vendor/assets/javascripts/underscore.js in rails-backbone-0.7.2 vs vendor/assets/javascripts/underscore.js in rails-backbone-0.8.0
- old
+ new
@@ -1,12 +1,9 @@
-// Underscore.js 1.3.3
+// Underscore.js 1.4.0
+// http://underscorejs.org
// (c) 2009-2012 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 may be freely distributed under the MIT license.
(function() {
// Baseline setup
// --------------
@@ -22,11 +19,13 @@
// Save bytes in the minified (but not gzipped) version:
var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
// Create quick reference variables for speed access to core prototypes.
- var slice = ArrayProto.slice,
+ var push = ArrayProto.push,
+ slice = ArrayProto.slice,
+ concat = ArrayProto.concat,
unshift = ArrayProto.unshift,
toString = ObjProto.toString,
hasOwnProperty = ObjProto.hasOwnProperty;
// All **ECMAScript 5** native function implementations that we hope to use
@@ -44,11 +43,15 @@
nativeIsArray = Array.isArray,
nativeKeys = Object.keys,
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**, 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.
@@ -60,25 +63,24 @@
} else {
root['_'] = _;
}
// Current version.
- _.VERSION = '1.3.3';
+ _.VERSION = '1.4.0';
// Collection Functions
// --------------------
// The cornerstone, an `each` implementation, aka `forEach`.
// Handles objects with the built-in `forEach`, arrays, and raw objects.
// Delegates to **ECMAScript 5**'s native `forEach` if available.
var each = _.each = _.forEach = function(obj, iterator, context) {
- if (obj == null) return;
if (nativeForEach && obj.forEach === nativeForEach) {
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 (_.has(obj, key)) {
if (iterator.call(context, obj[key], key, obj) === breaker) return;
@@ -89,24 +91,21 @@
// Return the results of applying the iterator to each element.
// Delegates to **ECMAScript 5**'s native `map` if available.
_.map = _.collect = function(obj, iterator, context) {
var results = [];
- if (obj == null) return results;
if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);
each(obj, function(value, index, list) {
results[results.length] = iterator.call(context, value, index, list);
});
- if (obj.length === +obj.length) results.length = obj.length;
return results;
};
// **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 = arguments.length > 2;
- if (obj == null) obj = [];
if (nativeReduce && obj.reduce === nativeReduce) {
if (context) iterator = _.bind(iterator, context);
return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator);
}
each(obj, function(value, index, list) {
@@ -123,18 +122,30 @@
// 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 initial ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
+ return arguments.length > 2 ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
}
- var reversed = _.toArray(obj).reverse();
- if (context && !initial) iterator = _.bind(iterator, context);
- return initial ? _.reduce(reversed, iterator, memo, context) : _.reduce(reversed, iterator);
+ 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('Reduce of empty array with no initial value');
+ return memo;
};
// Return the first value which passes a truth test. Aliased as `detect`.
_.find = _.detect = function(obj, iterator, context) {
var result;
@@ -150,34 +161,32 @@
// Return all the elements that pass a truth test.
// Delegates to **ECMAScript 5**'s native `filter` if available.
// Aliased as `select`.
_.filter = _.select = function(obj, iterator, context) {
var results = [];
- if (obj == null) return results;
if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
each(obj, function(value, index, list) {
if (iterator.call(context, value, index, list)) results[results.length] = value;
});
return results;
};
// 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;
};
// 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;
@@ -187,23 +196,21 @@
// Delegates to **ECMAScript 5**'s native `some` if available.
// Aliased as `any`.
var any = _.some = _.any = function(obj, iterator, context) {
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 || (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) {
+ // Determine if the array or object contains a given value (using `===`).
+ // Aliased as `include`.
+ _.contains = _.include = function(obj, target) {
var found = false;
- if (obj == null) return found;
if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
found = any(obj, function(value) {
return value === target;
});
return found;
@@ -211,22 +218,38 @@
// Invoke a method (with arguments) on every item in a collection.
_.invoke = function(obj, method) {
var args = slice.call(arguments, 2);
return _.map(obj, function(value) {
- return (_.isFunction(method) ? method || value : value[method]).apply(value, args);
+ return (_.isFunction(method) ? method : value[method]).apply(value, args);
});
};
// Convenience version of a common use case of `map`: fetching a property.
