git ssb

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var LazyWatcher = require('./lib/lazy-watcher')
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var isReferenceType = require('./lib/is-reference-type')
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var resolve = require('./resolve')
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module.exports = Array
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function Array (defaultValues) {
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  var object = []
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  var sources = []
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  var releases = []
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  var binder = LazyWatcher(update, listen, unlisten)
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  binder.value = object
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  if (defaultValues && defaultValues.length) {
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    defaultValues.forEach(add)
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  }
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  var observable = function MutantArray (listener) {
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    if (!listener) {
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      return binder.getValue()
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    }
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    return binder.addListener(listener)
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  }
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  observable.push = function (args) {
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    for (var i = 0; i < arguments.length; i++) {
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      add(arguments[i])
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    }
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    binder.broadcast()
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  }
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  observable.insert = function (valueOrObs, at) {
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    sources.splice(at, 0, valueOrObs)
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    if (binder.live) releases.splice(at, 0, bind(valueOrObs))
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    object.splice(at, 0, resolve(valueOrObs))
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    binder.broadcast()
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  }
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  observable.get = function (index) {
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    return sources[index]
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  }
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  observable.getLength = function (index) {
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    return sources.length
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  }
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  observable.includes = function (valueOrObs) {
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    return !!~sources.indexOf(valueOrObs)
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  }
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  observable.indexOf = function (valueOrObs) {
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    return sources.indexOf(valueOrObs)
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  }
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  observable.forEach = function (fn, context) {
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    sources.slice().forEach(fn, context)
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  }
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  observable.find = function (fn) {
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    return sources.find(fn)
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  }
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  observable.indexOf
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  observable.pop = function () {
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    var result = sources.pop()
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    if (binder.live) tryInvoke(releases.pop())
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    object.pop()
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    binder.broadcast()
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    return result
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  }
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  observable.shift = function () {
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    var result = sources.shift()
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    if (binder.live) tryInvoke(releases.shift())
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    object.shift()
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    binder.broadcast()
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    return result
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  }
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  observable.clear = function () {
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    releases.forEach(tryInvoke)
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    sources.length = 0
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    releases.length = 0
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    object.length = 0
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    binder.broadcast()
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  }
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  observable.delete = function (valueOrObs) {
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    var index = sources.indexOf(valueOrObs)
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    if (~index) {
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      sources.splice(index, 1)
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      if (binder.live) releases.splice(index, 1).forEach(tryInvoke)
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      object.splice(index, 1)
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      binder.broadcast()
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    }
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  }
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  observable.set = function (values) {
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    unlisten()
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    sources.length = 0
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    releases.length = 0
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    object.length = 0
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    values.forEach(add)
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    if (binder.live) {
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      listen()
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      binder.broadcast()
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    }
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  }
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  return observable
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  // scoped
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  function add (valueOrObs) {
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    sources.push(valueOrObs)
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    if (binder.live) {
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      releases.push(bind(valueOrObs))
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    }
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    object.push(resolve(valueOrObs))
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  }
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  function bind (valueOrObs) {
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    return typeof valueOrObs === 'function' ? valueOrObs(binder.onUpdate) : null
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  }
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  function listen () {
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    sources.forEach(function (obs, i) {
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      releases[i] = bind(obs)
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    })
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  }
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  function unlisten () {
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    releases.forEach(tryInvoke)
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    releases.length = 0
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  }
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  function update () {
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    var changed = false
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    sources.forEach(function (key, i) {
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      var newValue = resolve(observable[key])
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      if (newValue !== object[i] || isReferenceType(newValue)) {
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        object[i] = newValue
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        changed = true
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      }
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    })
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    return changed
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  }
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}
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function tryInvoke (func) {
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  if (typeof func === 'function') {
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    func()
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  }
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}
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