Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

604 lines (442 sloc) 19.876 kb
# Underscore.coffee
# (c) 2010 Jeremy Ashkenas, DocumentCloud Inc.
# Underscore is freely distributable under the terms of the MIT license.
# Portions of Underscore are inspired by or borrowed from Prototype.js,
# Oliver Steele's Functional, and John Resig's Micro-Templating.
# For all details and documentation:
# http://documentcloud.github.com/underscore/
# ------------------------- Baseline setup ---------------------------------
# Establish the root object, "window" in the browser, or "global" on the server.
root: this
# Save the previous value of the "_" variable.
previousUnderscore: root._
# 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.
wrapper: (obj) ->
this._wrapped: obj
this
# Establish the object that gets thrown to break out of a loop iteration.
breaker: if typeof(StopIteration) is 'undefined' then '__break__' else StopIteration
# Create a safe reference to the Underscore object forreference below.
_: root._: (obj) -> new wrapper(obj)
# Export the Underscore object for CommonJS.
if typeof(exports) != 'undefined' then exports._: _
# Create quick reference variables for speed access to core prototypes.
slice: Array::slice
unshift: Array::unshift
toString: Object::toString
hasOwnProperty: Object::hasOwnProperty
propertyIsEnumerable: Object::propertyIsEnumerable
# Current version.
_.VERSION: '0.5.8'
# ------------------------ Collection Functions: ---------------------------
# The cornerstone, an each implementation.
# Handles objects implementing forEach, arrays, and raw objects.
_.each: (obj, iterator, context) ->
index: 0
try
return obj.forEach(iterator, context) if obj.forEach
if _.isNumber(obj.length)
return iterator.call(context, obj[i], i, obj) for i in [0...obj.length]
iterator.call(context, val, key, obj) for key, val of obj
catch e
throw e if e isnt breaker
obj
# Return the results of applying the iterator to each element. Use JavaScript
# 1.6's version of map, if possible.
_.map: (obj, iterator, context) ->
return obj.map(iterator, context) if (obj and _.isFunction(obj.map))
results: []
_.each obj, (value, index, list) ->
results.push(iterator.call(context, value, index, list))
results
# Reduce builds up a single result from a list of values. Also known as
# inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
_.reduce: (obj, memo, iterator, context) ->
return obj.reduce(_.bind(iterator, context), memo) if (obj and _.isFunction(obj.reduce))
_.each obj, (value, index, list) ->
memo: iterator.call(context, memo, value, index, list)
memo
# The right-associative version of reduce, also known as foldr. Uses
# JavaScript 1.8's version of reduceRight, if available.
_.reduceRight: (obj, memo, iterator, context) ->
return obj.reduceRight(_.bind(iterator, context), memo) if (obj and _.isFunction(obj.reduceRight))
_.each _.clone(_.toArray(obj)).reverse(), (value, index) ->
memo: iterator.call(context, memo, value, index, obj)
memo
# Return the first value which passes a truth test.
_.detect: (obj, iterator, context) ->
result: null
_.each obj, (value, index, list) ->
if iterator.call(context, value, index, list)
result: value
_.breakLoop()
result
# Return all the elements that pass a truth test. Use JavaScript 1.6's
# filter(), if it exists.
_.select: (obj, iterator, context) ->
if obj and _.isFunction(obj.filter) then return obj.filter(iterator, context)
results: []
_.each obj, (value, index, list) ->
results.push(value) if iterator.call(context, value, index, list)
results
# Return all the elements for which a truth test fails.
_.reject: (obj, iterator, context) ->
results: []
_.each obj, (value, index, list) ->
results.push(value) if not iterator.call(context, value, index, list)
results
# Determine whether all of the elements match a truth test. Delegate to
# JavaScript 1.6's every(), if it is present.
_.all: (obj, iterator, context) ->
iterator ||= _.identity
return obj.every(iterator, context) if obj and _.isFunction(obj.every)
result: true
_.each obj, (value, index, list) ->
_.breakLoop() unless (result: result and iterator.call(context, value, index, list))
result
# Determine if at least one element in the object matches a truth test. Use
# JavaScript 1.6's some(), if it exists.
_.any: (obj, iterator, context) ->
iterator ||= _.identity
return obj.some(iterator, context) if obj and _.isFunction(obj.some)
result: false
_.each obj, (value, index, list) ->
_.breakLoop() if (result: iterator.call(context, value, index, list))