_.pluck = function(obj, key) {
return _.map(obj, function(value){ return value[key]; });
};
+ // Convenience version of a common use case of `filter`: selecting only objects
+ // with specific `key:value` pairs.
+ _.where = function(obj, attrs) {
+ if (_.isEmpty(attrs)) return [];
+ return _.filter(obj, function(value) {
+ for (var key in attrs) {
+ if (attrs[key] !== value[key]) return false;
+ }
+ return 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) && obj[0] === +obj[0]) 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};
each(obj, function(value, index, list) {
var computed = iterator ? iterator.call(context, value, index, list) : value;
computed >= result.computed && (result = {value : value, computed : computed});
@@ -234,11 +257,13 @@
return result.value;
};
// Return the minimum element (or element-based computation).
_.min = function(obj, iterator, context) {
- if (!iterator && _.isArray(obj) && obj[0] === +obj[0]) 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};
each(obj, function(value, index, list) {
var computed = iterator ? iterator.call(context, value, index, list) : value;
computed < result.computed && (result = {value : value, computed : computed});
@@ -246,71 +271,98 @@
return result.value;
};
// Shuffle an array.
_.shuffle = function(obj) {
- var shuffled = [], rand;
- each(obj, function(value, index, list) {
- rand = Math.floor(Math.random() * (index + 1));
- shuffled[index] = shuffled[rand];
+ 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, val, context) {
- var iterator = _.isFunction(val) ? val : function(obj) { return obj[val]; };
+ _.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;
- if (a === void 0) return 1;
- if (b === void 0) return -1;
- 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);
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, value) {
+ 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(obj) {
- if (!obj) return [];
- if (_.isArray(obj)) return slice.call(obj);
- if (_.isArguments(obj)) return slice.call(obj);
- if (obj.toArray && _.isFunction(obj.toArray)) return obj.toArray();
+ if (!obj) return [];
+ if (obj.length === +obj.length) return slice.call(obj);
return _.values(obj);
};
// Return the number of elements in an object.
_.size = function(obj) {
- return _.isArray(obj) ? obj.length : _.keys(obj).length;
+ return (obj.length === +obj.length) ? obj.length : _.keys(obj).length;
};
// Array Functions
// ---------------
@@ -319,11 +371,11 @@
// allows it to work with `_.map`.
_.first = _.head = _.take = function(array, n, guard) {
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`.
_.initial = function(array, n, guard) {
return slice.call(array, 0, array.length - ((n == null) || guard ? 1 : n));
@@ -337,64 +389,70 @@
} 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; });
};
+ // 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).
_.without = function(array) {
return _.difference(array, slice.call(arguments, 1));
};
// 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;
+ _.uniq = _.unique = function(array, isSorted, iterator, context) {
+ var initial = iterator ? _.map(array, iterator, context) : array;
var results = [];
- // The `isSorted` flag is irrelevant if the array only contains two elements.
- if (array.length < 3) isSorted = true;
- _.reduce(initial, function (memo, value, index) {
- if (isSorted ? _.last(memo) !== value || !memo.length : !_.include(memo, value)) {
- memo.push(value);
+ 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 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) {
return _.indexOf(other, item) >= 0;
});
@@ -402,48 +460,67 @@
};
// 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) {
- var rest = _.flatten(slice.call(arguments, 1), true);
- return _.filter(array, function(value){ return !_.include(rest, value); });
+ 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
// an index go together.
_.zip = function() {
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) {
+ 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.
// Delegates to **ECMAScript 5**'s native `indexOf` if available.
