length--) {
// Linear search. Performance is inversely proportional to the number of
// unique nested structures.
- if (stack[length] == a) return true;
+ if (aStack[length] == a) return bStack[length] == b;
}
// Add the first object to the stack of traversed objects.
- stack.push(a);
+ aStack.push(a);
+ bStack.push(b);
var size = 0, result = true;
- // Deep compare objects.
- for (var key in a) {
- if (hasOwnProperty.call(a, key)) {
- // Count the expected number of properties.
- size++;
- // Deep compare each member.
- if (!(result = hasOwnProperty.call(b, key) && eq(a[key], b[key], stack))) break;
+ // Recursively compare objects and arrays.
+ if (className == '[object Array]') {
+ // Compare array lengths to determine if a deep comparison is necessary.
+ size = a.length;
+ result = size == b.length;
+ if (result) {
+ // Deep compare the contents, ignoring non-numeric properties.
+ while (size--) {
+ if (!(result = eq(a[size], b[size], aStack, bStack))) break;
+ }
}
- }
- // Ensure that both objects contain the same number of properties.
- if (result) {
- for (key in b) {
- if (hasOwnProperty.call(b, key) && !size--) break;
+ } else {
+ // Objects with different constructors are not equivalent, but `Object`s
+ // from different frames are.
+ var aCtor = a.constructor, bCtor = b.constructor;
+ if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) &&
+ _.isFunction(bCtor) && (bCtor instanceof bCtor))) {
+ return false;
+ }
+ // Deep compare objects.
+ for (var key in a) {
+ if (_.has(a, key)) {
+ // Count the expected number of properties.
+ size++;
+ // Deep compare each member.
+ if (!(result = _.has(b, key) && eq(a[key], b[key], aStack, bStack))) break;
+ }
+ }
+ // Ensure that both objects contain the same number of properties.
+ if (result) {
+ for (key in b) {
+ if (_.has(b, key) && !(size--)) break;
+ }
+ result = !size;
}
- result = !size;
}
// Remove the first object from the stack of traversed objects.
- stack.pop();
+ aStack.pop();
+ bStack.pop();
return result;
- }
+ };
// Perform a deep comparison to check if two objects are equal.
_.isEqual = function(a, b) {
- return eq(a, b, []);
+ return eq(a, b, [], []);
};
// Is a given array, string, or object empty?
// An "empty" object has no enumerable own-properties.
_.isEmpty = function(obj) {
+ if (obj == null) return true;
if (_.isArray(obj) || _.isString(obj)) return obj.length === 0;
- for (var key in obj) if (hasOwnProperty.call(obj, key)) return false;
+ for (var key in obj) if (_.has(obj, key)) return false;
return true;
};
// Is a given value a DOM element?
_.isElement = function(obj) {
- return !!(obj && obj.nodeType == 1);
+ return !!(obj && obj.nodeType === 1);
};
// Is a given value an array?
@@ -766,36 +942,36 @@
return obj === Object(obj);
};
- // Is a given variable an arguments object?
- if (toString.call(arguments) == '[object Arguments]') {
- _.isArguments = function(obj) {
- return toString.call(obj) == '[object Arguments]';
+ // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp.
+ each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp'], function(name) {
+ _['is' + name] = function(obj) {
+ return toString.call(obj) == '[object ' + name + ']';
};
- } else {
+ });
+
+ // Define a fallback version of the method in browsers (ahem, IE), where
+ // there isn't any inspectable "Arguments" type.
+ if (!_.isArguments(arguments)) {
_.isArguments = function(obj) {
- return !!(obj && hasOwnProperty.call(obj, 'callee'));
+ return !!(obj && _.has(obj, 'callee'));
};
}
- // Is a given value a function?
- _.isFunction = function(obj) {
- return toString.call(obj) == '[object Function]';
- };
-
- // Is a given value a string?
- _.isString = function(obj) {
- return toString.call(obj) == '[object String]';
- };
+ // Optimize `isFunction` if appropriate.
+ if (typeof (/./) !== 'function') {
+ _.isFunction = function(obj) {
+ return typeof obj === 'function';
+ };
+ }
- // Is a given value a number?
- _.isNumber = function(obj) {
- return toString.call(obj) == '[object Number]';
+ // Is a given object a finite number?
+ _.isFinite = function(obj) {
+ return isFinite(obj) && !isNaN(parseFloat(obj));
};
- // Is the given value `NaN`?
+ // Is the given value `NaN`? (NaN is the only number which does not equal itself).
_.isNaN = function(obj) {
- // `NaN` is the only value for which `===` is not reflexive.
- return obj !== obj;
+ return _.isNumber(obj) && obj != +obj;
};
// Is a given value a boolean?
@@ -803,16 +979,6 @@
return obj === true || obj === false || toString.call(obj) == '[object Boolean]';
};
- // Is a given value a date?
