Split long strings without breaking word

1
votes

I have to display multiple long strings (with different length), but I can only display chunks of strings that need them to be between 275 and 295 characters.

So if I have a 3000 words string, It'd be displayed in about 10 pieces.

I'm looking for a way to find the next blank. For example: 

if str[275] != " "
  # find next blank
  p str[0..next_blank]
else
  p str[0..275]
end

I thought of finding the index of the next blank in the 275-295th characters range, but I couldn't find how to do it in Ruby.

Any help will be much appreciated !

2
rubystring
Arbitrarily between 275 and 295 characters? Or 295 max? Inclusive or exclusive? – JonB

2 Answers

2
votes

Rails has a method word_wrap which uses a simple regular expression:

str = 'Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint obcaecat cupiditat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.'

puts str.gsub(/(.{1,80})(\s+|$)/, "\\1\n")

Output:

Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor
incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud
exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute
iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
pariatur. Excepteur sint obcaecat cupiditat non proident, sunt in culpa qui
officia deserunt mollit anim id est laborum.

The regular expression matches (and captures) up to 80 characters (.{1,80}) that are followed by whitespace or end-of-line (\s+|$).

1
votes

Not using regular expresions, tear the input apart and put it back together:

str = 'Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint obcaecat cupiditat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.'

def reformat_wrapped(s, width=78)
  lines = []
  line = ""
  s.split(/\s+/).each do |word|
    if line.size + word.size >= width
      lines << line
      line = word
    elsif line.empty?
      line = word
    else
      line << " " << word
    end
  end
  lines << line if line
  return lines.join "\n"
end

#=>puts reformat_wrapped(str, 78)

Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor
incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat.
Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu fugiat
nulla pariatur. Excepteur sint obcaecat cupiditat non proident, sunt in culpa
qui officia deserunt mollit anim id est laborum.