PriorityQueue.coffee

sortedIndex = require('lodash/sortedIndex')

module.exports = class PriorityQueue

    constructor: () ->
        @heap = []
        @length = 0
        
    push: (item, priority=0) ->
        data =
            data: item,
            priority: priority
    
        index = sortedIndex @heap, data, "priority"
      
        @heap.splice index, 0, data
        return @length = @heap.length
    
    pop: () ->
        item = @heap.pop()
        @length = @heap.length
        if item then item.data else undefined