- _.isDate = function(obj) {
- return toString.call(obj) == '[object Date]';
- };
-
- // Is the given value a regular expression?
- _.isRegExp = function(obj) {
- return toString.call(obj) == '[object RegExp]';
- };
-
// Is a given value equal to null?
_.isNull = function(obj) {
return obj === null;
@@ -823,6 +989,12 @@
return obj === void 0;
};
+ // Shortcut function for checking if an object has a given property directly
+ // on itself (in other words, not on a prototype).
+ _.has = function(obj, key) {
+ return hasOwnProperty.call(obj, key);
+ };
+
// Utility Functions
// -----------------
@@ -839,20 +1011,67 @@
};
// Run a function **n** times.
- _.times = function (n, iterator, context) {
- for (var i = 0; i < n; i++) iterator.call(context, i);
+ _.times = function(n, iterator, context) {
+ var accum = Array(n);
+ for (var i = 0; i < n; i++) accum[i] = iterator.call(context, i);
+ return accum;
+ };
+
+ // Return a random integer between min and max (inclusive).
+ _.random = function(min, max) {
+ if (max == null) {
+ max = min;
+ min = 0;
+ }
+ return min + Math.floor(Math.random() * (max - min + 1));
+ };
+
+ // List of HTML entities for escaping.
+ var entityMap = {
+ escape: {
+ '&': '&amp;',
+ '<': '&lt;',
+ '>': '&gt;',
+ '"': '&quot;',
+ "'": '&#x27;',
+ '/': '&#x2F;'
+ }
};
+ entityMap.unescape = _.invert(entityMap.escape);
- // Escape a string for HTML interpolation.
- _.escape = function(string) {
- return (''+string).replace(/&(?!\w+;|#\d+;|#x[\da-f]+;)/gi, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/'/g, '&#x27;').replace(/\//g,'&#x2F;');
+ // Regexes containing the keys and values listed immediately above.
+ var entityRegexes = {
+ escape: new RegExp('[' + _.keys(entityMap.escape).join('') + ']', 'g'),
+ unescape: new RegExp('(' + _.keys(entityMap.unescape).join('|') + ')', 'g')
};
- // Add your own custom functions to the Underscore object, ensuring that
- // they're correctly added to the OOP wrapper as well.
+ // Functions for escaping and unescaping strings to/from HTML interpolation.
+ _.each(['escape', 'unescape'], function(method) {
+ _[method] = function(string) {
+ if (string == null) return '';
+ return ('' + string).replace(entityRegexes[method], function(match) {
+ return entityMap[method][match];
+ });
+ };
+ });
+
+ // If the value of the named property is a function then invoke it;
+ // otherwise, return it.
+ _.result = function(object, property) {
+ if (object == null) return null;
+ var value = object[property];
+ return _.isFunction(value) ? value.call(object) : value;
+ };
+
+ // Add your own custom functions to the Underscore object.
_.mixin = function(obj) {
each(_.functions(obj), function(name){
- addToWrapper(name, _[name] = obj[name]);
+ var func = _[name] = obj[name];
+ _.prototype[name] = function() {
+ var args = [this._wrapped];
+ push.apply(args, arguments);
+ return result.call(this, func.apply(_, args));
+ };
});
};
@@ -860,7 +1079,7 @@
// Useful for temporary DOM ids.
var idCounter = 0;
_.uniqueId = function(prefix) {
- var id = idCounter++;
+ var id = ++idCounter + '';
return prefix ? prefix + id : id;
};
@@ -872,56 +1091,99 @@
escape : /<%-([\s\S]+?)%>/g
};
+ // When customizing `templateSettings`, if you don't want to define an
+ // interpolation, evaluation or escaping regex, we need one that is
+ // guaranteed not to match.
+ var noMatch = /(.)^/;
+
+ // Certain characters need to be escaped so that they can be put into a
+ // string literal.
+ var escapes = {
+ "'": "'",
+ '\\': '\\',
+ '\r': 'r',
+ '\n': 'n',
+ '\t': 't',
+ '\u2028': 'u2028',
+ '\u2029': 'u2029'
+ };
+
+ var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g;
+
// JavaScript micro-templating, similar to John Resig's implementation.
// Underscore templating handles arbitrary delimiters, preserves whitespace,
// and correctly escapes quotes within interpolated code.
