YAML: error parsing a string with escaped double quote

Question

Ruby 2.0, Yaml using Psych seems to have trouble escaping double quotes. Anyone have an idea on resolving this?

data_ =<<END_
description: "Acme acquires ILM: Lucas says \"Inevitable!\""
END_

ap YAML.load(data_)

produces

    /Users/x/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/psych.rb:205:in `parse': (<unknown>): did not find expected key while parsing a block mapping at line 1 column 1 (Psych::SyntaxError)    

Escaping the entry with single quotes works, but if it contains single quotes, escaping them results in an error, too.

description: 'Acme acquires ILM: Lucas says "It\'s Inevitable!"'

In an ideal world, the entries would contain proper unicode typographical quotes, but I don't have control over these (although I could replace them before processing with YAML)...

Any ideas on having YAML parse this properly?

Update: answering my question. Found out that it is possible to escape a single quote by duplicating it, so this works:

description: 'Acme acquires ILM: Lucas says "It''s Inevitable!"'

I discovered this by using YAML.dump(the-desired-string)

Answer 1

Your problem is that heredocs act like double quoted strings as far as escaping is concerned. That means that a \" in your heredoc ends up as just " in your string. Observe:

>> data_ =<<END_
description: "Acme acquires ILM: Lucas says \"Inevitable!\""
END_
>> puts data_
description: "Acme acquires ILM: Lucas says "Inevitable!""

You want to get a \ into the YAML string so you'll have to escape it:

data_ =<<END_
description: "Acme acquires ILM: Lucas says \\"Inevitable!\\""
END_

Alternatively, use %q{...} to quote your string so that it behaves more like a single quoted string:

data_ = %q{
description: "Acme acquires ILM: Lucas says \"Inevitable!\""
}