Class: HandySort::Ranker

Inherits:
Object
  • Object
show all
Defined in:
lib/handy_sort/ranker.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ Ranker

Returns a new instance of Ranker.



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# File 'lib/handy_sort/ranker.rb', line 5

def initialize(key)
  @key = key.to_sym
end

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/handy_sort/ranker.rb', line 3

def key
  @key
end

Instance Method Details

#move_affected(relation, old_val, new_val) ⇒ Object 



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# File 'lib/handy_sort/ranker.rb', line 9

def move_affected(relation, old_val, new_val)
  affected = relation.where(key => Range.new(*[old_val, new_val].sort))
  offset = old_val > new_val ? 1 : -1

  affected.update_all "%s = %s + (%d)" % [key.to_s, key.to_s, offset]
end