- _.template = function(str, data) {
- var c = _.templateSettings;
- var tmpl = 'var __p=[],print=function(){__p.push.apply(__p,arguments);};' +
- 'with(obj||{}){__p.push(\'' +
- str.replace(/\\/g, '\\\\')
- .replace(/'/g, "\\'")
- .replace(c.escape, function(match, code) {
- return "',_.escape(" + code.replace(/\\'/g, "'") + "),'";
- })
- .replace(c.interpolate, function(match, code) {
- return "'," + code.replace(/\\'/g, "'") + ",'";
- })
- .replace(c.evaluate || null, function(match, code) {
- return "');" + code.replace(/\\'/g, "'")
- .replace(/[\r\n\t]/g, ' ') + "__p.push('";
- })
- .replace(/\r/g, '\\r')
- .replace(/\n/g, '\\n')
- .replace(/\t/g, '\\t')
- + "');}return __p.join('');";
- var func = new Function('obj', tmpl);
- return data ? func(data) : func;
- };
-
- // The OOP Wrapper
- // ---------------
+ _.template = function(text, data, settings) {
+ var render;
+ settings = _.defaults({}, settings, _.templateSettings);
+
+ // Combine delimiters into one regular expression via alternation.
+ var matcher = new RegExp([
+ (settings.escape || noMatch).source,
+ (settings.interpolate || noMatch).source,
+ (settings.evaluate || noMatch).source
+ ].join('|') + '|$', 'g');
+
+ // Compile the template source, escaping string literals appropriately.
+ var index = 0;
+ var source = "__p+='";
+ text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
+ source += text.slice(index, offset)
+ .replace(escaper, function(match) { return '\\' + escapes[match]; });
+
+ if (escape) {
+ source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
+ }
+ if (interpolate) {
+ source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
+ }
+ if (evaluate) {
+ source += "';\n" + evaluate + "\n__p+='";
+ }
+ index = offset + match.length;
+ return match;
+ });
+ source += "';\n";
+
+ // If a variable is not specified, place data values in local scope.
+ if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
+ source = "var __t,__p='',__j=Array.prototype.join," +
+ "print=function(){__p+=__j.call(arguments,'');};\n" +
+ source + "return __p;\n";
+
+ try {
+ render = new Function(settings.variable || 'obj', '_', source);
+ } catch (e) {
+ e.source = source;
+ throw e;
+ }
+
+ if (data) return render(data, _);
+ var template = function(data) {
+ return render.call(this, data, _);
+ };
+
+ // Provide the compiled function source as a convenience for precompilation.
+ template.source = 'function(' + (settings.variable || 'obj') + '){\n' + source + '}';
+
+ return template;
+ };
+
+ // Add a "chain" function, which will delegate to the wrapper.
+ _.chain = function(obj) {
+ return _(obj).chain();
+ };
+
+ // OOP
+ // ---------------
// If Underscore is called as a function, it returns a wrapped object that
// can be used OO-style. This wrapper holds altered versions of all the
// underscore functions. Wrapped objects may be chained.
- var wrapper = function(obj) { this._wrapped = obj; };
-
- // Expose `wrapper.prototype` as `_.prototype`
- _.prototype = wrapper.prototype;
// Helper function to continue chaining intermediate results.
- var result = function(obj, chain) {
- return chain ? _(obj).chain() : obj;
- };
-
- // A method to easily add functions to the OOP wrapper.
- var addToWrapper = function(name, func) {
- wrapper.prototype[name] = function() {
- var args = slice.call(arguments);
- unshift.call(args, this._wrapped);
- return result(func.apply(_, args), this._chain);
- };
+ var result = function(obj) {
+ return this._chain ? _(obj).chain() : obj;
};
// Add all of the Underscore functions to the wrapper object.
@@ -930,29 +1192,35 @@
// Add all mutator Array functions to the wrapper.
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
var method = ArrayProto[name];
- wrapper.prototype[name] = function() {
- method.apply(this._wrapped, arguments);
- return result(this._wrapped, this._chain);
+ _.prototype[name] = function() {
+ var obj = this._wrapped;
+ method.apply(obj, arguments);
+ if ((name == 'shift' || name == 'splice') && obj.length === 0) delete obj[0];
+ return result.call(this, obj);
};
});
// Add all accessor Array functions to the wrapper.
each(['concat', 'join', 'slice'], function(name) {
var method = ArrayProto[name];
- wrapper.prototype[name] = function() {
- return result(method.apply(this._wrapped, arguments), this._chain);
+ _.prototype[name] = function() {
+ return result.call(this, method.apply(this._wrapped, arguments));
};
});
- // Start chaining a wrapped Underscore object.
- wrapper.prototype.chain = function() {
- this._chain = true;
- return this;
- };
+ _.extend(_.prototype, {
- // Extracts the result from a wrapped and chained object.
- wrapper.prototype.value = function() {
- return this._wrapped;
- };
+ // Start chaining a wrapped Underscore object.
+ chain: function() {
+ this._chain = true;
+ return this;
+ },
+
+ // Extracts the result from a wrapped and chained object.
+ value: function() {
+ return this._wrapped;
+ }
+
+ });
-})();
+}).call(this);
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