iter.js
Python style iteration utilities.

File Location

iter/iter.js

Classes

goog.iter.Iterator
Class/interface for iterators. An iterator needs to implement a next method and it needs to throw a goog.iter.StopIteration when the iteration passes beyond the end. Iterators have no hasNext method. It is recommended to always use the helper functions to iterate over the iterator or in case you are only targeting JavaScript 1.7 for in loops.

Public Protected Private

Global Functions

goog.iter.chain(var_args) ⇒
goog.iter.Iterator
Takes zero or more iterators and returns one iterator that will iterate over them in the order chained.
Arguments:
var_args :
(goog.iter.Iterator | null | undefined)
Any number of iterator objects.
Returns: 
goog.iter.Iterator
  Returns a new iterator that will iterate over all the given iterators' contents.
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goog.iter.cycle(iterable) ⇒
goog.iter.Iterator
Create an iterator to cycle over the iterable's elements indefinitely. For example, ([1, 2, 3]) would return : 1, 2, 3, 1, 2, 3, ...
Arguments:
iterable :
(goog.iter.Iterator | {__iterator__: ?} | {length: number})
The iterable object.
Returns: 
goog.iter.Iterator
  An iterator that iterates indefinitely over the values in iterable.
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goog.iter.dropWhile(iterable, f, opt_obj) ⇒
goog.iter.Iterator
Builds a new iterator that iterates over the original, but skips elements as long as a supplied function returns true.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator object.
f :
(Function | null)
The function to call for every value. This function takes 3 arguments (the value, undefined, and the iterator) and should return a boolean.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
goog.iter.Iterator
  A new iterator that drops elements from the original iterator as long as f is true.
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goog.iter.equals(iterable1, iterable2) ⇒
boolean
Iterates over 2 iterators and returns true if they contain the same sequence of elements and have the same length.
Arguments:
iterable1 :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The first iterable object.
iterable2 :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The second iterable object.
Returns: 
boolean
  true if the iterators contain the same sequence of elements and have the same length.
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goog.iter.every(iterable, f, opt_obj) ⇒
boolean
Goes through the values in the iterator. Calls f for each these and if any of them returns false this returns false (without checking the rest). If all return true this will return true.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator object.
f :
(Function | null)
The function to call for every value. This function takes 3 arguments (the value, undefined, and the iterator) and should return a boolean.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
boolean
  true if every value passes the test.
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goog.iter.filter(iterable, f, opt_obj) ⇒
goog.iter.Iterator
Calls a function for every element in the iterator, and if the function returns true adds the element to a new iterator.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to iterate over.
f :
(Function | null)
The function to call for every element. This function takes 3 arguments (the element, undefined, and the iterator) and should return a boolean. If the return value is true the element will be included in the returned iteror. If it is false the element is not included.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
goog.iter.Iterator
  A new iterator in which only elements that passed the test are present.
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goog.iter.forEach(iterable, f, opt_obj)
Calls a function for each element in the iterator with the element of the iterator passed as argument.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to iterate over. If the iterable is an object toIterator will be called on it.
f :
(Function | null)
The function to call for every element. This function takes 3 arguments (the element, undefined, and the iterator) and the return value is irrelevant. The reason for passing undefined as the second argument is so that the same function can be used in goog.array#forEach as well as others.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
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goog.iter.join(iterable, deliminator) ⇒
string
Joins the values in a iterator with a delimiter.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to get the values from.
deliminator :
string
The text to put between the values.
Returns: 
string
  The joined value string.
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goog.iter.map(iterable, f, opt_obj) ⇒
goog.iter.Iterator
For every element in the iterator call a function and return a new iterator with that value.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to iterate over.
f :
(Function | null)
The function to call for every element. This function takes 3 arguments (the element, undefined, and the iterator) and should return a new value.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
goog.iter.Iterator
  A new iterator that returns the results of applying the function to each element in the original iterator.
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goog.iter.nextOrValue(iterable, defaultValue) ⇒
*
Advances the iterator to the next position, returning the given default value instead of throwing an exception if the iterator has no more entries.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterable object.
defaultValue :
*
The value to return if the iterator is empty.
Returns: 
*
  The next item in the iteration, or defaultValue if the iterator was empty.
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goog.iter.product(var_args) ⇒
goog.iter.Iterator
Cartesian product of zero or more sets. Gives an iterator that gives every combination of one element chosen from each set. For example, ([1, 2], [3, 4]) gives ([1, 3], [1, 4], [2, 3], [2, 4]).
Arguments:
var_args :
(undefined | {length: number})
Zero or more sets, as arrays.
Returns: 
goog.iter.Iterator
  An iterator that gives each n-tuple (as an array).
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goog.iter.range(startOrStop, opt_stop, opt_step) ⇒
goog.iter.Iterator
Creates a new iterator that returns the values in a range. This function can take 1, 2 or 3 arguments: 
range(5) same as range(0, 5, 1)
range(2, 5) same as range(2, 5, 1)
Arguments:
startOrStop :
number
The stop value if only one argument is provided. The start value if 2 or more arguments are provided. If only one argument is used the start value is 0.
opt_stop :
(number | undefined)
The stop value. If left out then the first argument is used as the stop value.
opt_step :
(number | undefined)
The number to increment with between each call to next. This can be negative.
Returns: 
goog.iter.Iterator
  A new iterator that returns the values in the range.
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goog.iter.reduce(iterable, f, val, opt_obj) ⇒
*
Passes every element of an iterator into a function and accumulates the result.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to iterate over.
f :
(Function | null)
The function to call for every element. This function takes 2 arguments (the function's previous result or the initial value, and the value of the current element). function(previousValue, currentElement) : newValue.
val :
*
The initial value to pass into the function on the first call.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
*
  Result of evaluating f repeatedly across the values of the iterator.
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goog.iter.some(iterable, f, opt_obj) ⇒
boolean
Goes through the values in the iterator. Calls f for each these and if any of them returns true, this returns true (without checking the rest). If all return false this will return false.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator object.
f :
(Function | null)
The function to call for every value. This function takes 3 arguments (the value, undefined, and the iterator) and should return a boolean.
opt_obj :
(Object | null | undefined)
The object to be used as the value of 'this' within f.
Returns: 
boolean
  true if any value passes the test.
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goog.iter.takeWhile(iterable, f, opt_obj) ⇒
goog.iter.Iterator
Builds a new iterator that iterates over the original, but only as long as a supplied function returns true.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator object.
f :
(Function | null)
The function to call for every value. This function takes 3 arguments (the value, undefined, and the iterator) and should return a boolean.
opt_obj :
(Object | null | undefined)
This is used as the 'this' object in f when called.
Returns: 
goog.iter.Iterator
  A new iterator that keeps elements in the original iterator as long as the function is true.
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goog.iter.toArray(iterable) ⇒
Array
Converts the iterator to an array
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
The iterator to convert to an array.
Returns: 
Array
  An array of the elements the iterator iterates over.
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goog.iter.toIterator(iterable) ⇒
goog.iter.Iterator
Returns an iterator that knows how to iterate over the values in the object.
Arguments:
iterable :
(goog.iter.Iterator | null | {__iterator__: ?} | {length: number})
If the object is an iterator it will be returned as is. If the object has a __iterator__ method that will be called to get the value iterator. If the object is an array-like object we create an iterator for that.
Returns: 
goog.iter.Iterator
  An iterator that knows how to iterate over the values in iterable.
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Global Properties

goog.iter.StopIteration :
(Error | null)
Singleton Error object that is used to terminate iterations.
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Directory iter

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