built-in markdown crack down on locals; still very slow

ldoc/markdown.lua

@@ -5,7 +5,7 @@
 
 <http://www.frykholm.se/files/markdown.lua>
 
-**Author:** Niklas Frykholm, <niklas@frykholm.se>  
+**Author:** Niklas Frykholm, <niklas@frykholm.se>
 **Date:** 31 May 2008
 
 This is an implementation of the popular text markup language Markdown in pure Lua.
@@ -47,10 +47,10 @@ Permission is hereby granted, free of charge, to any person obtaining a copy of
 software and associated documentation files (the "Software"), to deal in the Software
 without restriction, including without limitation the rights to use, copy, modify, merge,
 publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-to whom the Software is furnished to do so, subject to the following conditions: 
+to whom the Software is furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in all copies
-or substantial portions of the Software. 
+or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
@@ -130,31 +130,33 @@ setfenv(1, M)
 -- Locks table t from changes, writes an error if someone attempts to change the table.
 -- This is useful for detecting variables that have "accidently" been made global. Something
 -- I tend to do all too much.
-function lock(t)
+function M.lock(t)
-	function lock_new_index(t, k, v)
+	local function lock_new_index(t, k, v)
 		error("module has been locked -- " .. k .. " must be declared local", 2)
 	end
 
 	local mt = {__newindex = lock_new_index}
-	if getmetatable(t) then mt.__index = getmetatable(t).__index end
+	if getmetatable(t) then
+      mt.__index = getmetatable(t).__index
+   end
 	setmetatable(t, mt)
 end
 
 -- Returns the result of mapping the values in table t through the function f
-function map(t, f)
+local function map(t, f)
 	local out = {}
 	for k,v in pairs(t) do out[k] = f(v,k) end
 	return out
 end
 
 -- The identity function, useful as a placeholder.
-function identity(text) return text end
+local function identity(text) return text end
 
 -- Functional style if statement. (NOTE: no short circuit evaluation)
-function iff(t, a, b) if t then return a else return b end end
+local function iff(t, a, b) if t then return a else return b end end
 
 -- Splits the text into an array of separate lines.
-function split(text, sep)
+local function split(text, sep)
 	sep = sep or "\n"
 	local lines = {}
 	local pos = 1
@@ -168,7 +170,7 @@ function split(text, sep)
 end
 
 -- Converts tabs to spaces
-function detab(text)
+local function detab(text)
 	local tab_width = 4
 	local function rep(match)
 		local spaces = -match:len()
@@ -180,7 +182,7 @@ function detab(text)
 end
 
 -- Applies string.find for every pattern in the list and returns the first match
-function find_first(s, patterns, index)
+local function find_first(s, patterns, index)
 	local res = {}
 	for _,p in ipairs(patterns) do
 		local match = {s:find(p, index)}
@@ -192,7 +194,7 @@ end
 -- If a replacement array is specified, the range [start, stop] in the array is replaced
 -- with the replacement array and the resulting array is returned. Without a replacement
 -- array the section of the array between start and stop is returned.
-function splice(array, start, stop, replacement)
+local function splice(array, start, stop, replacement)
 	if replacement then
 		local n = stop - start + 1
 		while n > 0 do
@@ -213,7 +215,7 @@ function splice(array, start, stop, replacement)
 end
 
 -- Outdents the text one step.
-function outdent(text)
+local function outdent(text)
 	text = "\n" .. text
 	text = text:gsub("\n  ? ? ?", "\n")
 	text = text:sub(2)
@@ -221,15 +223,15 @@ function outdent(text)
 end
 
 -- Indents the text one step.
-function indent(text)
+local function indent(text)
 	text = text:gsub("\n", "\n    ")
 	return text
 end
 
--- Does a simple tokenization of html data. Returns the data as a list of tokens. 
+-- Does a simple tokenization of html data. Returns the data as a list of tokens.
 -- Each token is a table with a type field (which is either "tag" or "text") and
 -- a text field (which contains the original token data).
-function tokenize_html(html)
+local function tokenize_html(html)
 	local tokens = {}
 	local pos = 1
 	while true do
@@ -239,7 +241,7 @@ function tokenize_html(html)
 			break
 		end
 		if start ~= pos then table.insert(tokens, {type="text", text = html:sub(pos, start-1)}) end
-		
+
 		local _, stop
 		if html:match("^<!%-%-", start) then
 			_,stop = html:find("%-%->", start)
@@ -249,7 +251,7 @@ function tokenize_html(html)
 			_,stop = html:find("%b<>", start)
 		end
 		if not stop then
-			-- error("Could not match html tag " .. html:sub(start,start+30)) 
+			-- error("Could not match html tag " .. html:sub(start,start+30))
 		 	table.insert(tokens, {type="text", text=html:sub(start, start)})
 			pos = start + 1
 		else
@@ -272,27 +274,27 @@ end
 local HASH = {
 	-- Has the hash been inited.
 	inited = false,
-	
+
 	-- The unique string prepended to all hash values. This is to ensure
 	-- that hash values do not accidently coincide with an actual existing
 	-- string in the document.
 	identifier = "",
-	
+
 	-- Counter that counts up for each new hash instance.
 	counter = 0,
-	
+
 	-- Hash table.
 	table = {}
 }
 
