From 36ba1742245bc5e294d792b9193de07c628e1387 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= <essen@ninenines.eu>
Date: Tue, 22 Oct 2013 09:10:24 +0200
Subject: Convert the markdown_middleware example to a release

---
 examples/markdown_middleware/Makefile              |    6 +
 examples/markdown_middleware/README.md             |   35 +-
 examples/markdown_middleware/rebar.config          |    8 -
 examples/markdown_middleware/relx.config           |    2 +
 examples/markdown_middleware/src/erlmarkdown.erl   | 1581 ++++++++++++++++++++
 .../markdown_middleware/src/markdown_converter.erl |    4 +-
 .../src/markdown_middleware.erl                    |   15 -
 .../src/markdown_middleware_app.erl                |    6 +-
 examples/markdown_middleware/start.sh              |    3 -
 9 files changed, 1614 insertions(+), 46 deletions(-)
 create mode 100644 examples/markdown_middleware/Makefile
 delete mode 100644 examples/markdown_middleware/rebar.config
 create mode 100644 examples/markdown_middleware/relx.config
 create mode 100644 examples/markdown_middleware/src/erlmarkdown.erl
 delete mode 100644 examples/markdown_middleware/src/markdown_middleware.erl
 delete mode 100755 examples/markdown_middleware/start.sh

diff --git a/examples/markdown_middleware/Makefile b/examples/markdown_middleware/Makefile
new file mode 100644
index 0000000..f2e46ac
--- /dev/null
+++ b/examples/markdown_middleware/Makefile
@@ -0,0 +1,6 @@
+PROJECT = markdown_middleware
+
+DEPS = cowboy
+dep_cowboy = pkg://cowboy master
+
+include ../../erlang.mk
diff --git a/examples/markdown_middleware/README.md b/examples/markdown_middleware/README.md
index af7937f..3c63f59 100644
--- a/examples/markdown_middleware/README.md
+++ b/examples/markdown_middleware/README.md
@@ -1,24 +1,25 @@
-Cowboy Middleware
-=================
+Middleware example
+==================
 
-To compile this example you need rebar in your PATH.
+To try this example, you need GNU `make`, `git` and
+[relx](https://github.com/erlware/relx) in your PATH.
 
-Type the following command:
-```
-$ rebar get-deps compile
-```
+To build the example, run the following command:
 
-You can then start the Erlang node with the following command:
-```
-./start.sh
+``` bash
+$ make
 ```
 
-Cowboy will serve all the files you put in the priv/ directory. If you request
-a .html file that has corresponding .md file that has been modified more
-recently than the .html file, the markdown file will be converted to HTML and
-served by Cowboy.
+To start the release in the foreground:
+
+``` bash
+$ ./_rel/bin/hello_world_example console
+```
 
-HTML5 Video Example
--------------------
+Then point your browser at
+[http://localhost:8080/video.html](http://localhost:8080/video.html).
 
-Open http://localhost:8080/video.html in your favorite browser.
+Cowboy will serve all the files you put in the `priv` directory.
+If you request a `.html` file that has a corresponding `.md` file
+that has been modified more recently than the `.html` file, the
+Markdown file will be converted to HTML and served by Cowboy.
diff --git a/examples/markdown_middleware/rebar.config b/examples/markdown_middleware/rebar.config
deleted file mode 100644
index bd34059..0000000
--- a/examples/markdown_middleware/rebar.config
+++ /dev/null
@@ -1,8 +0,0 @@
-{deps, [
-	{cowboy, ".*",
-		{git, "git://github.com/extend/cowboy.git", "master"}},
-	{mimetypes, ".*",
-		{git, "git://github.com/spawngrid/mimetypes.git", "master"}},
-	{erlmarkdown, ".*",
-		{git, "git://github.com/ericbmerritt/erlmarkdown.git", "rv"}}
-]}.
diff --git a/examples/markdown_middleware/relx.config b/examples/markdown_middleware/relx.config
new file mode 100644
index 0000000..9c622b9
--- /dev/null
+++ b/examples/markdown_middleware/relx.config
@@ -0,0 +1,2 @@
+{release, {markdown_middleware_example, "1"}, [markdown_middleware]}.
+{extended_start_script, true}.
diff --git a/examples/markdown_middleware/src/erlmarkdown.erl b/examples/markdown_middleware/src/erlmarkdown.erl
new file mode 100644
index 0000000..6cab50d
--- /dev/null
+++ b/examples/markdown_middleware/src/erlmarkdown.erl
@@ -0,0 +1,1581 @@
+%%% -*- mode: Erlang; fill-column: 80; comment-column: 75; -*-
+%%% Copyright 2012 Erlware, LLC. All Rights Reserved.
+%%%
+%%% This file is provided to you under the Apache License,
+%%% Version 2.0 (the "License"); you may not use this file
+%%% except in compliance with the License.  You may obtain
+%%% a copy of the License at
+%%%
+%%%   http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing,
+%%% software distributed under the License is distributed on an
+%%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%%% KIND, either express or implied.  See the License for the
+%%% specific language governing permissions and limitations
+%%% under the License.
+%%%---------------------------------------------------------------------------
+%%% @copyright (C) Erlware, LLC.
+%%% @copyright (C) 2009, Gordon Guthrie
+%%% @doc
+-module(erlmarkdown).
+
+-export([conv/1,
+         conv_utf8/1,
+         conv_file/2]).
+
+-define(SPACE, 32).
+-define(TAB,    9).
+-define(LF,    10).
+-define(CR,    13).
+-define(NBSP, 160).
+-define(AMP, $&, $a, $m, $p, $;).
+-define(COPY, $&, $c, $o, $p, $y, $;).
+
+%%============================================================================
+%% API
+%%============================================================================
+
+%% the lexer first lexes the input
+%% make_lines does 2 passes:
+%% * it chops the lexed strings into lines which it represents as a
+%%   list of lists
+%% * it then types the lines into the following:
+%% * normal lines
+%% * reference style links
+%% * reference style images
+%% * special line types
+%%   - blank
+%%   - SETEXT header lines
+%%   - ATX header lines
+%%   - blockquote
+%%   - unordered lists
+%%   - ordered lists
+%%   - code blocks
+%%   - horizontal rules
+%% the parser then does its magic interpolating the references as appropriate
+conv(String) ->
+    Lex = lex(String),
+    UntypedLines = make_lines(Lex),
+    {TypedLines, Refs} = type_lines(UntypedLines),
+    parse(TypedLines, Refs).
+
+-spec conv_utf8(list()) -> list().
+conv_utf8(Utf8) ->
+    Str = xmerl_ucs:from_utf8(Utf8),
+    Res = conv(Str),
+    xmerl_ucs:to_utf8(Res).
+
+conv_file(FileIn, FileOut) ->
+    case file:open(FileIn, [read]) of
+        {ok, Device} ->
+            Input = get_all_lines(Device,[]),
+            Output = conv(Input),
+            write(FileOut, Output);
+        _ ->
+            error
+    end.
+
+%%============================================================================
+%% Internal Functions
+%%============================================================================
+
+get_all_lines(Device, Accum) ->
+    case io:get_line(Device,"") of
+        eof  ->
+            file:close(Device),
+            Accum;
+        Line ->
+            get_all_lines(Device,Accum ++ Line)
+    end.
+
+write(File, Text) ->
+    _Return=filelib:ensure_dir(File),
+    case file:open(File, [write]) of
+        {ok, Id} ->
+            io:fwrite(Id, "~s~n", [Text]),
+            file:close(Id);
+        _ ->
+            error
+    end.
+
+
+%%
+%% Parse the lines interpolating the references as appropriate
+%%
+
+parse(TypedLines, Refs) ->
+    string:strip(p1(TypedLines, Refs, 0, []), both, $\n).
+
+%% goes through the lines
+%% Variable 'R' contains the References and 'I' is the indent level
+
+%% Terminal clause
+p1([], _R, _I, Acc) ->
+    lists:flatten(lists:reverse(Acc));
+
+%% Tags have the highest precedence...
+p1([{tag, Tag} | T], R, I, Acc) ->
+    case T of
+        [] ->
+            p1([], R, I, ["</p>", make_tag_str(Tag, R), "<p>" | Acc]);
+        [{blank, _} | T2] ->
+            p1(T2, R, I, [make_tag_str(Tag, R) | Acc]);
+        _Other ->
+            p1(T, R, I, [pad(I) ++ make_tag_str(Tag, R) | Acc])
+    end;
+
+p1([{blocktag, [{{{tag, open}, Type}, Tg}] = _Tag} | T], R, I, Acc) ->
+    {Block, Rest} = grab_for_blockhtml(T, Type, []),
+    Str = lists:flatten([Tg, "\n" | Block]),
+    p1(Rest, R, I, [Str | Acc]);
+
+%% blank lines/linefeeds are gobbled down
+p1([{Type, _} | T], R, I, Acc)
+  when Type == blank orelse Type == linefeed ->
+    Rest = grab_empties(T),
+    p1(Rest, R, I, [pad(I) ++ "\n" | Acc]);
+
+%% two consecutive normal lines should be concatenated...
+%% remembering the pad the second line with the indent...
+p1([{normal, P1}, {normal, P2} | T], R, I, Acc) ->
+    p1([{normal, merge(P1, pad(I), P2)} | T], R, I, Acc);
+%% as should a normal and linefeed
+
+%% setext h1 is a look behind and it overrides blockquote and code...