result
# Determine if a given value is included in the array or object,
# based on '==='.
_.include: (obj, target) ->
return _.indexOf(obj, target) isnt -1 if obj and _.isFunction(obj.indexOf)
for key, val of obj
return true if val is target
false
# Invoke a method with arguments on every item in a collection.
_.invoke: (obj, method) ->
args: _.rest(arguments, 2)
(if method then val[method] else val).apply(val, args) for val in obj
# Convenience version of a common use case of map: fetching a property.
_.pluck: (obj, key) ->
_.map(obj, ((val) -> val[key]))
# Return the maximum item or (item-based computation).
_.max: (obj, iterator, context) ->
return Math.max.apply(Math, obj) if not iterator and _.isArray(obj)
result: {computed: -Infinity}
_.each obj, (value, index, list) ->
computed: if iterator then iterator.call(context, value, index, list) else value
computed >= result.computed and (result: {value: value, computed: computed})
result.value
# Return the minimum element (or element-based computation).
_.min: (obj, iterator, context) ->
return Math.min.apply(Math, obj) if not iterator and _.isArray(obj)
result: {computed: Infinity}
_.each obj, (value, index, list) ->
computed: if iterator then iterator.call(context, value, index, list) else value
computed < result.computed and (result: {value: value, computed: computed})
result.value
# Sort the object's values by a criteria produced by an iterator.
_.sortBy: (obj, iterator, context) ->
_.pluck(((_.map obj, (value, index, list) ->
{value: value, criteria: iterator.call(context, value, index, list)}
).sort((left, right) ->
a: left.criteria; b: right.criteria
if a < b then -1 else if a > b then 1 else 0
)), 'value')
# Use a comparator function to figure out at what index an object should
# be inserted so as to maintain order. Uses binary search.
_.sortedIndex: (array, obj, iterator) ->
iterator ||= _.identity
low: 0; high: array.length
while low < high
mid: (low + high) >> 1
if iterator(array[mid]) < iterator(obj) then low: mid + 1 else high: mid
low
# Convert anything iterable into a real, live array.
_.toArray: (iterable) ->
return [] if (!iterable)
return iterable.toArray() if (iterable.toArray)
return iterable if (_.isArray(iterable))
return slice.call(iterable) if (_.isArguments(iterable))
_.values(iterable)
# Return the number of elements in an object.
_.size: (obj) -> _.toArray(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: (array, n, guard) ->
if n and not guard then slice.call(array, 0, n) else array[0]
# 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"
# check allows it to work with _.map.
_.rest: (array, index, guard) ->
slice.call(array, if _.isUndefined(index) or guard then 1 else index)
# Get the last element of an array.
_.last: (array) -> array[array.length - 1]
# Trim out all falsy values from an array.
_.compact: (array) -> item for item in array when item
# Return a completely flattened version of an array.
_.flatten: (array) ->
_.reduce array, [], (memo, value) ->
return memo.concat(_.flatten(value)) if _.isArray(value)
memo.push(value)
memo
# Return a version of the array that does not contain the specified value(s).
_.without: (array) ->
values: _.rest(arguments)
val for val in _.toArray(array) when not _.include(values, val)
# Produce a duplicate-free version of the array. If the array has already
# been sorted, you have the option of using a faster algorithm.
_.uniq: (array, isSorted) ->
memo: []
for el, i in _.toArray(array)
memo.push(el) if i is 0 || (if isSorted is true then _.last(memo) isnt el else not _.include(memo, el))
memo
# Produce an array that contains every item shared between all the
# passed-in arrays.
_.intersect: (array) ->
rest: _.rest(arguments)
_.select _.uniq(array), (item) ->
_.all rest, (other) ->
_.indexOf(other, item) >= 0
# Zip together multiple lists into a single array -- elements that share
# an index go together.
_.zip: ->
length: _.max(_.pluck(arguments, 'length'))
results: new Array(length)
for i in [0...length]
results[i]: _.pluck(arguments, String(i))