 -- Inits hashing. Creates a hash_identifier that doesn't occur anywhere
 -- in the text.
-function init_hash(text)
+local function init_hash(text)
 	HASH.inited = true
 	HASH.identifier = ""
 	HASH.counter = 0
 	HASH.table = {}
-	
+
 	local s = "HASH"
 	local counter = 0
 	local id
@@ -305,7 +307,7 @@ function init_hash(text)
 end
 
 -- Returns the hashed value for s.
-function hash(s)
+local function hash(s)
 	assert(HASH.inited)
 	if not HASH.table[s] then
 		HASH.counter = HASH.counter + 1
@@ -320,7 +322,7 @@ end
 ----------------------------------------------------------------------
 
 -- The protection module is used to "protect" parts of a document
--- so that they are not modified by subsequent processing steps. 
+-- so that they are not modified by subsequent processing steps.
 -- Protected parts are saved in a table for later unprotection
 
 -- Protection data
@@ -342,18 +344,18 @@ local PD = {
 --        Nested data.
 --     </div>
 -- </div>
-function block_pattern(tag)
+local function block_pattern(tag)
 	return "\n<" .. tag .. ".-\n</" .. tag .. ">[ \t]*\n"
 end
 
 -- Pattern for matching a block tag that begins and ends with a newline
-function line_pattern(tag)
+local function line_pattern(tag)
 	return "\n<" .. tag .. ".-</" .. tag .. ">[ \t]*\n"
 end
 
 -- Protects the range of characters from start to stop in the text and
 -- returns the protected string.
-function protect_range(text, start, stop)
+local function protect_range(text, start, stop)
 	local s = text:sub(start, stop)
 	local h = hash(s)
 	PD.blocks[h] = s
@@ -363,7 +365,7 @@ end
 
 -- Protect every part of the text that matches any of the patterns. The first
 -- matching pattern is protected first, etc.
-function protect_matches(text, patterns)
+local function protect_matches(text, patterns)
 	while true do
 		local start, stop = find_first(text, patterns)
 		if not start then break end
@@ -373,7 +375,7 @@ function protect_matches(text, patterns)
 end
 
 -- Protects blocklevel tags in the specified text
-function protect(text)
+local function protect(text)
 	-- First protect potentially nested block tags
 	text = protect_matches(text, map(PD.tags, block_pattern))
 	-- Then protect block tags at the line level.
@@ -385,12 +387,12 @@ function protect(text)
 end
 
 -- Returns true if the string s is a hash resulting from protection
-function is_protected(s)
+local function is_protected(s)
 	return PD.blocks[s]
 end
 
 -- Unprotects the specified text by expanding all the nonces
-function unprotect(text)
+local function unprotect(text)
 	for k,v in pairs(PD.blocks) do
 		v = v:gsub("%%", "%%%%")
 		text = text:gsub(k, v)
@@ -410,22 +412,22 @@ end
 -- Returns true if the line is a ruler of (char) characters.
 -- The line must contain at least three char characters and contain only spaces and
 -- char characters.
-function is_ruler_of(line, char)
+local function is_ruler_of(line, char)
 	if not line:match("^[ %" .. char .. "]*$") then return false end
 	if not line:match("%" .. char .. ".*%" .. char .. ".*%" .. char) then return false end
 	return true
 end
 
