git ssb

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var LazyWatcher = require('./lib/lazy-watcher')
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var resolve = require('./resolve')
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var isObservable = require('./is-observable')
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module.exports = ProxyCollection
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function ProxyCollection (source) {
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  var releases = []
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  var binder = LazyWatcher(update, listen, unlisten)
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  binder.value = resolve(source)
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  var observable = function MutantProxyCollection (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.get = function (index) {
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    if (isObservable(source) && source.get) {
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      return source.get(index)
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    } else if (Array.isArray(resolve(source))) {
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      return resolve(source)[index]
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    }
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  }
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  observable.getLength = function () {
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    if (isObservable(source) && source.getLength) {
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      return source.getLength()
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    } else if (Array.isArray(resolve(source))) {
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      return resolve(source).length
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    }
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  }
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  observable.includes = function (value) {
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    if (isObservable(source) && source.includes) {
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      return source.includes(value)
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    } else if (Array.isArray(resolve(source))) {
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      return !!~resolve(source).indexOf(value)
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    }
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  }
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  observable.indexOf = function (value) {
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    if (isObservable(source) && source.indexOf) {
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      return source.indexOf(value)
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    } else if (Array.isArray(resolve(source))) {
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      return resolve(source).indexOf(value)
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    }
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  }
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  observable.forEach = function (fn, context) {
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    if (isObservable(source) && source.forEach) {
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      return source.forEach(fn, context)
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    } else if (Array.isArray(resolve(source))) {
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      return resolve(source).slice().forEach(fn, context)
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    }
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  }
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  observable.find = function (fn) {
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    if (isObservable(source) && source.find) {
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      return source.find(fn)
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    } else if (Array.isArray(resolve(source))) {
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      return resolve(source).find(fn)
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    }
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  }
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  observable.set = function (newSource) {
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    unlisten()
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    source = newSource
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    if (binder.live) {
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      listen()
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    }
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    binder.onUpdate()
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  }
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  return observable
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  // scoped
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  function listen () {
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    if (isObservable(source)) {
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      releases.push(
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        source(binder.onUpdate)
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      )
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    }
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  }
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  function unlisten () {
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    while (releases.length) {
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      releases.pop()()
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    }
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  }
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  function update () {
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    binder.value = resolve(source) || {}
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    return true
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  }
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}
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