module Elipsa

@param str [String] @param options [Hash{Symbol=>Object}] @option options [Integer] :length (80)

The maximum length of the result string,
including an ellipsis if present.

@option options [String] :symbol (‘…’)

The string to use as an ellipsis symbol

@option options [Numeric] :ratio (7/8)

The ratio of available space that the
resulting string must fill, if truncated.
This ensures that if a word-boundary is
not found close enough to your length
to make the result meaningful, the string
is broken mid-word instead.

# File lib/elipsa.rb, line 22
def elipsa(str, options = {})
  max_length = options.fetch(:length) { 80 }
  return str if str.length <= max_length

  symbol = options.fetch(:symbol) { '...' }
  available = max_length - symbol.length
  ratio = options.fetch(:ratio) { Rational(7, 8) }

  substr = str[/\A(.{0,#{available}})(?=\b\W+)/mu] || ''

  if Rational(substr.length, available) < ratio
    substr = str[0...available]
  end

  "#{substr}#{symbol}"
end