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Comment by Groxx | Hacker News Reader

The spec. The spectacle. This fall, only on Twitter!

I see the assertion that:

>MMD has a very clear specification. It also has an openly available test suite.

But the specification link goes to the help page [1] which as far as I can tell has no spec, just links to descriptions (Gruber's canonical blog post) and examples. Is there an actual spec for MMD, or are they claiming examples are specs?

[1]: http://fletcherpenney.net/multimarkdown/help/

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There is a test suite [1] available, though. Furthermore, the core of MMD is in the PEG grammar [2], which is enough of a specification for me. Compatibility of language subsets is even provable, so specifying a MMD-lite version (which might be the vanilla Markdown features) would be simple. On the other hand, I think its flexibility/sanity is actually a disadvantage for MMD: with the confusion and variability of a spec-free language that is still roughly familiar (i.e. Markdown), people seem more likely to adopt it with their own implementations and customizations.

[1]: https://github.com/fletcher/MMD-Test-Suite

[2]: https://github.com/fletcher/peg-multimarkdown/blob/master/ma...

The grammar is not enough. You also need to specify the output of the HTML transformation.

That's just a grammar though. It's meaningless without defining what the result is, because you could use that grammar to output anything. A spec should also (ideally) define all possible behavior, so you know if something is conforming or not.

Looking at the site, it seems like MMD is Yet Another Markdown Implementation. Which is a good reason to participate, and they might have some particularly good things to contribute (like a test suite), but it's not itself "standard Markdown". And even the test suite probably is overly specific and needs to be reviewed. For instance, it seems unlikely that balanced quotes would become a required feature (or at least to do so would require discussion).

Maybe he is referencing the pdf: http://fletcher.github.com/peg-multimarkdown/mmd-manual.pdf

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