+p1([{normal, P}, {setext_h1, _} | T], R, I, Acc) ->
+    p1(T, R, I,  [pad(I) ++ "<h1>" ++ make_string(snip(P), R)
+                  ++ "</h1>\n\n" | Acc]);
+p1([{blockquote, P}, {setext_h1, _} | T], R, I, Acc) ->
+    p1(T, R, I,  [pad(I) ++ "<h1>" ++ make_string(snip(P), R)
+                  ++ "</h1>\n\n" | Acc]);
+p1([{{codeblock, P}, _}, {setext_h1, _} | T], R, I, Acc) ->
+    p1(T, R, I,  [pad(I) ++ "<h1>" ++ make_string(snip(P), R)
+                  ++ "</h1>\n\n" | Acc]);
+p1([{blockquote, P}, {h2_or_hr, _} | T], R, I, Acc) ->
+    p1(T, R, I,  [pad(I) ++ "<h2>" ++ make_string(snip(P), R)
+                  ++ "</h2>\n\n" | Acc]);
+p1([{{codeblock, P}, _}, {h2_or_hr, _} | T], R, I, Acc) ->
+    p1(T, R, I,  [pad(I) ++ "<h2>" ++ make_string(snip(P), R)
+                  ++ "</h2>\n\n" | Acc]);
+
+%% but a setext with no lookbehind is just rendered as a normal line,
+%% so change its type and rethrow it
+p1([{setext_h1, P} | T], R, I, Acc) ->
+    p1([{normal, P} | T], R, I, Acc);
+
+%% setext h2 might be a look behind
+p1([{normal, P}, {h2_or_hr, _} | T], R, I, Acc) ->
+    P2 = string:strip(make_string(snip(P), R), both, ?SPACE),
+    p1(T, R, I, [pad(I) ++ "<h2>" ++ P2 ++ "</h2>\n\n" | Acc]);
+
+%% blockquotes swallow each other
+%% replace the first blockquote mark with a space...
+p1([{blockquote, P1}, {blockquote, [_ | P2]} | T], R, I, Acc) ->
+    p1([{blockquote, merge(P1, pad(I), [{{ws, sp}, " "} | P2])} | T], R, I, Acc);
+%% blockquotes swallow normal
+p1([{blockquote, P1}, {normal, P2} | T], R, I, Acc) ->
+    p1([{blockquote, merge(P1, pad(I + 1), P2)} | T], R, I, Acc);
+%% blockquote
+p1([{blockquote, P} | T], R, I, Acc) ->
+    [{{md, gt}, _} | T1] = P,
+    T2 = string:strip(make_string(T1, R)),
+    p1(T, R, I,
+       ["\n<blockquote>\n" ++ pad(I + 1) ++ "<p>" ++ T2 ++ "</p>\n</blockquote>" | Acc]);
+
+%% one normal is just normal...
+p1([{normal, P} | T], R, I, Acc) ->
+    P2 = string:strip(make_string(snip(P), R), both, ?SPACE),
+    p1(T, R, I, [pad(I) ++ "<p>" ++ P2 ++ "</p>\n" | Acc]);
+
+%% atx headings
+p1([{{h1, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h1>" ++ NewP ++ "</h1>\n\n" | Acc]);
+p1([{{h2, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h2>" ++ NewP ++ "</h2>\n\n" | Acc]);
+p1([{{h3, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h3>" ++ NewP ++ "</h3>\n\n" | Acc]);
+p1([{{h4, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h4>" ++ NewP ++ "</h4>\n\n" | Acc]);
+p1([{{h5, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h5>" ++ NewP ++ "</h5>\n\n" | Acc]);
+p1([{{h6, P}, _} | T], R, I, Acc) ->
+    NewP = string:strip(make_string(snip(P), R), right),
+    p1(T, R, I,  [pad(I) ++ "<h6>" ++ NewP ++ "</h6>\n\n" | Acc]);
+
+%% unordered lists swallow normal and codeblock lines
+p1([{{ul, P1}, S1}, {{normal, P2}, S2} | T], R, I , Acc) ->
+    p1([{{ul, merge(P1, pad(I), P2)}, S1 ++ S2} | T], R, I, Acc);
+p1([{{ul, P1}, S1}, {{codeblock, P2}, S2} | T], R, I , Acc) ->
+    p1([{{ul, merge(P1, pad(I), P2)}, S1 ++ S2} | T], R, I, Acc);
+p1([{{ul, _P}, _} | _T] = List, R, I, Acc) ->
+    {Rest, NewAcc} = parse_list(ul, List, R, I, [], false),
+    p1(Rest, R, I,  [pad(I) ++ "<ul>\n" ++ NewAcc
+                     ++ pad(I) ++ "</ul>\n" | Acc]);
+
+%% ordered lists swallow normal and codeblock lines
+p1([{{ol, P1}, S1}, {{normal, P2}, S2} | T], R, I , Acc) ->
+    p1([{{ol, merge(P1, pad(I), P2)}, S1 ++ S2} | T], R, I, Acc);
+p1([{{ol, P1}, S1}, {{codeblock, P2}, S2} | T], R, I , Acc) ->
+    p1([{{ol, merge(P1, pad(I), P2)}, S1 ++ S2} | T], R, I, Acc);
+p1([{{ol, _P}, _} | _T] = List, R, I, Acc) ->
+    {Rest, NewAcc} = parse_list(ol, List, R, I, [], false),
+    p1(Rest, R, I,  [pad(I) ++ "<ol>\n" ++ NewAcc
+                     ++ pad(I) ++ "</ol>\n" | Acc]);
+
+%% codeblock consumes any following empty lines
+%% and other codeblocks
+p1([{{codeblock, P1}, S1}, {{codeblock, P2}, S2} | T], R, I, Acc) ->
+    p1([{{codeblock, merge(P1, pad(I), P2)}, S1 ++ S2} | T], R, I, Acc);
+p1([{{codeblock, P}, _} | T], R, I, Acc) ->
+    Rest = grab_empties(T),
+    p1(Rest, R, I,  ["<pre><code>" ++ make_string(snip(P), R)
+                     ++ "\n</code></pre>\n\n" | Acc]);
+
+%% horizontal rules
+p1([{hr, _} | T], R, I, Acc) ->
+    p1(T, R, I,  ["<hr />" | Acc]);
+%% h2_or_hr is greedy for normal lines
+p1([{h2_or_hr, P1}, {normal, P2} | T], R, I, Acc) ->
+    p1([{normal, lists:flatten([P1 | P2])} | T], R, I, Acc);
+%% the clause with a normal before an 'h2_or_hr' has already been
+%% handled further up the tree, so this is a bona fide 'hr'...
+p1([{h2_or_hr, _} | T], R, I, Acc) ->
+    p1(T, R, I,  ["<hr />" | Acc]);
+
+%% Now start pulling out inline refs etc, etc
+p1([{inlineref, _P} | T], R, I, Acc) ->
+    p1(T, R, I, Acc).
+
+grab_for_blockhtml([], Type, Acc) ->
+    {lists:reverse(["</" ++ Type ++ ">" | Acc]), []};
+grab_for_blockhtml([{blocktag, [{{{tag, close}, Type}, Tg}]}
+                    | T], Type,  Acc) ->
+    {lists:reverse([Tg | Acc]), T};
+grab_for_blockhtml([{blocktag, [{{{tag, _}, GrabType}, Tg}]}
+                    | T], Type,  Acc) when GrabType =/= Type ->
+    %% blocktags grabbed in a blocktag need a line ending pushed
+    grab_for_blockhtml(T, Type, ["\n", Tg | Acc]);
+grab_for_blockhtml([{tag, {{{tag, self_closing}, _Ty}, Tg}}
+                    | T], Type, Acc) ->
+    grab_for_blockhtml(T, Type, [Tg | Acc]);
+grab_for_blockhtml([H | T], Type, Acc) ->
+    {_Type, Content} = H,
+    Str = make_plain_string(Content),
+    grab_for_blockhtml(T, Type, [Str | Acc]).
+
+grab_empties([{linefeed, _} | T]) -> grab_empties(T);
+grab_empties([{blank, _} | T])    -> grab_empties(T);
+grab_empties(List)                -> List.
+
+merge(P1, Pad, P2) ->
+    NewP1 = make_br(P1),
+    lists:flatten([NewP1, {string, Pad} | P2]).
+
+make_br(List) -> make_br1(lists:reverse(List)).
+
+make_br1([{{lf, _}, _},
+          {{ws, comp}, _} | T]) -> lists:reverse([{tags, " <br />\n"} | T]);
+make_br1([{{lf, _}, _},
+          {{ws, tab}, _} | T])  -> lists:reverse([{tags, " <br />\n"} | T]);
+make_br1(List)                  -> lists:reverse(List).
+
+pad(N) ->
+    pad1(N, []).
+
+pad1(0, Acc) ->
+    Acc;
+pad1(N, Acc)
+  when N > 0 ->
+    pad1(N - 1, ["  " | Acc]).
+
+%% this is a bit messy because of the way that hard lines are treated...
+%% If your li's have a blank line between them the item gets wrapped in a para,
+%% if not, they don't
+%% BUT if one item is <p> wrapped then the next is too
+parse_list(_Type, [], _R, _I, A, _) ->
+    {[], lists:reverse(A)};
+parse_list(Type, [{{Type, P}, _} | T], R, I, A, Wrap) ->
+    {Rest, NewP, NewWrap} = grab(T, R, [], Wrap),
+    Li =
+        case NewWrap of
+            false ->
+                Ret = parse([{normal, P}], R),
+                %% need to strip off the extra <p></p>'s
+                Ret2 = string:left(Ret, length(Ret) - 4),
+                Ret3 = string:right(Ret2, length(Ret2) -3),
+                Ret3 ++ "\n" ++ NewP ++ pad(I);
+            true  ->
+                string:strip(parse([{normal, P}], R), right, ?LF)
+                    ++ NewP ++ pad(I)
+        end,
+    NewWrap2 =
+        case T of
+            []  ->
+                false; % doesnt matter
+            [H2 | _T2] ->
+                case H2 of
+                    {linefeed, _} ->
+                        true;
+                    _  ->
+                        false
+                end
+        end,
+    parse_list(Type, Rest, R, I, [pad(I) ++ "<li>"
+                                  ++ string:strip(Li, right, ?LF)
+                                  ++ "</li>\n" | A], NewWrap2);
+parse_list(_Type, List, _R, _I, A, _) ->
+    {List, lists:reverse(A)}.
