Class: Sheng::DataSet

Inherits:
Object
  • Object
show all
Defined in:
lib/sheng/data_set.rb

Defined Under Namespace

Classes: KeyNotFound

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hsh) ⇒ DataSet

Returns a new instance of DataSet.

Raises:

  • (ArgumentError) 


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# File 'lib/sheng/data_set.rb', line 7

def initialize(hsh)
  raise ArgumentError.new("must be initialized with a Hash") unless hsh.is_a?(Hash)
  @raw_hash = hsh.deep_symbolize_keys
end

Instance Attribute Details

#raw_hash ⇒ Object

Returns the value of attribute raw_hash.



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# File 'lib/sheng/data_set.rb', line 5

def raw_hash
  @raw_hash
end

Instance Method Details

#fetch(key, **options) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/sheng/data_set.rb', line 20

def fetch(key, **options)
  raise ArgumentError.new("must provide a string") unless key.is_a?(String)
  key_parts = key.split(/\./)
  current_result = raw_hash

  key_parts.each_with_index do |key_part, i|
    begin
      value = current_result.fetch(key_part.to_sym)
    rescue KeyError
      if options.has_key?(:default)
        value = options[:default]
      else
        raise KeyNotFound, "#{key} (at #{key_part})"
      end
    end
    if (i + 1) < key_parts.length
      raise_key_too_long(key, key_part) if !(value.is_a?(Hash))
    end
    current_result = value
  end

  raise_key_too_short(key) if current_result.is_a?(Hash)
  current_result
end

#raise_key_too_long(key, key_part) ⇒ Object

Raises:



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# File 'lib/sheng/data_set.rb', line 12

def raise_key_too_long(key, key_part)
  raise KeyNotFound, "in #{key}, #{key_part} did not return a Hash"
end

#raise_key_too_short(key) ⇒ Object

Raises:



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# File 'lib/sheng/data_set.rb', line 16

def raise_key_too_short(key)
  raise KeyNotFound, "result at #{key} is a Hash"
end