[olavk]

What you have done in you example is reinvent XML with round parenthesis instead of pointy brackets. Why is this better? The only difference is that you leave out the redundant end tags, which are there for good reason.

Yes, XML requires a library to parse - so does s-expressions! The reason XML seem more complex than sexprs is that it defines a higher-level syntax e.g. with element/attribute-distinctions. You have reinvented that yourself in you example, so you need a spec for it and you need the parser to support it. Also the rules of encodings and character sets have to be specified (e.g. how do you detect the encoding of a file? Which characters count as whitespace?). You will end up with a spec much like XML, except with round parentheses. (OK, XML is also complex because of DTD's but that is a optional part. If you want something like DTD's for sexprs, again, you have to specify it, and you get something like XML.)

Btw. there is no heuristics for recovery in XML. XML parsers must fail when encountering malformed syntax. This is one of the major (and controversial) differences between XML and HTML.

I appreciate s-expressions as a syntax for a programming language. But code is a very different use case than documents. I wouldn't like to program in XML syntax either! E.g. programs (hopefully) don't have deeply nested structures covering several pages. That is common in documents, hence the importance of the redundant end tag.

I like sexprs for code and data, but for documents they are only simpler if you ignore a lot of real-world issues.

[13ren]

Megginson's essay "All markup ends up looking like XML" compares XML, JSON and s-exp

http://www.megginson.com/blogs/quoderat/2007/01/03/all-marku...