+
+%% grab grabs normals, double codeblocks, linefeeds and blanks
+%% BUT stop grabbing if a normal if preceeded by a linefeed or blank
+%% UNLESS the normal starts with white space :(
+%% the third return parameter is 'true' if the 'li' should be
+%% wrapped in '<p></p>' and false if it shouldn't
+grab([{{codeblock, _}, S} | T] = List, R, Acc, W) ->
+    case is_blockquote(S, T) of
+        {{true, R1}, T2} ->
+            grab(T2, R, ["</blockquote>",
+                         make_escape_string(R1, R),
+                         "<blockquote>" | Acc], W);
+        {{esc_false, R1}, _T2} ->
+            {R1, lists:reverse(Acc), false};
+        {false, T2} ->
+            case is_double_indent(S) of
+                false ->
+                    {List, lists:reverse(Acc), false};
+                {true, R2} ->
+                    %% if it is a double indent - delete 4 spaces
+                    %% no it makes not sense to me neither :(
+                    grab(T2, R, ["    " ++ make_escape_string(R2, R) | Acc], W)
+            end
+    end;
+grab([{linefeed, _} | T], R, Acc, false) ->
+    grab2(T, R, Acc, T, Acc, true);
+grab([{linefeed, _} | T], R, Acc, true) ->
+    grab2(T, R, ["\n" | Acc], T, Acc, true);
+grab([{blank, _} | T], R, Acc, false) ->
+    grab2(T, R, Acc, T, Acc, true);
+grab([{blank, _} | T], R, Acc, true) ->
+    grab2(T, R, ["\n" | Acc], T, Acc, true);
+grab([{normal, P} | T], R, Acc, W) ->
+    Li = case W of
+             false ->
+                 make_escape_string(P, R);
+             true  ->
+                 "<p>"++ string:strip(make_escape_string(P, R), right, ?LF)
+                     ++ "</p>"
+         end,
+    grab(T, R, [Li | Acc], W);
+grab(List, _R, Acc, W) ->
+    {List, lists:reverse(Acc), W}.
+
+%% the problem is knowing when to grab, if the list is followed by a long
+%% string of blank lines and linefeeds and a normal then the linefeeds aren't
+%% grabbed
+%% if the list if followed by blank lines and linefeeds and a normal with an
+%% initial whitespace it is grabbed...
+grab2([{normal, P2} | T], R, Acc, LO, AO, W) ->
+    case P2 of
+        [{{ws, _}, _} | T2] ->
+            Li = case W of
+                     false ->
+                         make_escape_string(T2, R);
+                     true  ->
+                         "<p>" ++
+                             string:strip(make_escape_string(T2, R), right, ?LF)
+                             ++ "</p>"
+                 end,
+            grab(T, R, [Li | Acc], W);
+        _ ->
+            {LO, AO, false}
+    end;
+grab2([{linefeed, _} | T], R, Acc, LO, AO, _W) ->
+    grab2(T, R, ["\n" | Acc], LO, AO, true);
+grab2([{blank, _} | T], R, Acc, LO, AO, _W) ->
+    grab2(T, R, ["\n" | Acc], LO, AO, true);
+%% We dont want to grab this stuff so return the old list and the old acc
+grab2(_List, _R, _Acc, LO, AO, _W) ->
+    {LO, AO, true}.
+
+is_double_indent(List) ->
+    is_double_indent1(List, 0).
+
+%% double indent is any combination of tabs and spaces that add
+%% up to 8
+is_double_indent1([], _N) ->
+    false;
+is_double_indent1(Rest, N)
+  when N > 7 ->
+    {true, Rest};
+is_double_indent1([{{ws, sp}, _} | T], N)  ->
+    is_double_indent1(T, N + 1);
+is_double_indent1([{{ws, tab}, _} | T], N) ->
+    is_double_indent1(T, N + 4);
+is_double_indent1(_List, _N) ->
+    false.
+
+is_blockquote(List, T) ->
+    case is_bq1(List, 0) of
+        false ->
+            {false, T};
+        {esc_false, R} ->
+            {{esc_false, R}, T};
+        {true, R} ->
+            {NewT, NewR} = grab2(T, R),
+            {{true, NewR}, NewT}
+    end.
+
+is_bq1([], _N) ->
+    false;
+is_bq1([{{ws, sp}, _} | T], N) ->
+    is_bq1(T, N + 1);
+is_bq1([{{ws, tab}, _} | T], N) ->
+    is_bq1(T, N + 4);
+is_bq1([{{md, gt}, _}, {{ws, _}, _} | T], N)
+  when N > 3  ->
+    {true, T};
+is_bq1([{{punc, bslash}, _}, {{md, gt}, GT}, {{ws, _}, WS} | T], N)
+  when N > 3 ->
+    {esc_false, [GT, WS | T]};
+is_bq1(_List, _N) ->
+    false.
+
+grab2(List, R) ->
+    gb2(List, lists:reverse(R)).
+
+gb2([], Acc) ->
+    {[], lists:flatten(lists:reverse(Acc))};
+gb2([{blank, _} | T], Acc) ->
+    {T, lists:flatten(lists:reverse(Acc))};
+gb2([{_Type, P} | T], Acc) ->
+    gb2(T, [P | Acc]).
+
+%%
+%% Make the lines from the raw tokens
+%%
+make_lines(Tokens) ->
+    ml1(Tokens, [], []).
+
+ml1([], [], A2) ->
+    lists:reverse(A2);
+ml1([], A1, A2) ->
+    ml1([], [], [lists:reverse(A1) | A2]);
+ml1([{{lf, _}, _} = H | T], A1, A2) ->
+    ml1(T, [], [ml2(H, A1) | A2]);
+ml1([H | T], A1, A2) ->
+    ml1(T, [H | A1], A2).
+
+ml2(H, List) ->
+    lists:reverse([H | List]).
+
+%%%
+%%% Process the lines and give each line a type. The valid types are:
+%%% * normal line
+%%% * reference style links
+%%% * reference style images
+%%% * special line types
+%%%   - blank
+%%%   - SETEXT header lines
+%%%   - ATX header lines
+%%%   - unordered lists (including code blocks)
+%%%   - ordered lists (including code blocks)
+%%%   - blockquotes
+%%%   - code blocks
+%%%   - horizontal rules
+%%%
+type_lines(Lines) ->
+    {Refs, TypedLines} = type_lines1(Lines, [], []),
+    {strip_lines(TypedLines), Refs}.
+
+type_lines1([], A1, A2) ->
+    {A1, lists:reverse(A2)};
+type_lines1([[{{ws, sp}, _}, {{inline, open}, _} | T1] = H | T2], A1, A2) ->
+    %% this clause extracts URL and Image refs
+    %% (it is the only one that uses A1 and A2...
+    %% inlines can have up to 3 spaces before it
+    t_inline(H, T1, T2, A1, A2);
+type_lines1([[{{ws, tab}, _}, {{inline, open}, _} | T1] = H | T2], A1, A2) ->
+    t_inline(H, T1, T2, A1, A2);
+type_lines1([[{{ws, comp}, W}, {{inline, open}, _} | T1] = H | T2], A1, A2) ->
+    case gt(W, 3) of
+        {true, _R} ->
+            t_inline(H, T1, T2, A1, A2);
+        false      ->
+            type_lines1(T1, A1, [{normal , H} | A2]) % same exit at the final clause!
+    end,
+    t_inline(H, T1, T2, A1, A2);
+type_lines1([[{{inline, open}, _} | T1] = H | T2], A1, A2) ->
+    t_inline(H, T1, T2, A1, A2);
+type_lines1([[{{md, eq}, _} | _T] = H | T], A1, A2) ->
+    %% types setext lines
+    type_lines1(T, A1, [type_setext_h1(H) | A2]);
+type_lines1([[{{md, dash}, _} | _T] = H | T], A1, A2) ->
+    %% NOTE 1: generates a ul as the default not a normal line
+    %% NOTE 2: depending on the context this might generate an <h2> header
+    %%         or an <hr />
+    %% NOTE 3: space - is typed to a bullet down in <ul> land...
+    type_lines1(T, A1, [type_setext_h2(H) | A2]);
+type_lines1([[{{md, atx}, _} | _T] = H | T], A1, A2) ->
+    %% types atx lines
+    type_lines1(T, A1, [type_atx(H) | A2]);
+type_lines1([[{{md, gt}, _} | []] = H | T], A1, A2) ->
+    %% types blockquotes
+    %% a blockquote on its own or followed by a linefeed is
+    %% displayed 'as is' by showdown
+    type_lines1(T, A1, [{normal, H} | A2]);
+type_lines1([[{{md, gt}, _}, {{lf, _}, _} | []] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{normal, H} | A2]);
+%% one with anything after it starts a blockquote
+type_lines1([[{{md, gt}, _} | _T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{blockquote, H} | A2]);
+type_lines1([[{{ws, _}, _}, {{md, star}, _} = ST1, {{ws, _}, _} = WS1 | T1] = H | T], A1, A2) ->
+    %% types unordered lists lines
+    %% NOTE 1: the dashed version is generated in type_setext_h2
+    %% NOTE 2: the asterix version also might generate a horizontal rule
+    %%         which is why it jumps to type_star2 <-- note the 2!!
