Module: FatCore::Array

Included in:
Array
Defined in:
lib/fat_core/array.rb

Overview

Useful extensions to the core Array class.

Instance Method Summary collapse

Instance Method Details

#comma_join(sep: nil, last_sep: nil, two_sep: nil) ⇒ Object

Convert this array into a single string by (1) applying #to_s to each element and (2) joining the elements with the string given by the sep: parameter. By default the sep parameter is ', '. You may use a different separation string in the case when there are only two items in the list by supplying a two_sep parameter. You may also supply a difference separation string to separate the second-last and last items in the array by supplying a last_sep: parameter. By default, the sep parameter is the string ', ', the two_sep is ' and ', and the last_sep is ', and ', all of which makes for a well-punctuated English clause. If sep is given, the other two parameters are set to its value by default. If last_sep is given, two_sep takes its value by default. If the input array is empty, #comma_join returns an empty string.



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# File 'lib/fat_core/array.rb', line 48

def comma_join(sep: nil, last_sep: nil, two_sep: nil)
  orig_sep = sep
  orig_last_sep = last_sep
  sep ||= ', '
  last_sep ||= orig_sep || ', and '
  two_sep ||=  orig_sep || orig_last_sep || ' and '
  result = +''
  case size
  when 0
    result
  when 1
    result = self[0].to_s
  when 2
    result = self[0].to_s + two_sep + self[1]
  else
    second_last = size - 2
    last = size - 1
    each_with_index do |itm, k|
      result <<
        if k == second_last
          "#{itm}#{last_sep}"
        elsif k == last
          itm.to_s
        else
          "#{itm}#{sep}"
        end
    end
  end
  result
end

#diff_with_dups(*others) ⇒ Object

Return an Array that is the difference between this Array and +other+, but without removing duplicates as the Array#- method does. All items of this Array are included in the result unless they also appear in any of the +other+ Arrays.



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# File 'lib/fat_core/array.rb', line 28

def diff_with_dups(*others)
  result = []
  each do |itm|
    result << itm if others.none? { |oth| oth.include?(itm) }
  end
  result
end

#intersect_with_dups(*others) ⇒ Object

Return a new Array that is the intersection of this Array with all +others+, but without removing duplicates as the Array#& method does. All items of this Array are included in the result but only if they also appear in all of the other Arrays.



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# File 'lib/fat_core/array.rb', line 16

def intersect_with_dups(*others)
  result = []
  each do |itm|
    result << itm if others.all? { |oth| oth.include?(itm) }
  end
  result
end

#last_i ⇒ Object

Return the index of the last element of this Array. This is just a convenience for an oft-needed Array attribute.



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# File 'lib/fat_core/array.rb', line 8

def last_i
  size - 1
end