// If the array is large and already in sort order, pass `true`
// 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 (i in array && 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) {
- if (array == null) return -1;
- if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item);
- var i = array.length;
- while (i--) if (i in array && array[i] === item) return i;
+ _.lastIndexOf = function(array, item, fromIndex) {
+ if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item, fromIndex);
+ var i = (fromIndex != null ? fromIndex : array.length);
+ while (i--) if (array[i] === item) return i;
return -1;
};
// Generate an integer Array containing an arithmetic progression. A port of
// the native Python `range()` function. See
@@ -531,60 +608,67 @@
var whenDone = _.debounce(function(){ more = throttling = false; }, wait);
return function() {
context = this; args = arguments;
var later = function() {
timeout = null;
- if (more) func.apply(context, args);
+ if (more) {
+ result = func.apply(context, args);
+ }
whenDone();
};
if (!timeout) timeout = setTimeout(later, wait);
if (throttling) {
more = true;
} else {
+ throttling = true;
result = func.apply(context, args);
}
whenDone();
- throttling = true;
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. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
_.debounce = function(func, wait, immediate) {
- var timeout;
+ var timeout, result;
return function() {
var context = this, args = arguments;
var later = function() {
timeout = null;
- if (!immediate) func.apply(context, args);
+ if (!immediate) result = func.apply(context, args);
};
- if (immediate && !timeout) func.apply(context, args);
+ var callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
+ if (callNow) result = func.apply(context, args);
+ return result;
};
};
// Returns a function that will be executed at most one time, no matter how
// often you call it. Useful for lazy initialization.
_.once = function(func) {
var ran = false, memo;
return function() {
if (ran) return memo;
ran = true;
- return memo = func.apply(this, arguments);
+ memo = func.apply(this, arguments);
+ func = null;
+ return memo;
};
};
// Returns the first function passed as an argument to the second,
// allowing you to adjust arguments, run code before and after, and
// conditionally execute the original function.
_.wrap = function(func, wrapper) {
return function() {
- var args = [func].concat(slice.call(arguments, 0));
+ var args = [func];
+ push.apply(args, arguments);
return wrapper.apply(this, args);
};
};
// Returns a function that is the composition of a list of functions, each
@@ -602,11 +686,13 @@
// 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);
+ }
};
};
// Object Functions
// ----------------
@@ -620,13 +706,29 @@
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.
// Aliased as `methods`
_.functions = _.methods = function(obj) {
var names = [];
for (var key in obj) {
@@ -645,17 +747,28 @@
return obj;
};
// Return a copy of the object only containing the whitelisted properties.
_.pick = function(obj) {
- var result = {};
- each(_.flatten(slice.call(arguments, 1)), function(key) {
- if (key in obj) result[key] = obj[key];
+ var copy = {};
+ var keys = concat.apply(ArrayProto, slice.call(arguments, 1));
+ each(keys, function(key) {
+ if (key in obj) copy[key] = obj[key];
});
- return result;
+ 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];
@@ -676,23 +789,20 @@
_.tap = function(obj, interceptor) {
interceptor(obj);
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;
// 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 (a.isEqual && _.isFunction(a.isEqual)) return a.isEqual(b);
- if (b.isEqual && _.isFunction(b.isEqual)) return b.isEqual(a);
+ 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.
@@ -718,41 +828,46 @@
a.ignoreCase == b.ignoreCase;
}
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;
// 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--) {
- // Ensure commutative equality for sparse arrays.
- if (!(result = size in a == size in b && eq(a[size], b[size], stack))) break;
+ if (!(result = eq(a[size], b[size], aStack, bStack))) break;
}
}
} else {
- // Objects with different constructors are not equivalent.
- if ('constructor' in a != 'constructor' in b || a.constructor != b.constructor) return false;
+ // 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], stack))) break;
+ 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) {
@@ -760,17 +875,18 @@
}
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) {
@@ -780,11 +896,11 @@
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?
// Delegates to ECMA5's native Array.isArray
_.isArray = nativeIsArray || function(obj) {
@@ -794,72 +910,59 @@
// Is a given variable an object?
_.isObject = function(obj) {
return obj === Object(obj);
};
- // Is a given variable an arguments object?
- _.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 + ']';
+ };
+ });
+
+ // 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 && _.has(obj, 'callee'));
};
}
- // Is a given value a function?
- _.isFunction = function(obj) {
- return toString.call(obj) == '[object Function]';
- };
+ // Optimize `isFunction` if appropriate.
+ if (typeof (/./) !== 'function') {
+ _.isFunction = function(obj) {
+ return typeof obj === 'function';
+ };
+ }
- // Is a given value a string?
- _.isString = function(obj) {
- return toString.call(obj) == '[object String]';
- };
-
- // 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 _.isNumber(obj) && isFinite(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?