+    type_lines1(T, A1, [{type_star2([ST1, WS1 | T1]), H} | A2]);
+type_lines1([[{{md, star}, _}, {{ws, _}, _} | _T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{type_star2(H), H} | A2]);
+type_lines1([[{{ws, _}, _}, {{md, plus}, _}, {{ws, _}, _} = W | T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{{ul, make_list_str([W | T1])}, H} | A2]);
+type_lines1([[{{md, plus}, _}, {{ws, _}, _} = W | T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{{ul, make_list_str([W | T1])}, H} | A2]);
+%% UL based on dashes
+type_lines1([[{{ws, _}, _}, {{md, dash}, _}, {{ws, _}, _} = W | T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [{{ul, make_list_str([W | T1])}, H} | A2]);
+type_lines1([[{{ws, _}, _}, {num, _} = N1| T1] | T], A1, A2) ->
+    %% types ordered lists...
+    type_lines1(T, A1, [type_ol([N1 | T1]) | A2]);
+type_lines1([[{num, _} | _T] = H | T], A1, A2) ->
+    type_lines1(T, A1, [type_ol(H) | A2]);
+type_lines1([[{{md, underscore}, _} | _T1] = H | T], A1, A2) ->
+    %% types horizontal rules for stars and underscores
+    %% dashes and some stars are done elsewhere...
+    type_lines1(T, A1, [type_underscore(H) | A2]);
+type_lines1([[{{md, star}, _} | _T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [type_star(H) | A2]);
+type_lines1([[{{{tag, _Type}, Tag}, _ } = H | T1] = List | T], A1, A2) ->
+    %% Block level tags - these are look ahead they must be
+    %% on a single line (ie directly followed by a lf and nothing else
+    case is_blank(T1) of
+        false ->
+            type_lines1(T, A1, [{normal , List} | A2]);
+        true  ->
+            case is_block_tag(Tag) of
+                true  ->
+                    type_lines1(T, A1, [{blocktag , [H]} | A2]);
+                false ->
+                    type_lines1(T, A1, [{tag, [H | T1]} | A2])
+            end
+    end;
+type_lines1([[{{lf, _}, _}| []]  = H | T], A1, A2) ->
+    %% types a blank line or a code block
+    type_lines1(T, A1, [{linefeed, H} | A2]);
+type_lines1([[{{ws, _}, _} | _T1] = H | T], A1, A2) ->
+    type_lines1(T, A1, [type_ws(H) | A2]);
+
+%% Final clause...
+type_lines1([H | T], A1, A2) ->
+    type_lines1(T, A1, [{normal , H} | A2]).
+
+t_inline(H, T1, T2, A1, A2) ->
+    case snip_ref(T1) of
+        {Type, {Id, {Url, Title}}} ->
+            type_lines1(T2, lists:flatten([{Id, {Url, Title}} | A1]),
+                        [{Type, H} | A2]);
+        normal ->
+            type_lines1(T2, A1, [{normal, H} | A2])
+    end.
+
+%% strips blanks from the beginning and end
+strip_lines(List) ->
+    lists:reverse(strip_lines1(lists:reverse(strip_lines1(List)))).
+
+strip_lines1([{linefeed, _} | T]) ->
+    strip_lines1(T);
+strip_lines1([{blank, _} | T]) ->
+    strip_lines1(T);
+strip_lines1(List)  ->
+    List.
+
+%%
+%% Loads of type rules...
+%%
+is_blank([]) ->
+    true;
+is_blank([{{lf, _}, _} | []]) ->
+    true;
+is_blank([{{ws, _}, _} | T])  ->
+    is_blank(T);
+is_blank(_List) ->
+    false.
+
+is_block_tag("address") ->
+    true;
+is_block_tag("blockquote") ->
+    true;
+is_block_tag("center") ->
+    true;
+is_block_tag("dir") ->
+    true;
+is_block_tag("div") ->
+    true;
+is_block_tag("dl") ->
+    true;
+is_block_tag("fieldset") ->
+    true;
+is_block_tag("form") ->
+    true;
+is_block_tag("h1") ->
+    true;
+is_block_tag("h2") ->
+    true;
+is_block_tag("h3") ->
+    true;
+is_block_tag("h4") ->
+    true;
+is_block_tag("h5") ->
+    true;
+is_block_tag("h6") ->
+    true;
+is_block_tag("hr") ->
+    true;
+is_block_tag("isindex") ->
+    true;
+is_block_tag("menu") ->
+    true;
+is_block_tag("noframes") ->
+    true;
+is_block_tag("noscript") ->
+    true;
+is_block_tag("ol") ->
+    true;
+is_block_tag("p") ->
+    true;
+is_block_tag("pre") ->
+    true;
+is_block_tag("table") ->
+    true;
+is_block_tag("thead") ->
+    true;
+is_block_tag("tbody") ->
+    true;
+is_block_tag("tr") ->
+    true;
+is_block_tag("td") ->
+    true;
+is_block_tag("ul") ->
+    true;
+is_block_tag(_Other) ->
+    false.
+
+type_underscore(List) ->
+    case type_underscore1(trim_right(List)) of
+        hr ->
+            {hr, List};
+        maybe ->
+            {type_underscore2(List), List}
+    end.
+
+type_underscore1([]) ->
+    hr;
+type_underscore1([{{md, underscore}, _} | T]) ->
+    type_underscore1(T);
+type_underscore1(_List) ->
+    maybe.
+
+type_underscore2(List) ->
+    case trim_right(List) of % be permissive of trailing spaces
+        [{{md, underscore}, _}, {{ws, _}, _},
+         {{md, underscore}, _}, {{ws, _}, _},
+         {{md, underscore}, _}] ->
+            hr;
+        _Other ->
+            normal
+    end.
+
+type_star(List) ->
+    Trim = trim_right(List),
+    case type_star1(Trim) of % be permssive of trailing spaces
+        hr ->
+            {hr, trim_right(Trim)};
+        maybe ->
+            Type = type_star2(List),
+            %% if it is a normal line we prepend it with a special
+            %% non-space filling white space character
+            case Type of
+                normal ->
+                    {normal, [{{ws, none}, none} | List]};
+                _ ->
+                    {Type, List}
+            end
+    end.
+
+type_star1([]) ->
+    hr;
+type_star1([{{md, star}, _} | T]) ->
+    type_star1(T);
+type_star1(_List) ->
+    maybe.
+
+type_star2(List) ->
+    case trim_right(List) of
+        [{{md, star}, _}, {{ws, _}, _},
+         {{md, star}, _}, {{ws, _}, _},
+         {{md, star}, _}] ->
+            hr;
+        _Other ->
+            case List of
+                [{{md, star}, _},
+                 {{ws, _}, _}= WS | T] ->
+                    {ul, make_list_str([WS | T])};
+                _Other2  ->
+                    normal
+            end
+    end.
+
+type_ol(List) ->
+    case type_ol1(List, []) of
+        normal ->
+            {normal, List};
+        {ol, Str} ->
+            {{ol, Str}, List};
+        {esc_normal, Str} ->
+            {normal, Str}
+    end.
+
+%% this line terminates on an escaped fullstop after a number
+%% (but you need to drop the bslash...)
+type_ol1([{num, _} = N,
+          {{punc, bslash}, _},
+          {{punc, fullstop}, _} = P | T], Acc) ->
+    {esc_normal, lists:flatten([lists:reverse(Acc), N, P | T])};
+type_ol1([{num, _} = H | T], Acc)  ->
+    %% we accumulate the digits in case we need to escape a full stop in a normal line
+    type_ol1(T, [H | Acc]);
+type_ol1([{{punc, fullstop}, _}, {{ws, _}, _} | T], _Acc) ->
+    {ol, T};
+type_ol1(_List, _Acc) ->
+    normal.
+
+%% You need to understand what this function is trying to d...
+%% '### blah' is fine
+%% '### blah ###' is reduced to '### blah' because trailing #'s are
+%% just for show but...
+%% '##' is like appling '#' to '#' <-- applying 1 less styling to a single #
+%% and '###' is like appling '##' to '#' etc, etc
+%% but after you hit 6#'s you just get this for a single hash
+%% ie '#############' is like applying '######' to a single '#'
+%% but/and '######## blah' is like apply '######' to '## blah'
+%% strip trailing #'s as they are decorative only...
+type_atx(List) ->
+    {Sz, R} = get_atx_size(List),
+    A = [{{md, atx}, "#"}],
+    Type =
+        case is_all_hashes(R) of
+            true  ->
+                if
+                    Sz == 1 ->
+                        normal;
+                    ((Sz > 1) andalso (Sz < 6)) ->
+                        Ns = integer_to_list(Sz - 1),
+                        Hn = list_to_atom("h" ++ Ns),
+                        {Hn, A};
+                    ((Sz == 6) andalso (R == [])) ->
+                        {h5, A};
+                    ((Sz == 6) andalso (R == [{{lf, lf}, "\n"}])) ->
+                        {h5, A};
+                    ((Sz == 6) andalso (R == [{{lf, crlf}, "\r\n"}])) ->
+                        {h5, A};
+                    ((Sz == 6) andalso (R =/= [])) ->
+                        {h6, A}
+                end;
+            false ->
+                Ns = integer_to_list(Sz),
+                Hn = list_to_atom("h" ++ Ns),
+                {Hn, strip_atx(R)}
+        end,
+    {Type, List}.
