The “official” syntax diagrams on json.org don’t show support for comments, although I believe comments are supported by JavaScript’s eval() - at least they are in Firefox.

As for the string parsing, no - I’m not at all sure if it parses them according to the JavaScript/JSON syntax. I know it uses Haskell syntax, one might be a superset of the other and although it is easy to check, I didn’t. I thought about this when writing the blog post but decided to gloss over it.

The reason is that the post’s main purpose is to show an example of how easy it is to construct parsers using Parsec. JSON is a well understood language that serves as a good example, but since the JSON part came second after showing parser usage - I allwed myself to take some liberties with it :)

In any case, if you need a proper Haskell JSON library, take a look at the links in the last paragraph.

But does JSON really support comments? I haven’t found any reference to comments in rfc4627. Also, and this is probably nitpicking, are you sure stringLiteral parses the exact syntax of JSON strings?