Method: Immutable::Vector#insert

Defined in:
lib/immutable/vector.rb

#insert(index, *items) ⇒ Vector

Return a new Vector with the given values inserted before the element at index. If index is greater than the current length, nil values are added to pad the Vector to the required size.

Examples:

Immutable::Vector["A", "B", "C", "D"].insert(2, "X", "Y", "Z")
# => Immutable::Vector["A", "B", "X", "Y", "Z", "C", "D"]
Immutable::Vector[].insert(2, "X", "Y", "Z")
# => Immutable::Vector[nil, nil, "X", "Y", "Z"]

Raises:

  • (IndexError) —

    if index exceeds negative range.



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# File 'lib/immutable/vector.rb', line 356

def insert(index, *items)
  raise IndexError if index < -@size
  index += @size if index < 0

  if index < @size
    suffix = flatten_suffix(@root, @levels * BITS_PER_LEVEL, index, [])
    suffix.unshift(*items)
  elsif index == @size
    suffix = items
  else
    suffix = Array.new(index - @size, nil).concat(items)
    index = @size
  end

  replace_suffix(index, suffix)
end