+
+is_all_hashes([]) ->
+    true;
+is_all_hashes([{{md, atx}, _} | T]) ->
+    is_all_hashes(T);
+is_all_hashes([{{lf, _}, _} | []])  ->
+    true;
+is_all_hashes(_List) ->
+    false.
+
+get_atx_size(List) ->
+    g_atx_size1(List, 0).
+
+                                                % this function also strips whitespace to the left...
+g_atx_size1([{{md, atx}, _} = A | T], N) when N == 6 ->
+    {6, [A | T]};
+g_atx_size1([{{md, atx}, _} | T], N) ->
+    g_atx_size1(T, N + 1);
+g_atx_size1([{{ws, _}, _} | T], N) ->
+    g_atx_size1(T, N);
+g_atx_size1(List, N) ->
+    {N, List}.
+
+strip_atx(List) ->
+    lists:reverse(s_atx1(lists:reverse(List))).
+
+s_atx1([{{lf, _}, _}, {{md, atx}, _} | T]) ->
+    s_atx1(T);
+s_atx1([{{md, atx}, _} | T])  ->
+    s_atx1(T);
+s_atx1(List) ->
+    List.
+
+type_setext_h1(List) ->
+    type_s_h1_1(List, []).
+
+%% terminates on running out or new line
+type_s_h1_1([{{lf, _}, _} = L | []], Acc) ->
+    {setext_h1, lists:reverse([L | Acc])};
+type_s_h1_1([], Acc)->
+    {setext_h1, lists:reverse(Acc)};
+type_s_h1_1([[] | T], Acc) ->
+    type_s_h1_1(T, Acc);
+type_s_h1_1([{{md, eq}, _} = H | T], Acc) ->
+    type_s_h1_1(T, [H | Acc]);
+type_s_h1_1(L, Acc) ->
+    {normal, lists:flatten([Acc | L])}.
+
+type_setext_h2(List) ->
+    case type_s_h2_1(List) of
+        h2_or_hr ->
+            {h2_or_hr, List};
+        not_h2 ->
+            {type_s_h2_2(trim_right(List)), List}
+    end.
+%% terminates on running out or new line
+type_s_h2_1([{{lf, _}, _} | []])   ->
+    h2_or_hr;
+type_s_h2_1([]) ->
+    h2_or_hr;
+type_s_h2_1([[] | T]) ->
+    type_s_h2_1(T);
+type_s_h2_1([{{md, dash}, _} | T]) ->
+    type_s_h2_1(T);
+type_s_h2_1(_L) ->
+    not_h2.
+
+type_s_h2_2([{{md, dash}, _}, {{ws,_}, _},
+             {{md, dash}, _}, {{ws, _}, _},
+             {{md, dash}, _}]) ->
+    hr;
+type_s_h2_2([{{md, dash}, _},
+             {{ws, _}, _} = WS | T]) ->
+    {ul, make_list_str([WS | T])};
+type_s_h2_2(_List) ->
+    normal.
+
+type_ws(List) ->
+    case type_ws1(List) of
+        blank ->
+            {blank, List};
+        try_codeblock ->
+            case type_ws2(List) of
+                normal ->
+                    {normal, List};
+                {codeblock, Ret} ->
+                    {{codeblock, Ret}, List}
+            end
+    end.
+
+type_ws1([]) ->
+    blank;
+type_ws1([{{lf, _}, _} | []]) ->
+    blank;
+type_ws1([[] | T]) ->
+    type_ws1(T);
+type_ws1([{{ws, _}, _} | T])  ->
+    type_ws1(T);
+type_ws1(_L) ->
+    try_codeblock.
+
+%% 4 or more spaces takes you over the limit
+%% (a tab is 4...)
+type_ws2([{{ws, tab}, _} | T])  ->
+    {codeblock, T};
+type_ws2([{{ws, comp}, W} | T]) ->
+    case gt(W, 4) of
+        {true, R} ->
+            {codeblock, [R| T]};
+        false ->
+            normal
+    end;
+type_ws2([{{ws, sp}, _} | _T])  ->
+    normal.
+
+gt(String, Len) ->
+    ExpString = re:replace(String, "\t", "    ", [{return, list}]),
+    ExpStringLen = length(ExpString),
+    if
+        ExpStringLen >= Len ->
+            WS = string:substr(ExpString, Len + 1,
+                               ExpStringLen),
+            {true, {{ws, sp}, WS}};
+        ExpStringLen <  Len ->
+            false
+    end.
+
+%% make a tag into a string
+make_tag_str(L, R) ->
+    make_tag1(L, R, []).
+
+make_tag1([], _R, Acc) ->
+    lists:reverse(Acc);
+make_tag1([{{{tag, _Type}, _Tag}, B} | T], R, Acc) ->
+    make_tag1(T, R, [B | Acc]);
+make_tag1([H | T], R, Acc) ->
+    make_tag1(T, R, [make_string([H], R) | Acc]).
+
+esc_tag(String) ->
+    esc_tag1(String, []).
+
+esc_tag1([], Acc) ->
+    lists:reverse(Acc);
+esc_tag1([?NBSP | T], Acc) ->
+    esc_tag1(T, [?SPACE | Acc]); % non-breaking space to space
+esc_tag1([H | T], Acc) ->
+    esc_tag1(T, [H | Acc]).
+
+%% if it is a list we need to discard the initial white space...
+make_list_str([{{ws, _}, _} | T] = List) ->
+    case is_double_indent(List) of
+        false ->
+            T;
+        {true, R} ->
+            lists:flatten([{tags, "<pre><code>"} ,R ,
+                           {tags, "</code></pre>\n\n"} | []])
+    end.
+
+%% All ref processing can ignore the original values 'cos those
+%% have already been captured at a higher level
+snip_ref(List) ->
+    case get_id(List) of
+        {[{_, Id}], Rest} ->
+            {_Rest2, Ref, Title} = parse_inline(Rest),
+            Ref2 = trim(Ref),
+            Rs = htmlencode(make_plain_string(Ref2)),
+            Ts = make_plain_string(Title),
+            {inlineref, {Id, {Rs, Ts}}};
+        normal ->
+            normal
+    end.
+
+get_id(List) ->
+    g_id1(List, []).
+
+g_id1([], _Acc) ->
+    normal;
+g_id1([{{inline, close}, _}, {{punc, colon}, _}, {{ws, _}, _} | T], Acc) ->
+    {lists:reverse(Acc), T};
+g_id1([H | T], Acc) ->
+    g_id1(T, [H | Acc]).
+
+parse_inline(List) ->
+    parse_inline1(List, []).
+
+%% snip off the terminal linefeed (if there is one...)
+parse_inline1([{{lf, _}, _} | []], A) ->
+    {[], lists:reverse(A), []};
+parse_inline1([], A) ->
+    {[], lists:reverse(A), []};
+parse_inline1([{{punc, bslash}, _}, {bra, _} = B | T], A) ->
+    %% brackets can be escaped
+    parse_inline1(T, [B | A]);
+parse_inline1([{{punc, bslash}, _}, {ket, _} = B | T], A) ->
+    parse_inline1(T, [B | A]);
+parse_inline1([{{punc, bslash}, _}, {{punc, doubleq}, _} = Q | T], A) ->
+    parse_inline1(T, [Q | A]);
+parse_inline1([{{punc, bslash}, _}, {{punc, singleq}, _} = Q | T], A) ->
+    parse_inline1(T, [Q | A]);
+parse_inline1([{{punc, doubleq}, _} | T], A) ->
+    %% these clauses capture the start of the title...
+    parse_inline2(T, lists:reverse(A), doubleq, []);
+parse_inline1([{{punc, singleq}, _} | T], A) ->
+    parse_inline2(T, lists:reverse(A), singleq, []);
+parse_inline1([{bra, _} | T], A) ->
+    parse_inline2(T, lists:reverse(A), brackets, []);
+parse_inline1([{ket, _} | T], A) ->
+    {T, lists:reverse(A), []};
+parse_inline1([H | T], A) ->
+    parse_inline1(T, [H | A]).
+
+%% this gets titles in single and double quotes
+%% the delimiter type is passed in as 'D'
+parse_inline2([], Url, _D, A) ->
+    {[], Url, lists:flatten(lists:reverse(A))};
+
+parse_inline2([{{punc, bslash}, _}, {bra, _} = B | T], Url, D, A) ->
+    %% brackets can be escaped
+    parse_inline2(T, Url, D, [B | A]);
+parse_inline2([{{punc, bslash}, _}, {ket, _} = B | T], Url, D, A) ->
+    parse_inline2(T, Url, D, [B | A]);
+parse_inline2([{{punc, bslash}, _},
+               {{punc, doubleq}, _}= Q | T], Url, D, A)    ->
+    %% quotes can be escaped
+    parse_inline2(T, Url, D, [Q | A]);
+parse_inline2([{{punc, bslash}, _}, {{punc, singleq}, _} = Q | T], Url, D, A) ->
+    parse_inline2(T, Url, D, [Q | A]);
+parse_inline2([{{punc, doubleq}, _} | T], Url, doubleq, A) ->
+    %% these clauses capture the end of the title and drop the delimiter...
+    parse_inline2(T, Url, none, A);
+parse_inline2([{{punc, singleq}, _} | T], Url, singleq, A) ->
+    parse_inline2(T, Url, none, A);
+parse_inline2([{ket, _} | T], Url, brackets, A) ->
+    parse_inline2(T, Url, none, A);
+parse_inline2([{ket, _} | T], Url, none, A) ->
+    %% terminator clause
+    {T, Url, lists:flatten(lists:reverse(A))};
+parse_inline2([_H | T], Url, none, A) ->
+    %% this clause silently discards stuff after the delimiter...
