Question

The following…

require 'yaml' test = 'I'm a b&d string' File.open('test.yaml', 'w') do |out|   out.write(test.to_yaml) end 

…outputs …

--- this is a b&d string 

How can I get it to output

--- 'this is a b&d string' 

???

Answer 1

If you want to store an escaped string in YAML, escape it using #inspect before you convert it to YAML:

irb> require 'yaml' => true irb> str = %{This string's a little complicated, but it 'does the job' (man, I hate scare quotes)} => 'This string's a little complicated, but it \'does the job\' (man, I hate scare quotes)' irb> puts str This string's a little complicated, but it 'does the job' (man, I hate scare quotes) => nil irb> puts str.inspect 'This string's a little complicated, but it \'does the job\' (man, I hate scare quotes)' => nil irb> puts str.to_yaml --- This string's a little complicated, but it 'does the job' (man, I hate scare quotes) => nil irb> puts str.inspect.to_yaml --- '\'This string's a little complicated, but it \\\'does the job\\\' (man, I hate scare quotes)\'' => nil 

YAML doesn’t quote strings unless it has to. It quotes strings if they include things that it would miss if it stored it unquoted – like surrounding quote characters or trailing or leading spaces:

irb> puts (str + ' ').to_yaml --- 'This string's a little complicated, but it \'does the job\' (man, I hate scare quotes) ' => nil irb> puts %{'#{str}'}.to_yaml --- '\'This string's a little complicated, but it \'does the job\' (man, I hate scare quotes)\'' => nil irb> puts (' ' + str).to_yaml --- ' This string's a little complicated, but it \'does the job\' (man, I hate scare quotes)' => nil 

However, as a YAML consumer, whether the string is quoted shouldn’t matter to you. You should never be parsing the YAML text yourself – leave that to the libraries. If you need the string to be quoted in the YAML file, that smells bad to me.

It doesn’t matter whether your strings have ‘&’s in them, YAML will preserve the string:

irb> test = 'I'm a b&d string' => 'I'm a b&d string' irb> YAML::load(YAML::dump(test)) => 'I'm a b&d string' irb> YAML::load(YAML::dump(test)) == test => true