Supersede NPM | npm.io

A path based set where the most specific path wins.

Synopsis

var assert = require('assert')
var supersede = require('supersede')

// create a set
var set = new Supersede

// set a value keyed to a path of depth 2.
set.set('.hello.world'.split('.'), 'hello, world')

// get the value
assert.equal(set.get('.hello.world'), 'hello, world')

// get a non-existant value
assert.equal(set.get('.hello.earth'), null)

// set a value keyed to a path of depth 1.
assert.equal(set.get('.hello'), 'hello, you')

// parent value is used
assert.equal(set.get('.hello.earth'), 'hello, earth')

// the most specific path wins
assert.equal(set.get('.hello.world'), 'hello, world')

// gather along a path
assert.deepEqual(set.gather('.hello.world'), [ 'hello, earth', 'hello, world' ])

Usage

Keys are generated by calling split('.') on a path string that begins with a dot '.' where path steps are dot '.' delimited.

var assert = require('assert')

var rootPath = '.'.split('.')
var otherPath = '.hello.world'.split('.')

assert.deepEqual(rootPath, [ '', '' ])
assert.deepEqual(otherPath, [ '', 'hello', 'world' ])

Supersede does not perform this split itself because if you're really in a hurry you might want to save the generated arrays for later use, or type out the key as an array literal.

`supersede = new Supersede`

Create an empty set.

`supersede.set(path, value)`

Sets a key to the given value overriding any key.

`supersede.gather(path, value)`

Gathers the values along the given path into an array. If there are no values along the path an empty array is returned.

`supersede.remove(path)`

Removes the value of the node specified by the given path.

Diary

The star '*' here is special and needs to be used carefully. Using it to remove all might not be the best.

What if we want to register a listener, so we place a '*' in the tree itself? Then we can search a path where we look for everything that is the given step or a star, but now we are getting into some recursive pattern matching. Do we really want to match '*' star?

signal.on('system.web.rost', handler1)
signal.on('system.*.error', handler2)

signal.on('system.web.logger.info', logger.info)

What is going to be useful? So much thought to put into late binding.

The only place that is useful is in gather, so I can make a new function that respsects that, but it would be slightly more expensive than gather, but only slightly more. It will not be universal. It can only be for '*'.