https://github.com/oddbird/greenmud
into the green green mud
https://github.com/oddbird/greenmud
Last synced: 3 months ago
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into the green green mud
- Host: GitHub
- URL: https://github.com/oddbird/greenmud
- Owner: oddbird
- Created: 2011-09-01T00:07:27.000Z (almost 14 years ago)
- Default Branch: master
- Last Pushed: 2021-03-29T17:37:23.000Z (over 4 years ago)
- Last Synced: 2024-10-29T18:48:50.145Z (8 months ago)
- Language: JavaScript
- Homepage: http://greengreenmud.com/
- Size: 20.4 MB
- Stars: 6
- Watchers: 4
- Forks: 0
- Open Issues: 3
-
Metadata Files:
- Readme: README.markdown
Awesome Lists containing this project
README
traverse
========
Traverse and transform objects by visiting every node on a recursive walk.
examples
========
transform negative numbers in-place
-----------------------------------
negative.js
````javascript
var traverse = require('traverse');
var obj = [ 5, 6, -3, [ 7, 8, -2, 1 ], { f : 10, g : -13 } ];
traverse(obj).forEach(function (x) {
if (x < 0) this.update(x + 128);
});
console.dir(obj);
````
Output:
[ 5, 6, 125, [ 7, 8, 126, 1 ], { f: 10, g: 115 } ]
collect leaf nodes
------------------
leaves.js
````javascript
var traverse = require('traverse');
var obj = {
a : [1,2,3],
b : 4,
c : [5,6],
d : { e : [7,8], f : 9 },
};
var leaves = traverse(obj).reduce(function (acc, x) {
if (this.isLeaf) acc.push(x);
return acc;
}, []);
console.dir(leaves);
````
Output:
[ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
scrub circular references
-------------------------
scrub.js:
````javascript
var traverse = require('traverse');
var obj = { a : 1, b : 2, c : [ 3, 4 ] };
obj.c.push(obj);
var scrubbed = traverse(obj).map(function (x) {
if (this.circular) this.remove()
});
console.dir(scrubbed);
````
output:
{ a: 1, b: 2, c: [ 3, 4 ] }
context
=======
Each method that takes a callback has a context (its `this` object) with these
attributes:
this.node
---------
The present node on the recursive walk
this.path
---------
An array of string keys from the root to the present node
this.parent
-----------
The context of the node's parent.
This is `undefined` for the root node.
this.key
--------
The name of the key of the present node in its parent.
This is `undefined` for the root node.
this.isRoot, this.notRoot
-------------------------
Whether the present node is the root node
this.isLeaf, this.notLeaf
-------------------------
Whether or not the present node is a leaf node (has no children)
this.level
----------
Depth of the node within the traversal
this.circular
-------------
If the node equals one of its parents, the `circular` attribute is set to the
context of that parent and the traversal progresses no deeper.
this.update(value, stopHere=false)
----------------------------------
Set a new value for the present node.
All the elements in `value` will be recursively traversed unless `stopHere` is
true.
this.remove(stopHere=false)
-------------
Remove the current element from the output. If the node is in an Array it will
be spliced off. Otherwise it will be deleted from its parent.
this.delete(stopHere=false)
-------------
Delete the current element from its parent in the output. Calls `delete` even on
Arrays.
this.before(fn)
---------------
Call this function before any of the children are traversed.
You can assign into `this.keys` here to traverse in a custom order.
this.after(fn)
--------------
Call this function after any of the children are traversed.
this.pre(fn)
------------
Call this function before each of the children are traversed.
this.post(fn)
-------------
Call this function after each of the children are traversed.
methods
=======
.map(fn)
--------
Execute `fn` for each node in the object and return a new object with the
results of the walk. To update nodes in the result use `this.update(value)`.
.forEach(fn)
------------
Execute `fn` for each node in the object but unlike `.map()`, when
`this.update()` is called it updates the object in-place.
.reduce(fn, acc)
----------------
For each node in the object, perform a
[left-fold](http://en.wikipedia.org/wiki/Fold_(higher-order_function))
with the return value of `fn(acc, node)`.
If `acc` isn't specified, `acc` is set to the root object for the first step
and the root element is skipped.
.paths()
--------
Return an `Array` of every possible non-cyclic path in the object.
Paths are `Array`s of string keys.
.nodes()
--------
Return an `Array` of every node in the object.
.clone()
--------
Create a deep clone of the object.
install
=======
Using [npm](http://npmjs.org) do:
$ npm install traverse
test
====
Using [expresso](http://github.com/visionmedia/expresso) do:
$ expresso
100% wahoo, your stuff is not broken!
in the browser
==============
Use [browserify](https://github.com/substack/node-browserify) to run traverse in
the browser.
traverse has been tested and works with:
* Internet Explorer 5.5, 6.0, 7.0, 8.0, 9.0
* Firefox 3.5
* Chrome 6.0
* Opera 10.6
* Safari 5.0