+    parse_inline2(T, Url, none, [A]);
+parse_inline2([H | T], Url, D, A) ->
+    parse_inline2(T, Url, D, [H | A]).
+
+trim(String) ->
+    trim_left(trim_right(String)).
+
+trim_right(String) ->
+    lists:reverse(trim_left(lists:reverse(String))).
+
+trim_left([{{ws, _}, _} | T]) ->
+    trim_left(T);
+trim_left([[] | T]) ->
+    trim_left(T);
+trim_left(List) ->
+    List.
+
+snip(List) ->
+    List2 = lists:reverse(List),
+    case List2 of
+        [{{lf, _}, _} | T] ->
+            lists:reverse(T);
+        _  ->
+            List
+    end.
+
+%% end of ref processing
+
+%%
+%% Build the Lexed Token List
+%% This is a two part lexer, first it chunks the input and then on the second
+%% pass it gathers it into lines and types the lines
+%%
+%% NOTE that there are two different styles of processing lines:
+%% * markdown transformed
+%% * block
+%% inside block processing the whole text is dumped and just url encoded
+%% and the original text is always maintained during the lexing/parsing
+%% so that it can be recreated if the context requires it...
+%%
+
+lex(String) ->
+    merge_ws(lex1(String, [], [])).
+
+merge_ws(List) ->
+    merge_ws1(List, []).
+
+merge_ws1([], Acc) ->
+    lists:reverse(Acc);
+merge_ws1([{{ws, _}, W1}, {{ws, _}, W2} | T], Acc) ->
+    merge_ws1([{{ws, comp}, W1 ++ W2} | T], Acc);
+merge_ws1([H | T], Acc) ->
+    merge_ws1(T, [H | Acc]).
+
+%% this is the terminal head which ends the parsing...
+lex1([], [], A2) ->
+    lists:flatten(lists:reverse(A2));
+lex1([], A1, A2) ->
+    lex1([], [], [lex2(A1) | A2]);
+%% these two heads capture opening and closing tags
+lex1([$<, $/|T], A1, A2) ->
+    {Tag, NewT} = closingdiv(T, []),
+    lex1(NewT, [], [Tag, lex2(A1) | A2]);
+lex1([$< | T], A1, A2) ->
+    {Tag, NewT} = openingdiv(T),
+    lex1(NewT, [], [Tag , lex2(A1) | A2]);
+%% these clauses are the normal lexer clauses
+lex1([$= | T], A1, A2) ->
+    lex1(T, [], [{{md, eq}, "="},  lex2(A1) | A2]);
+lex1([$- | T], A1, A2) ->
+    lex1(T, [], [{{md, dash}, "-"}, lex2(A1) | A2]);
+lex1([$# | T], A1, A2) ->
+    lex1(T, [], [{{md, atx}, "#"},  lex2(A1) | A2]);
+lex1([$> | T], A1, A2) ->
+    lex1(T, [], [{{md, gt}, ">"},   lex2(A1) | A2]);
+lex1([$+ | T], A1, A2) ->
+    lex1(T, [], [{{md, plus}, "+"}, lex2(A1) | A2]);
+lex1([$* | T], A1, A2) ->
+    lex1(T, [], [{{md, star}, "*"}, lex2(A1) | A2]);
+lex1([$_ | T], A1, A2) ->
+    lex1(T, [], [{{md, underscore}, "_"}, lex2(A1) | A2]);
+lex1([$1 | T], A1, A2) ->
+    lex1(T, [], [{num, "1"}, lex2(A1) | A2]);
+lex1([$2 | T], A1, A2) ->
+    lex1(T, [], [{num, "2"}, lex2(A1) | A2]);
+lex1([$3 | T], A1, A2) ->
+    lex1(T, [], [{num, "3"}, lex2(A1) | A2]);
+lex1([$4 | T], A1, A2) ->
+    lex1(T, [], [{num, "4"}, lex2(A1) | A2]);
+lex1([$5 | T], A1, A2) ->
+    lex1(T, [], [{num, "5"}, lex2(A1) | A2]);
+lex1([$6 | T], A1, A2) ->
+    lex1(T, [], [{num, "6"}, lex2(A1) | A2]);
+lex1([$7 | T], A1, A2) ->
+    lex1(T, [], [{num, "7"}, lex2(A1) | A2]);
+lex1([$8 | T], A1, A2) ->
+    lex1(T, [], [{num, "8"}, lex2(A1) | A2]);
+lex1([$9 | T], A1, A2) ->
+    lex1(T, [], [{num, "9"}, lex2(A1) | A2]);
+lex1([$0 | T], A1, A2) ->
+    lex1(T, [], [{num, "0"}, lex2(A1) | A2]);
+lex1([$. | T], A1, A2) ->
+    lex1(T, [], [{{punc, fullstop}, "."}, lex2(A1) | A2]);
+lex1([$: | T], A1, A2) ->
+    lex1(T, [], [{{punc, colon}, ":"}, lex2(A1) | A2]);
+lex1([$' | T], A1, A2) ->
+    lex1(T, [], [{{punc, singleq}, "'"}, lex2(A1) | A2]); %'
+lex1([$" | T], A1, A2) ->
+    lex1(T, [], [{{punc, doubleq}, "\""}, lex2(A1) | A2]); %"
+lex1([$` | T], A1, A2) ->
+    lex1(T, [], [{{punc, backtick}, "`"}, lex2(A1) | A2]); %"
+lex1([$! | T], A1, A2) ->
+    lex1(T, [], [{{punc, bang}, "!"}, lex2(A1) | A2]); %"
+lex1([$\\ | T], A1, A2)->
+    lex1(T, [], [{{punc, bslash}, "\\"}, lex2(A1) | A2]); %"
+lex1([$/ | T], A1, A2) ->
+    lex1(T, [], [{{punc, fslash}, "/"}, lex2(A1) | A2]); %"
+lex1([$( | T], A1, A2) ->
+    lex1(T, [], [{bra, "("}, lex2(A1) | A2]);
+lex1([$) | T], A1, A2) ->
+    lex1(T, [], [{ket, ")"}, lex2(A1) | A2]);
+lex1([$[ | T], A1, A2) ->
+    lex1(T, [], [{{inline, open}, "["}, lex2(A1) | A2]);
+lex1([$] | T], A1, A2) ->
+    lex1(T, [], [{{inline, close}, "]"}, lex2(A1) | A2]);
+lex1([?SPACE | T], A1, A2) ->
+    %% note there is a special 'whitespace' {{ws, none}, ""} which is used to generate non-space
+    %% filling whitespace for cases like '*bob* is great' which needs a non-space filling
+    %% whitespace prepended to trigger emphasis so it renders as "<em>bob</em> is great...
+    %% that 'character' doesn't exist so isn't in the lexer but appears in the parser
+    lex1(T, [], [{{ws, sp}, " "}, lex2(A1) | A2]);
+lex1([?TAB | T], A1, A2) ->
+    lex1(T, [], [{{ws, tab}, "\t"}, lex2(A1) | A2]);
+lex1([?NBSP | T], A1, A2) ->
+    lex1(T, [], [{{ws, sp}, "&nbsp"}, lex2(A1) | A2]);
+lex1([?CR, ?LF | T], A1, A2) ->
+    lex1(T, [], [{{lf, crlf}, [?CR , ?LF]}, lex2(A1) | A2]);
+lex1([?LF | T], A1, A2) ->
+    lex1(T, [], [{{lf, lf}, [?LF]}, lex2(A1) | A2]);
+lex1([H|T], A1, A2) ->
+    %% this final clause accumulates line fragments
+    lex1(T, [H |A1] , A2).
+
+lex2([]) ->
+    [];
+lex2(List) ->
+    {string, lists:flatten(lists:reverse(List))}.
+
+%% need to put in regexes for urls and e-mail addies
+openingdiv(String) ->
+    case get_url(String) of
+        {{url, URL}, R1} ->
+            {{url, URL}, R1};
+        not_url ->
+            case get_email_addie(String) of
+                {{email, EM}, R2} ->
+                    {{email, EM}, R2};
+                not_email ->
+                    openingdiv1(String, [])
+            end
+    end.
+
+                                                % dumps out a list if it is not an opening div
+openingdiv1([], Acc) ->
+    {lists:flatten([{{punc, bra}, "<"} | lex(lists:reverse(Acc))]), []};
+openingdiv1([$/,$>| T], Acc) ->
+    Acc2 = lists:flatten(lists:reverse(Acc)),
+    Acc3 = string:to_lower(Acc2),
+    [Tag | _T] = string:tokens(Acc3, " "),
+    {{{{tag, self_closing}, Tag}, "<"
+      ++ Acc2 ++ "/>"}, T};
+openingdiv1([$>| T], []) ->
+    %% special for non-tags
+    {[{{punc, bra}, "<"},
+      {{punc, ket}, ">"}], T};
+openingdiv1([$>| T], Acc) ->
+    Acc2 = lists:flatten(lists:reverse(Acc)),
+    Acc3 = string:to_lower(Acc2),
+    [Tag | _T] = string:tokens(Acc3, " "),
+    {{{{tag, open}, Tag}, "<"
+      ++ Acc2 ++ ">"}, T};
+openingdiv1([H|T], Acc) ->
+    openingdiv1(T, [H | Acc]).
