How to parse JSON strings with single quotes (') in Ruby?

Question

I am trying to parse a JSON String like this:

JSON.parse("{'foo' : 42 }")

However, this yields a JSON::ParseError:

JSON::ParserError: 757: unexpected token at '{'foo' : 42 }'
    from /Users/nils/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/json/common.rb:155:in `parse'
    from /Users/nils/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/json/common.rb:155:in `parse'
    from (irb):2
    from /Users/nils/.rvm/rubies/ruby-2.1.2/bin/irb:11:in `<main>'

I think it expects the ' character to be a " character. Since I have multiple gigabytes of such files I would like to make the parser work with this. Since some of the values may also include ' characters I can't simply run search and replace over them because that may destroy the original content.

Any suggestions on how to make the JSON parser parse this?

Answer 1

I am trying to parse a JSON String like this:

JSON.parse("{'foo' : 42 }")

That's not a JSON string.

However, this yields a JSON::ParseError:

Which is correct, since the string is not JSON.

Any suggestions on how to make the JSON parser parse this?

You cannot parse this with a JSON parser because it's not JSON.

You need to figure out what language it is, and then use a parser for that language.

The snippet you posted looks like YAML, but of course that could just be accidental.

require 'yaml'

YAML.load("{'foo' : 42 }")
# => { "foo" => 42 }

But note that trying to guess the language from one single, short example is highly error-prone. You should confer with the producer of that serialization and ask them what language it is.