Utility script for publishing Markdown Extra documents as Gist

00README.md

While Gist's markdown flavor is a superset of basic Markdown, it's not exactly the same as Markdown Extra.

To publish documents written in Markdown Extra as Gist so that it looks good:

1. Convert the document to basic Markdown with Pandoc:

$ pandoc -f markdown -t markdown_strict ```

2. Run the resulting document through this script to emulate Markdown Extra features in a Gist compatible way.

Note:

• the script relies on Pandoc's formatting conventions for dumbing down extra constructs to basic, so it can be expected to work only with Pandoc produced basic Markdown
• the script relies on some particularities of Gist's way to generate HTML from Markdown, so the result can be expected to look good only on Gist
• needless to say it's a hack, not tested thoroughly

markdown-enhance.rb

#!/usr/bin/env ruby

# enhance (Pandoc-normalized) basic markdown
# to emulate markdown-extra

require 'ap'

SUP = %w[⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹]

ma = []

doc = $<.read


# replace [<index>] type dead footnotes with
# superscripted back-and-forth links
doc.gsub!(/\[(\d+)\]/) { |m|
  n = Integer $1
  ma[n] ||= 0
  ma[n] += 1
  case ma[n]
  when 1
    %[<a name="fni-#{n}"/>[#{SUP[n]}](#fnb-#{n})]
  when 2
    %[<a name="fnb-#{n}"/>[^#{SUP[n]}](#fni-#{n})]
  else
    m
  end
}

# generate toc with Gist-style section ids
if doc =~ /\[TOC\]/m
  t = nil
  ha = []
  doc.each_line { |l|
    if l =~ /^(#+)\s(.*)/
      ha << [$1.size, $2]
    elsif t
      case l
      when /^---/
        ha << [2, t]
      when /^===/
        ha << [1, t]
      end
    end
    t = l.strip
  }
  doc.gsub! "[TOC]", ha.map { |d,t| "#{"    " * (d-1)}  - [#{t}](##{t.downcase.gsub(/[^a-zA-Z ]/, "").gsub(" ", "-")})\n" }.join
end

# hack to fix some Pandoc-Gist incompatibility
# XXX this is pretty narrow this way, I wonder if it could be gerenalized
doc.gsub!(/\(\*([^*]+)\*\)/) { "( *#{$1.gsub "\\", ""}* )" }

$> << doc