results
# 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 occurence of an
# item in an array, or -1 if the item is not included in the array.
_.indexOf: (array, item) ->
return array.indexOf(item) if array.indexOf
i: 0; l: array.length
while l - i
if array[i] is item then return i else i++
-1
# Provide JavaScript 1.6's lastIndexOf, delegating to the native function,
# if possible.
_.lastIndexOf: (array, item) ->
return array.lastIndexOf(item) if array.lastIndexOf
i: array.length
while i
if array[i] is item then return i else i--
-1
# Generate an integer Array containing an arithmetic progression. A port of
# the native Python range() function. See:
# http://docs.python.org/library/functions.html#range
_.range: (start, stop, step) ->
a: arguments
solo: a.length <= 1
i: start: if solo then 0 else a[0]
stop: if solo then a[0] else a[1]
step: a[2] or 1
len: Math.ceil((stop - start) / step)
return [] if len <= 0
range: new Array(len)
idx: 0
while true
return range if (if step > 0 then i - stop else stop - i) >= 0
range[idx]: i
idx++
i+= step
# ----------------------- Function Functions: -----------------------------
# Create a function bound to a given object (assigning 'this', and arguments,
# optionally). Binding with arguments is also known as 'curry'.
_.bind: (func, obj) ->
args: _.rest(arguments, 2)
-> func.apply(obj or root, args.concat(arguments))
# Bind all of an object's methods to that object. Useful for ensuring that
# all callbacks defined on an object belong to it.
_.bindAll: (obj) ->
funcs: if arguments.length > 1 then _.rest(arguments) else _.functions(obj)
_.each(funcs, (f) -> obj[f]: _.bind(obj[f], obj))
obj
# Delays a function for the given number of milliseconds, and then calls
# it with the arguments supplied.
_.delay: (func, wait) ->
args: _.rest(arguments, 2)
setTimeout((-> func.apply(func, args)), wait)
# Defers a function, scheduling it to run after the current call stack has
# cleared.
_.defer: (func) ->
_.delay.apply(_, [func, 1].concat(_.rest(arguments)))
# 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: (func, wrapper) ->
-> wrapper.apply(wrapper, [func].concat(arguments))
# Returns a function that is the composition of a list of functions, each
# consuming the return value of the function that follows.
_.compose: ->
funcs: arguments
->
args: arguments
for i in [(funcs.length - 1)..0]
args: [funcs[i].apply(this, args)]
args[0]
# ------------------------- Object Functions: ----------------------------
# Retrieve the names of an object's properties.
_.keys: (obj) ->
return _.range(0, obj.length) if _.isArray(obj)
key for key, val of obj
# Retrieve the values of an object's properties.
_.values: (obj) ->
_.map(obj, _.identity)
# Return a sorted list of the function names available in Underscore.
_.functions: (obj) ->
_.select(_.keys(obj), (key) -> _.isFunction(obj[key])).sort()
# Extend a given object with all of the properties in a source object.
_.extend: (destination, source) ->
for key, val of source
destination[key]: val
destination
# Create a (shallow-cloned) duplicate of an object.
_.clone: (obj) ->
return obj.slice(0) if _.isArray(obj)
_.extend({}, obj)
# Invokes interceptor with the obj, and then returns obj.
# The primary purpose of this method is to "tap into" a method chain, in order to perform operations on intermediate results within the chain.
_.tap: (obj, interceptor) ->
interceptor(obj)
obj
# Perform a deep comparison to check if two objects are equal.
_.isEqual: (a, b) ->
# Check object identity.
return true if a is b
# Different types?
atype: typeof(a); btype: typeof(b)
return false if atype isnt btype
# Basic equality test (watch out for coercions).
return true if `a == b`
# One is falsy and the other truthy.
return false if (!a and b) or (a and !b)
# One of them implements an isEqual()?
return a.isEqual(b) if a.isEqual
# Check dates' integer values.
return a.getTime() is b.getTime() if _.isDate(a) and _.isDate(b)
# Both are NaN?
return true if _.isNaN(a) and _.isNaN(b)
# Compare regular expressions.
if _.isRegExp(a) and _.isRegExp(b)
return a.source is b.source and
a.global is b.global and
a.ignoreCase is b.ignoreCase and
a.multiline is b.multiline
# If a is not an object by this point, we can't handle it.
return false if atype isnt 'object'
# Check for different array lengths before comparing contents.
return false if a.length and (a.length isnt b.length)
# Nothing else worked, deep compare the contents.
aKeys: _.keys(a); bKeys: _.keys(b)
