Module: Hamstar

Defined in:
lib/hamstar.rb,
lib/hamstar/version.rb

Constant Summary collapse

KLEENE_STAR = 
'*'
VERSION = 
"0.0.3"

Class Method Summary collapse

Class Method Details

.association(c, *key_path, &block) ⇒ Object 



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# File 'lib/hamstar.rb', line 39

def association(c, *key_path, &block)
  key,value = key_path[0]
  kp_rest = Hamster.from(key_path)[1..-1] # drop assoc
  c.each_pair do |k,v|
    if v[key] == value
      kp = kp_rest.unshift k # put key where assoc was
      c = update_having c, *kp, &block
    end
  end
  c
end

.kleene_star(c, *key_path, &block) ⇒ Object 



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# File 'lib/hamstar.rb', line 30

def kleene_star(c, *key_path, &block)
  kp_rest = Hamster.from(key_path)[1..-1] # drop kleene star
  c.keys.each do |key|
    kp = kp_rest.unshift key # put key where kleene star was
    c = update_having c, *kp, &block
  end
  c
end

.update_having(c, *key_path, &block) ⇒ Object 



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# File 'lib/hamstar.rb', line 11

def update_having(c, *key_path, &block)
  if key_path.empty?
    raise ArgumentError, "must have at least one key in path"
  end
  key = key_path[0]
  case key
  when KLEENE_STAR; kleene_star c, *key_path, &block
  when Array, Hamster::Vector; association c, *key_path, &block
  else
    if key_path.size == 1
      new_value = block.call c.fetch(key,nil)
    else
      value = c.fetch key, Hamster::EmptyHash
      new_value = update_having value, *key_path[1..-1], &block
    end
    c.put key, new_value
  end
end