_.isBoolean = function(obj) {
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;
};
// Is a given variable undefined?
_.isUndefined = function(obj) {
return obj === void 0;
};
- // Has own property?
+ // 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
@@ -876,32 +979,69 @@
_.identity = function(value) {
return value;
};
// Run a function **n** times.
- _.times = function (n, iterator, context) {
+ _.times = function(n, iterator, context) {
for (var i = 0; i < n; i++) iterator.call(context, i);
};
- // Escape a string for HTML interpolation.
- _.escape = function(string) {
- return (''+string).replace(/&/g, '&').replace(/</g, '<').replace(/>/g, '>').replace(/"/g, '"').replace(/'/g, ''').replace(/\//g,'/');
+ // Return a random integer between min and max (inclusive).
+ _.random = function(min, max) {
+ if (max == null) {
+ max = min;
+ min = 0;
+ }
+ return min + (0 | Math.random() * (max - min + 1));
};
+ // List of HTML entities for escaping.
+ var entityMap = {
+ escape: {
+ '&': '&',
+ '<': '<',
+ '>': '>',
+ '"': '"',
+ "'": ''',
+ '/': '/'
+ }
+ };
+ entityMap.unescape = _.invert(entityMap.escape);
+
+ // 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')
+ };
+
+ // 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, ensuring that
- // they're correctly added to the OOP wrapper as well.
+ // 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));
+ };
});
};
// Generate a unique integer id (unique within the entire client session).
// Useful for temporary DOM ids.
@@ -920,140 +1060,127 @@
};
// 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 = /.^/;
+ 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'
+ "'": "'",
+ '\\': '\\',
+ '\r': 'r',
+ '\n': 'n',
+ '\t': 't',
+ '\u2028': 'u2028',
+ '\u2029': 'u2029'
};
- for (var p in escapes) escapes[escapes[p]] = p;
var escaper = /\\|'|\r|\n|\t|\u2028|\u2029/g;
- var unescaper = /\\(\\|'|r|n|t|u2028|u2029)/g;
- // Within an interpolation, evaluation, or escaping, remove HTML escaping
- // that had been previously added.
- var unescape = function(code) {
- return code.replace(unescaper, function(match, escape) {
- return escapes[escape];
- });
- };
-
// 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(text, data, settings) {
- settings = _.defaults(settings || {}, _.templateSettings);
+ settings = _.defaults({}, settings, _.templateSettings);
- // Compile the template source, taking care to escape characters that
- // cannot be included in a string literal and then unescape them in code
- // blocks.
- var source = "__p+='" + text
- .replace(escaper, function(match) {
- return '\\' + escapes[match];
- })
- .replace(settings.escape || noMatch, function(match, code) {
- return "'+\n_.escape(" + unescape(code) + ")+\n'";
- })
- .replace(settings.interpolate || noMatch, function(match, code) {
- return "'+\n(" + unescape(code) + ")+\n'";
- })
- .replace(settings.evaluate || noMatch, function(match, code) {
- return "';\n" + unescape(code) + "\n;__p+='";
- }) + "';\n";
+ // 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]; });
+ source +=
+ escape ? "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'" :
+ interpolate ? "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'" :
+ evaluate ? "';\n" + evaluate + "\n__p+='" : '';
+ index = offset + match.length;
+ });
+ 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 __p='';" +
- "var print=function(){__p+=Array.prototype.join.call(arguments, '')};\n" +
+ source = "var __t,__p='',__j=Array.prototype.join," +
+ "print=function(){__p+=__j.call(arguments,'');};\n" +
source + "return __p;\n";
- var render = new Function(settings.variable || 'obj', '_', source);
+ try {
+ var 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 build time
- // precompilation.
- template.source = 'function(' + (settings.variable || 'obj') + '){\n' +
- source + '}';
+ // 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();
};
- // The OOP Wrapper
+ // 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;
+ var result = function(obj) {
+ return this._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);
- };
- };
-
// Add all of the Underscore functions to the wrapper object.
_.mixin(_);
// 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() {
- var wrapped = this._wrapped;
- method.apply(wrapped, arguments);
- var length = wrapped.length;
- if ((name == 'shift' || name == 'splice') && length === 0) delete wrapped[0];
- return result(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);