# Different object sizes?
return false if aKeys.length isnt bKeys.length
# Recursive comparison of contents.
# for (var key in a) if (!_.isEqual(a[key], b[key])) return false;
return true
# Is a given array or object empty?
_.isEmpty: (obj) -> _.keys(obj).length is 0
# Is a given value a DOM element?
_.isElement: (obj) -> obj and obj.nodeType is 1
# Is a given value an array?
_.isArray: (obj) -> !!(obj and obj.concat and obj.unshift)
# Is a given variable an arguments object?
_.isArguments: (obj) -> obj and _.isNumber(obj.length) and not obj.concat and
not obj.substr and not obj.apply and not propertyIsEnumerable.call(obj, 'length')
# Is the given value a function?
_.isFunction: (obj) -> !!(obj and obj.constructor and obj.call and obj.apply)
# Is the given value a string?
_.isString: (obj) -> !!(obj is '' or (obj and obj.charCodeAt and obj.substr))
# Is a given value a number?
_.isNumber: (obj) -> (obj is +obj) or toString.call(obj) is '[object Number]'
# Is a given value a Date?
_.isDate: (obj) -> !!(obj and obj.getTimezoneOffset and obj.setUTCFullYear)
# Is the given value a regular expression?
_.isRegExp: (obj) -> !!(obj and obj.exec and (obj.ignoreCase or obj.ignoreCase is false))
# Is the given value NaN -- this one is interesting. NaN != NaN, and
# isNaN(undefined) == true, so we make sure it's a number first.
_.isNaN: (obj) -> _.isNumber(obj) and window.isNaN(obj)
# Is a given value equal to null?
_.isNull: (obj) -> obj is null
# Is a given variable undefined?
_.isUndefined: (obj) -> typeof obj is 'undefined'
# -------------------------- Utility Functions: --------------------------
# Run Underscore.js in noConflict mode, returning the '_' variable to its
# previous owner. Returns a reference to the Underscore object.
_.noConflict: ->
root._: previousUnderscore
this
# Keep the identity function around for default iterators.
_.identity: (value) -> value
# Break out of the middle of an iteration.
_.breakLoop: -> throw breaker
# Generate a unique integer id (unique within the entire client session).
# Useful for temporary DOM ids.
idCounter: 0
_.uniqueId: (prefix) ->
(prefix or '') + idCounter++
# By default, Underscore uses ERB-style template delimiters, change the
# following template settings to use alternative delimiters.
_.templateSettings: {
start: '<%'
end: '%>'
interpolate: /<%=(.+?)%>/g
}
# JavaScript templating a-la ERB, pilfered from John Resig's
# "Secrets of the JavaScript Ninja", page 83.
# Single-quote fix from Rick Strahl's version.
_.template: (str, data) ->
c: _.templateSettings
fn: new Function 'obj',
'var p=[],print=function(){p.push.apply(p,arguments);};' +
'with(obj){p.push(\'' +
str.replace(/[\r\t\n]/g, " ")
.replace(new RegExp("'(?=[^"+c.end[0]+"]*"+c.end+")","g"),"\t")
.split("'").join("\\'")
.split("\t").join("'")
.replace(c.interpolate, "',$1,'")
.split(c.start).join("');")
.split(c.end).join("p.push('") +
"');}return p.join('');"
if data then fn(data) else fn
# ------------------------------- Aliases ----------------------------------
_.forEach: _.each
_.foldl: _.inject: _.reduce
_.foldr: _.reduceRight
_.filter: _.select
_.every: _.all
_.some: _.any
_.head: _.first
_.tail: _.rest
_.methods: _.functions
# ------------------------ Setup the OOP Wrapper: --------------------------
# Helper function to continue chaining intermediate results.
result: (obj, chain) ->
if chain then _(obj).chain() else obj
# Add all of the Underscore functions to the wrapper object.
_.each _.functions(_), (name) ->
method: _[name]
wrapper.prototype[name]: ->
unshift.call(arguments, this._wrapped)
result(method.apply(_, arguments), this._chain)
# Add all mutator Array functions to the wrapper.
_.each ['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], (name) ->
method: Array.prototype[name]
wrapper.prototype[name]: ->
method.apply(this._wrapped, arguments)
result(this._wrapped, this._chain)
# Add all accessor Array functions to the wrapper.
_.each ['concat', 'join', 'slice'], (name) ->
method: Array.prototype[name]
wrapper.prototype[name]: ->
result(method.apply(this._wrapped, arguments), this._chain)
# Start chaining a wrapped Underscore object.
wrapper::chain: ->
this._chain: true
this
# Extracts the result from a wrapped and chained object.
wrapper::value: -> this._wrapped
Jump to Line
Something went wrong with that request. Please try again.