Markdown Extra Spec: Parsing Section

[John MacFarlane]

> And I was under the impression that you had given me a nearly complete  

> cheatsheet of the PEG grammar in that previous email. What does $, ->>, 

> <++>, and ## mean?


Sorry, these are not standard PEG symbols, but they are used in the
Haskell PEG library I'm using (Frisby). If you look at the source code
of Markdown.hs, you'll find a table correlating Frisby notation with
standard PEG notation:
http://github.com/jgm/markdown-peg/tree/master/Markdown.hs#L69

The only symbol not explained there is '$'. '$' is a standard Haskell sign
for function application; basically it's just a way to write things with
fewer parentheses. So, for example,

    newRule $ blah blah blah

is the same as

    newRule (blah blah blah)

John