+
+                                                % dumps out a list if it is not an closing div
+closingdiv([], Acc) ->
+    {lists:flatten([{{punc, bra}, "<"}, {{punc, fslash}, "/"}
+                    | lex(lists:reverse(Acc))]), []};
+closingdiv([$>| T], Acc) ->
+    Acc2 = lists:flatten(lists:reverse(Acc)),
+    Acc3 = string:to_lower(Acc2),
+    [Tag | _T] = string:tokens(Acc3, " "),
+    {{{{tag, close}, Tag}, "</"
+      ++ Acc2 ++ ">"}, T};
+closingdiv([H|T], Acc) ->
+    closingdiv(T, [H | Acc]).
+
+get_url(String) ->
+    HTTP_regex = "^(H|h)(T|t)(T|t)(P|p)(S|s)*://",
+    case re:run(String, HTTP_regex) of
+        nomatch ->
+            not_url;
+        {match, _} ->
+            get_url1(String, [])
+    end.
+
+get_url1([], Acc) ->
+    URL = lists:flatten(lists:reverse(Acc)),
+    {{url, URL}, []};
+get_url1([$\\, $> | T], Acc) ->
+    %% allow escaped kets
+    get_url1(T, [$>, $\\ | Acc]);
+get_url1([$> | T], Acc) ->
+    URL = lists:flatten(lists:reverse(Acc)),
+    {{url, URL}, T};
+get_url1([H | T], Acc) ->
+    get_url1(T, [H | Acc]).
+
+get_email_addie(String) ->
+    Snip_regex = ">",
+    case re:run(String, Snip_regex) of
+        nomatch ->
+            not_email;
+        {match, [{N, _} | _T]} ->
+            {Possible, [$> | T]} = lists:split(N, String),
+            EMail_regex = "[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+"
+                ++ "(?:\.[a-zA-Z0-9!#$%&'*+/=?^_`{|}~-]+)*"
+                ++ "@(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?\.)+"
+                ++ "(?:[a-zA-Z]{2}|com|org|net|gov|mil"
+                ++ "|biz|info|mobi|name|aero|jobs|museum)",
+            case re:run(Possible, EMail_regex) of
+                nomatch ->
+                    not_email;
+                {match, _} ->
+                    {{email, Possible}, T}
+            end
+    end.
+
+make_plain_string(List) ->
+    make_plain_string(List, []).
+
+make_plain_string([], Acc) ->
+    lists:flatten(lists:reverse(Acc));
+make_plain_string([{{ws, none}, none} | T], Acc) ->
+    make_plain_string(T, [" " | Acc]);
+make_plain_string([{_, Str} | T], Acc) ->
+    make_plain_string(T, [Str | Acc]).
+
+make_escape_string(List, Refs) ->
+    make_escape_string(List, Refs, []).
+
+make_escape_string([], _R, A)  ->
+    lists:flatten(lists:reverse(A));
+make_escape_string([{tags, Tag} | T], R, A) ->
+    make_escape_string(T, R, [{tags, Tag} | A]);
+make_escape_string([H | T], R, A)  ->
+    make_escape_string(T, R, [make_string([H], R) | A]).
+
+
+make_string(List, Refs) ->
+    make_string(List, Refs, []).
+
+make_string([], _R, A) ->
+    Flat = lists:flatten(lists:reverse(A)),
+    htmlchars(Flat);
+make_string([{{punc, bang}, B}, {{inline, open}, O} | T], R, A) ->
+    case get_inline(T, R, [], img) of
+        {Rest, {Url, Title, Acc}} ->
+            Tag = [make_img_tag(Url, Acc, Title)],
+            make_string(Rest, R, [Tag | A]);
+        {Rest, Tag} ->
+            make_string(Rest, R, [Tag, O, B | A])
+    end;
+%% escape inline open's...
+make_string([{{punc, bslash}, _}, {{inline, open}, O} | T], R, A) ->
+    make_string(T, R, [O | A]);
+make_string([{{inline, open}, O} | T], R, A) ->
+    case get_inline(T, R, [], url) of
+        {Rest, {Url, Title, Acc}} ->
+            Tit = case Title of
+                      [] ->
+                          [];
+                      _  ->
+                          " title=\"" ++ Title ++ "\""
+                  end,
+            Tag = [{tags, "<a href=\"" ++ Url ++ "\""
+                    ++ Tit ++ ">"}, Acc,
+                   {tags, "</a>"} | []],
+            make_string(Rest, R, [Tag | A]);
+        {Rest, Tag} ->
+            make_string(Rest, R, [Tag, O | A])
+    end;
+make_string([{email, Addie} | T], R, A) ->
+    make_string(T, R, [{tags, "\" />"}, Addie, {tags, "<a href=\"mailto:"}| A]);
+make_string([{url, Url} | T], R, A) ->
+    make_string(T, R, [ {tags, "</a>"}, Url, {tags, "\">"}, Url,
+                        {tags, "<a href=\""} | A]);
+make_string([{tags, _} = Tag | T], R, A) ->
+    make_string(T, R, [Tag | A]);
+make_string([{{{tag, Type}, Tag}, _} | T], R, A) ->
+    Tag2 = esc_tag(Tag),
+    TagStr = case Type of
+                 open ->
+                     {tags, "&lt;"  ++ Tag2 ++ "&gt;"};
+                 close ->
+                     {tags, "&lt;/" ++ Tag2 ++ "&gt;"};
+                 self_closing ->
+                     {tags, "&lt;"  ++ Tag2 ++ " /&gt;"}
+             end,
+    make_string(T, R, [TagStr | A]);
+make_string([{_, Orig} | T], R, A)  ->
+    make_string(T, R, [Orig | A]).
+
+get_inline([], _R, A, _) ->
+    %% if the inline doesn't terminate its not an inline...
+    {[], make_plain_string(lists:reverse(A))};
+get_inline([{{punc, bang}, _B}, {{inline, open}, _O} | T], R, A, url) ->
+    %% a url can contain an image inline
+    {Rest, {Url, Title, Acc}} = get_inline(T, R, A, img),
+    Tag = make_img_tag(Url, Acc, Title),
+    %% We double tag the tag so that it can get through the lists:flatteners..
+    get_inline(Rest, R, [{tags, Tag} | A], url);
+get_inline([{{inline, close}, _}, {bra, _} | T], _R, A, _) ->
+    {Rest, Url, Title} = parse_inline(T),
+    Tag = {string:strip(make_plain_string(Url)),
+           make_plain_string(Title),
+           make_plain_string(lists:reverse(A))},
+    {Rest, Tag};
+get_inline([{{inline, close}, _}, {{ws, sp}, _}, {bra, _} | T], _R, A, img) ->
+    %% for img's but not url's you need to allow a single space between them
+    %% to be compatible with showdown :(
+    {Rest, Url, Title} = parse_inline(T),
+    Tag = {string:strip(make_plain_string(Url)),
+           make_plain_string(Title),
+           make_plain_string(lists:reverse(A))},
+    {Rest, Tag};
+get_inline([{{inline, close}, _}, {{inline, open}, _} | T], R, A, _) ->
+    %% this clause detects references to images/links...
+    Text = make_plain_string(lists:reverse(A)),
+    case get_id_diff(T) of
+        normal ->
+            {[], make_plain_string(lists:reverse(A))};
+        {[{_, Id}], Rest} ->
+            {Url, Title} = case lists:keyfind(Id, 1, R) of
+                               false ->
+                                   {"", ""};
+                               {Id, {U, Tit}} ->
+                                   {U, Tit}
+                           end,
+            Tag = {Url, Title, Text},
+            {Rest, Tag};
+        _Other ->
+            {[], make_plain_string(lists:reverse(A))} % random failing id's
+    end;
+get_inline([{{inline, close}, _} = C , {{ws, _}, _},
+            {{inline, open}, _} = O | T], R, A, Type) ->
+    %% so does this one - just delete the space and rethrow it
+    get_inline([C, O | T], R, A, Type);
+get_inline([{{inline, close}, _} | T], R, A, _) ->
+    %% this is the markdown extension clause that takes an id in square brackets without
+    %% any additional stuff as a valid id marker
+    Id = make_plain_string(lists:reverse(A)),
+    case lists:keyfind(Id, 1, R) of
+        false  ->
+            {T, lists:flatten([Id , $]])};
+        {Id, {Url, Title}} ->
+            Tag = {Url, Title, Id},
+            {T, Tag}
+    end;
+get_inline([H | T], R, A, Type) ->
+    get_inline(T, R, [H | A], Type).
+
+get_id_diff(List) ->
+    g_id_diff1(List, []).
+
+g_id_diff1([], _Acc) ->
+    normal;
+g_id_diff1([{{inline, close}, _}| T], Acc) ->
+    {lists:reverse(Acc), T};
+g_id_diff1([H | T], Acc) ->
+    g_id_diff1(T, [H | Acc]).
+
+%% convert ascii into html characters
+htmlencode(List) ->
+    htmlencode(List, []).
+
+htmlencode([], Acc) ->
+    lists:flatten(lists:reverse(Acc));
+
+htmlencode([$& | Rest], Acc) ->
+    htmlencode(Rest, ["&amp;" | Acc]);
+htmlencode([$< | Rest], Acc) ->
+    htmlencode(Rest, ["&lt;" | Acc]);
+htmlencode([$> | Rest], Acc) ->
+    htmlencode(Rest, ["&gt;" | Acc]);
+htmlencode([160 | Rest], Acc) ->
+    htmlencode(Rest, ["&nbsp;" | Acc]);
+htmlencode([Else | Rest], Acc) ->
+    htmlencode(Rest, [Else | Acc]).
