Class: Sack

Inherits:
Haversack::ItemCollection show all
Defined in:
lib/haversack/sack.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Haversack::ItemCollection

only_items?, #size, #weight

Constructor Details

#initialize(data, capacity:, max_weight:, &block) ⇒ Sack

Returns a new instance of Sack.

Raises:



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# File 'lib/haversack/sack.rb', line 8

def initialize(data, capacity:, max_weight:, &block)

@capacity   = capacity
@max_weight = max_weight

block_given? ? super(data, &block) : super(data)

raise Haversack::KnapsackCapacityExceededError if contents_exceed_capacity?
raise Haversack::KnapsackWeightExceededError   if contents_exceed_weight?
end

Instance Attribute Details

#capacity ⇒ Object

Returns the value of attribute capacity.



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# File 'lib/haversack/sack.rb', line 5

def capacity
  @capacity
end

#max_weight ⇒ Object

Returns the value of attribute max_weight.



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# File 'lib/haversack/sack.rb', line 6

def max_weight
  @max_weight
end

Instance Method Details

#available_capacity ⇒ Object 



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# File 'lib/haversack/sack.rb', line 23

def available_capacity
  empty? ? @capacity : (@capacity - size)
end

#available_weight ⇒ Object 



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# File 'lib/haversack/sack.rb', line 19

def available_weight
  empty? ? @max_weight : (@max_weight - weight)
end

#exceeds_capacity?(item) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/haversack/sack.rb', line 39

def exceeds_capacity?(item)
  !fits_capacity?(item)
end

#exceeds_weight?(item) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/haversack/sack.rb', line 31

def exceeds_weight?(item)
  !fits_weight?(item)
end

#fits_capacity?(item) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/haversack/sack.rb', line 35

def fits_capacity?(item)
  item.size <= available_capacity
end

#fits_item?(item) ⇒ Boolean Also known as: fits?

Returns:

  • (Boolean) 


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# File 'lib/haversack/sack.rb', line 43

def fits_item?(item)
  item.is_a?(Haversack::Item) && fits_capacity?(item) && fits_weight?(item)
end

#fits_weight?(item) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/haversack/sack.rb', line 27

def fits_weight?(item)
  item.weight <= available_weight
end

#push(item) ⇒ Object

TODO: Describe which constraint failed



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# File 'lib/haversack/sack.rb', line 48

def push(item) ## TODO: Describe which constraint failed
  fits_item?(item) ? super : raise(Haversack::KnapsackContentError)
end