diff --git a/bb_postindex.rb b/bb_postindex.rb
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+#!/usr/bin/ruby
+
+# BB_POSTINDEX.RB makes a neat post collection index for Xenforo2 forum
+# posts. Write the post summary text followed by the post URL in
+# any (raw) text editor, with a single newline separating the summary
+# from the URL, but as many blank lines as you want separating each
+# post summary. Optionally, prefix the summary with specific commands
+# to force different output formatting:
+#   - !extra categorizes the comment as an extra to be placed at
+#     the end of the post collection for the day,
+#   - !daystart specifies that the following posts should be placed
+#     inside spoiler tags given by the specified day (see example).
+#   - !dayend similarly signals the end of the spoiler tags.
+#
+#  Example: So the text files I write to sort posts look like:
+#
+#    !daystart Saturday, 15 February 2020
+#
+#    Oh, snap! Things just got real ((@UserName) post)
+#    https://blahblahblah/page-12#post-3456789
+#
+#    !extra (@WinnerPoster) made an interesting comment
+#    https://blahblahblah/page-13#post-4214133
+#
+#    !dayend
+#
+# Then running this script with formats the posts with hyperlinks
+# to the posts, @'s for the credited users, and puts everything
+# behind spoiler tags separating the days. Within each day, the
+# normal posts are formatted with bullet points and a sans serif
+# font for whimsy, and the extra posts appear in a separate section
+# "Informative takes and extras:" at the end of the spoiler.
+
+# For whimsy, use Arial san serif font for the main post list.
+LIST_FORMAT_FONT = "arial"
+
+# Use text macros to dictate the format of the post collection index.
+# !daystart begins a spoiler tag for a given day
+DAY_START = "!daystart"
+
+# !dayend ends the spoiler tag for a given day
+DAY_END = "!dayend"
+
+# !extra specifies that the post is an informative extra, to appear
+# separately in a list at the end
+EXTRA = "!extra"
+
+
+# A class to represent an INDEXEDPOST with a given summary, user,
+# and post hyperlink. Optionally, the post may be specified as
+# an 'extra', in which case no list-style bullet point and sans
+# serif formatting is applied.
+#
+# Example:
+#   # Create a new indexed post and print it in default list format
+#   post1 = IndexedPost.new("List post (@User post)", "@User", "www.blah#p-1")
+#   puts post1  #=> [FONT=arial][URL='www.blah#p-1']○ List post ([/URL]
+#               #   @User[URL='www.blah#p-1'] post)[/URL][/FONT]
+#
+#   # Create a new indexed post and print it in extra format
+#   post2 = IndexedPost.new("@User's extra post", "@User", "www.blah", true)
+#   puts post2  #=> @User[URL='www.blah']'s extra post[/URL]
+#   # And in list form:
+#   puts post2.list_format  #=> [FONT=arial][URL='www.blah']○ [/URL]
+#                           #@User[URL='www.blah']'s extra post[/URL][/FONT]
+#
+class IndexedPost
+
+  # Create a new indexed post with the given SUMMARY, USER and
+  # POST_HYPERLINK. If EXTRA is true, formats the post as an
+  # informative extra without any explicit list formatting.
+  def initialize(summary, user, post_hyperlink, extra=false)
+    @summary = summary
+    @user = user
+    @post_hyperlink = post_hyperlink
+    @extra = extra
+  end
+
+  # Return a string representation for this post in extra format,
+  # i.e. in the regular font with just the hyperlink and no
+  # additional formatting.
+  def extra_format()
+    text = @summary.split(@user).map do |part|
+      if (part.length > 0)
+        "[URL='" + @post_hyperlink + "']" + part + "[/URL]"
+      end
+    end
+    text.join(" " + @user + " ")
+  end
+  
+  # Return a string representation for this post in list format,
+  # i.e. in sans serif font with an ASCII bullet point prepended.
+  # TODO: These methods are very similar. Refactor to get rid of the
+  #       code duplication at some point later?
+  def list_format()
+    text = ("○ " + @summary).split(@user).map do |part|
+      if (part.length > 0)
+        "[URL='" + @post_hyperlink + "']" + part + "[/URL]"
+      end
+    end
+    "[FONT=" + LIST_FORMAT_FONT + "]" + text.join(" " + @user + " ") + "[/FONT]"
+  end
+  
+  # Return the printable string representation for this indexed post.
+  def to_s()
+    if (@extra)
+      self.extra_format
+    else
+      self.list_format
+    end
+  end
+  
+end
+
+
+# Assume that the file full of posts is the first command line arg
+if (ARGV.length < 1)
+  raise(ArgumentError, "No post file specified in command line args")
+else
+  posts_file = File.open(ARGV.join(""))
+end
+
+# Read lines from the post collection file (ignoring blank lines), and
+# generate the index structure.
+list_posts = []
+extra_posts = []
+day_active = false
+
+line = posts_file.gets.strip
+
+while (line)
+  # Skip any preceding white space or blank lines
+  line.strip!
+  if (not line.empty?)
+    case
+    when line.start_with?(DAY_START)
+      # Start the spoiler tag and refresh the post lists
+      puts "[SPOILER=\"" + line.split(DAY_START)[1].strip! + "\"]"
+      list_posts = []
+      extra_posts = []
+      day_active = true
+      
+    when line.start_with?(DAY_END)
+      # Print all of the collected list posts
+      list_posts.map { |post| puts post.list_format }
+      
+      # Print all of the collected extra posts in a separate section
+      puts "\nInformative takes and extras:"
+      extra_posts.map { |post| puts post.extra_format }
+
+      # Finally, end the spoiler tag
+      puts "[/SPOILER]"
+      day_active = false
+
+    else
+      # If the line begins with !extra, it's an extra/informative post
+      extra = line.start_with?(EXTRA)
+      if (extra)
+        line = line.split(EXTRA)[1].strip
+      end
+
+      # Parse the user name (assumed to be between a pair of parentheses
+      # for simplicity)
+      user_with_parens = line.scan(/\(@.+\)(?=['\s])/)[0].strip
+      user = user_with_parens[1..-2]
+
+      # And remove the extra parentheses in the formatted summary
+      summary = line.gsub(user_with_parens, user)
+      
+      # Grab the next line too for the hyperlink
+      post_hyperlink = posts_file.gets.strip
+
+      # Instantiate a new post index and add it to the list.
+      indexed_post = IndexedPost.new(summary, user, post_hyperlink, extra)
+      if (extra)
+        extra_posts << indexed_post
+      else
+        list_posts << indexed_post
+      end
+    end
+  end
+
+  # Read in the next line
+  line = posts_file.gets
+end
+
+# Done reading! Close the collected posts file.
+posts_file.close()
+
+# Check: at the end here, if we still have collected posts for the day,
+# print them all now and close the spoiler tag.
+if (day_active)
+  # TODO: Duplicate code from the case. Refactor?
+  # Print all of the collected list posts
+  list_posts.map { |post| puts post.list_format }
+  
+  # Print all of the collected extra posts in a separate section
+  puts "\nInformative takes and extras:"
+  extra_posts.map { |post| puts post.extra_format }
+  
+  # Finally, end the spoiler tag
+  puts "[/SPOILER]"
+end
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