+
+htmlchars(List) ->
+    htmlchars1(List, []).
+
+htmlchars1([], Acc) ->
+    lists:flatten(lists:reverse(Acc));
+htmlchars1([{tags, Tag} | T], Acc) ->
+    %% tags are just wheeched out unescaped
+    htmlchars1(T, [Tag | Acc]);
+htmlchars1([?CR, ?LF | T], Acc) ->
+    %% line ends are pushed to a space..
+    htmlchars1(T, ["\n" | Acc]);
+htmlchars1([?LF | T], Acc)  ->
+    %% line ends are pushed to a space..
+    htmlchars1(T, ["\n" | Acc]);
+htmlchars1([?CR | T], Acc)  ->
+    htmlchars1(T, ["\r" | Acc]);
+htmlchars1([$\\, $*, $*, $* | T], A) ->
+    %% there is a non-space filling white space represented by the atom 'none'
+    %% which is created in the parser (NOT IN THE LEXER!) and which triggers
+    %% emphasis or strong tags being turned on...
+    htmlchars1(T, [$*, $*, $* | A]);
+htmlchars1([$*, $*, $* | T], A) ->
+    {T2, NewA} = superstrong(T, $*),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $*, $* | T], A) ->
+    %% repeat for strong
+    htmlchars1(T, [$*, $* | A]);
+htmlchars1([$*, $* | T], A) ->
+    {T2, NewA} = strong(T, $*),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $* | T], A) ->
+    %% likewise for strong
+    htmlchars1(T, [$* | A]);
+htmlchars1([$* | T], A) ->
+    {T2, NewA} = emphasis(T, $*),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $_, $_, $_ | T], A) ->
+    %% and again for underscores
+    htmlchars1(T, [$_, $_, $_ | A]);
+htmlchars1([$_, $_, $_ | T], A) ->
+    %% the none atom is the non-space filling whitespace
+    {T2, NewA} = superstrong(T, $_),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $_, $_ | T], A) ->
+    %% and strong
+    %% and again for underscores
+    htmlchars1(T, [$_, $_ | A]);
+htmlchars1([$_, $_ | T], A) ->
+    {T2, NewA} = strong(T, $_),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $_ | T], A) ->
+    %% likewise for strong
+    htmlchars1(T, [$_ | A]);
+htmlchars1([$_ | T], A) ->
+    {T2, NewA} = emphasis(T, $_),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$\\, $` | T], A) ->
+    %% handle backtick escaping
+    htmlchars1(T, [$` | A]);
+htmlchars1([$`, $` | T], A) ->
+    {T2, NewA} = dblcode(T),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([$` | T], A) ->
+    {T2, NewA} = code(T),
+    htmlchars1(T2, [NewA | A]);
+htmlchars1([?COPY | T], A) ->
+    htmlchars1(T, ["&copy;" | A]);
+htmlchars1([?AMP | T], A)  ->
+    htmlchars1(T, ["&amp;" | A]);
+htmlchars1([$& | T], A) ->
+    htmlchars1(T, ["&amp;" | A]);
+htmlchars1([$< | T], A)  ->
+    htmlchars1(T, ["&lt;" | A]);
+htmlchars1([?NBSP | T], A)  ->
+    htmlchars1(T, ["&nbsp;" | A]);
+htmlchars1([?TAB | T], A) ->
+    htmlchars1(T, ["    " | A]);
+htmlchars1([none | T], A) ->
+    htmlchars1(T, A);
+htmlchars1([H | T], A) ->
+    htmlchars1(T, [H | A]).
+
+emphasis(List, Delim) ->
+    interpolate(List, Delim, "em", "" ,[]).
+strong(List, Delim) ->
+    interpolate2(List, Delim, "strong", "", []).
+superstrong(List, Delim) ->
+    interpolate3(List, Delim, "strong", "em", "", []).
+dblcode(List) ->
+    {T, Tag} = interpolate2(List, $`, "code", "" ,[]),
+    {T, "<pre>" ++ Tag ++ "</pre>"}.
+code(List)  ->
+    interpolateX(List, $`, "code", "", []).
+
+%% pain in the arse - sometimes the closing tag should be preceded by
+%% a "\n" and sometimes not in showdown.js
+%% interpolate is for single delimiters...
+interpolateX([], Delim, _Tag, _X, Acc) ->
+    {[], [Delim] ++ htmlchars(lists:reverse(Acc))};
+interpolateX([Delim | T], Delim, Tag, X, Acc) ->
+    {T,  "<" ++ Tag ++ ">" ++ htmlchars(lists:reverse(Acc)) ++ X ++
+         "</" ++ Tag ++ ">"};
+interpolateX([H | T], Delim, Tag, X, Acc) ->
+    interpolateX(T, Delim, Tag, X, [H | Acc]).
+
+interpolate([], Delim, _Tag, _X, Acc) ->
+    {[], [Delim] ++ htmlchars(lists:reverse(Acc))};
+interpolate([Delim | T], Delim, Tag, X, Acc) ->
+    {T,  "<" ++ Tag ++ ">" ++ htmlchars(lists:reverse(Acc)) ++ X ++
+         "</" ++ Tag ++ ">"};
+interpolate([H | T], Delim, Tag, X, Acc) ->
+    interpolate(T, Delim, Tag, X, [H | Acc]).
+
+%% interpolate two is for double delimiters...
+interpolate2([], Delim, _Tag,  _X, Acc) ->
+    {[], [Delim] ++ [Delim] ++ htmlchars(lists:reverse(Acc))};
+interpolate2([Delim, Delim | T], Delim, Tag, X, Acc) ->
+    {T,  "<" ++ Tag ++ ">" ++ htmlchars(lists:reverse(Acc)) ++ X ++
+         "</" ++ Tag ++ ">"};
+interpolate2([H | T], Delim, Tag, X, Acc) ->
+    interpolate2(T, Delim, Tag, X, [H | Acc]).
+
+%% interpolate three is for double delimiters...
+interpolate3([], D, _Tag1, Tag2, _X, Acc)           ->
+    {[], "<" ++ Tag2 ++ ">" ++ [D] ++ "</" ++ Tag2 ++ ">"
+     ++ htmlchars(lists:reverse(Acc))};
+interpolate3([D, D, D | T], D, Tag1, Tag2, _X, Acc) ->
+    {T,  "<" ++ Tag1 ++ ">" ++  "<" ++ Tag2 ++ ">"
+     ++ htmlchars(lists:reverse(Acc)) ++ "</" ++ Tag2 ++ ">"
+     ++ "</" ++ Tag1 ++ ">"};
+interpolate3([H | T], D, Tag1, Tag2, X, Acc) ->
+    interpolate3(T, D, Tag1, Tag2, X, [H | Acc]).
+
+make_img_tag(Url, Acc, Title) ->
+    {tags, "<img src=\"" ++ Url ++ "\""
+     ++ " alt=\"" ++ Acc ++ "\""
+     ++ " title=\"" ++ Title ++ "\""
+     ++ " />"}.
diff --git a/examples/markdown_middleware/src/markdown_converter.erl b/examples/markdown_middleware/src/markdown_converter.erl
index 24bb132..f380332 100644
--- a/examples/markdown_middleware/src/markdown_converter.erl
+++ b/examples/markdown_middleware/src/markdown_converter.erl
@@ -22,8 +22,8 @@ maybe_generate_markdown(Path) ->
 	end.
 
 resource_path(Path) ->
-	{ok, Cwd} = file:get_cwd(),
-	filename:join([Cwd, "priv", Path]).
+	PrivDir = code:priv_dir(markdown_middleware),
+	filename:join([PrivDir, Path]).
 
 source_path(Path) ->
 	<< (filename:rootname(Path))/binary, ".md" >>.
diff --git a/examples/markdown_middleware/src/markdown_middleware.erl b/examples/markdown_middleware/src/markdown_middleware.erl
deleted file mode 100644
index 6e94350..0000000
--- a/examples/markdown_middleware/src/markdown_middleware.erl
+++ /dev/null
@@ -1,15 +0,0 @@
-%% Feel free to use, reuse and abuse the code in this file.
-
--module(markdown_middleware).
-
-%% API.
--export([start/0]).
-
-%% API.
-
-start() ->
-	ok = application:start(crypto),
-	ok = application:start(cowlib),
-	ok = application:start(ranch),
-	ok = application:start(cowboy),
-	ok = application:start(markdown_middleware).
diff --git a/examples/markdown_middleware/src/markdown_middleware_app.erl b/examples/markdown_middleware/src/markdown_middleware_app.erl
index 75ad886..98a909d 100644
--- a/examples/markdown_middleware/src/markdown_middleware_app.erl
+++ b/examples/markdown_middleware/src/markdown_middleware_app.erl
@@ -15,7 +15,11 @@ start(_Type, _Args) ->
 		{'_', [
 			{"/[...]", cowboy_static, [
 				{directory, {priv_dir, markdown_middleware, []}},
-				{mimetypes, {fun mimetypes:path_to_mimes/2, default}}
+				{mimetypes, [
+					{<<".html">>, [<<"text/html">>]},
+					{<<".mp4">>, [<<"video/mp4">>]},
+					{<<".ogv">>, [<<"video/ogg">>]}
+				]}
 			]}
 		]}
 	]),
diff --git a/examples/markdown_middleware/start.sh b/examples/markdown_middleware/start.sh
deleted file mode 100755
index 6b8549f..0000000
--- a/examples/markdown_middleware/start.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/sh
-erl -pa ebin deps/*/ebin -s markdown_middleware \
-	-eval "io:format(\"Point your browser at http://localhost:8080/video.html~n\")."
-- 
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