 -- Identifies the block level formatting present in the line
-function classify(line)
+local function classify(line)
 	local info = {line = line, text = line}
-	
+
 	if line:match("^    ") then
 		info.type = "indented"
 		info.outdented = line:sub(5)
 		return info
 	end
-	
+
 	for _,c in ipairs({'*', '-', '_', '='}) do
 		if is_ruler_of(line, c) then
 			info.type = "ruler"
@@ -433,12 +435,12 @@ function classify(line)
 			return info
 		end
 	end
-	
+
 	if line == "" then
 		info.type = "blank"
 		return info
 	end
-	
+
 	if line:match("^(#+)[ \t]*(.-)[ \t]*#*[ \t]*$") then
 		local m1, m2 = line:match("^(#+)[ \t]*(.-)[ \t]*#*[ \t]*$")
 		info.type = "header"
@@ -446,7 +448,7 @@ function classify(line)
 		info.text = m2
 		return info
 	end
-	
+
 	if line:match("^ ? ? ?(%d+)%.[ \t]+(.+)") then
 		local number, text = line:match("^ ? ? ?(%d+)%.[ \t]+(.+)")
 		info.type = "list_item"
@@ -455,7 +457,7 @@ function classify(line)
 		info.text = text
 		return info
 	end
-	
+
 	if line:match("^ ? ? ?([%*%+%-])[ \t]+(.+)") then
 		local bullet, text = line:match("^ ? ? ?([%*%+%-])[ \t]+(.+)")
 		info.type = "list_item"
@@ -464,29 +466,29 @@ function classify(line)
 		info.text= text
 		return info
 	end
-	
+
 	if line:match("^>[ \t]?(.*)") then
 		info.type = "blockquote"
 		info.text = line:match("^>[ \t]?(.*)")
 		return info
 	end
-	
+
 	if is_protected(line) then
 		info.type = "raw"
 		info.html = unprotect(line)
 		return info
 	end
-	
+
 	info.type = "normal"
 	return info
 end
 
 -- Find headers constisting of a normal line followed by a ruler and converts them to
 -- header entries.
-function headers(array)
+local function headers(array)
 	local i = 1
 	while i <= #array - 1 do
-		if array[i].type  == "normal" and array[i+1].type == "ruler" and 
+		if array[i].type  == "normal" and array[i+1].type == "ruler" and
 			(array[i+1].ruler_char == "-" or array[i+1].ruler_char == "=") then
 			local info = {line = array[i].line}
 			info.text = info.line
@@ -500,8 +502,10 @@ function headers(array)
 	return array
 end
 
+local block_transform, blocks_to_html, encode_code, span_transform, encode_backslash_escapes
+
 -- Find list blocks and convert them to protected data blocks
-function lists(array, sublist)
+local function lists(array, sublist)
 	local function process_list(arr)
 		local function any_blanks(arr)
 			for i = 1, #arr do
@@ -509,7 +513,7 @@ function lists(array, sublist)
 			end
 			return false
 		end
-		
+
 		local function split_list_items(arr)
 			local acc = {arr[1]}
 			local res = {}
@@ -524,12 +528,12 @@ function lists(array, sublist)
 			table.insert(res, acc)
 			return res
 		end
-		
+
 		local function process_list_item(lines, block)
 			while lines[#lines].type == "blank" do
 				table.remove(lines)
 			end
-			
+
 			local itemtext = lines[1].text
 			for i=2,#lines do
 				itemtext = itemtext .. "\n" .. outdent(lines[i].line)
@@ -548,7 +552,7 @@ function lists(array, sublist)
 				return "    <li>" .. itemtext .. "</li>"
 			end
 		end
-		
+
 		local block_list = any_blanks(arr)
 		local items = split_list_items(arr)
 		local out = ""
@@ -561,7 +565,7 @@ function lists(array, sublist)
 			return "<ul>\n" .. out .. "</ul>"
 		end
 	end
-	
+
 	-- Finds the range of lines composing the first list in the array. A list
 	-- starts with (^ list_item) or (blank list_item) and ends with
 	-- (blank* $) or (blank normal).
@@ -586,7 +590,7 @@ function lists(array, sublist)
 		local function find_list_end(array, start)
 			local pos = #array
 			for i = start, #array-1 do
-				if array[i].type == "blank" and array[i+1].type ~= "list_item" 
+				if array[i].type == "blank" and array[i+1].type ~= "list_item"
 					and array[i+1].type ~= "indented" and array[i+1].type ~= "blank" then
 					pos = i-1
 					break
@@ -597,12 +601,12 @@ function lists(array, sublist)
 			end
 			return pos
 		end
-		
+
 		local start = find_list_start(array, sublist)
 		if not start then return nil end
 		return start, find_list_end(array, start)
 	end
-	
+
 	while true do
 		local start, stop = find_list(array, sublist)
 		if not start then break end
@@ -614,17 +618,17 @@ function lists(array, sublist)
 		}
 		array = splice(array, start, stop, {info})
 	end
-	
+
 	-- Convert any remaining list items to normal
 	for _,line in ipairs(array) do
 		if line.type == "list_item" then line.type = "normal" end
 	end
-	
+
 	return array
 end
 
 -- Find and convert blockquote markers.
-function blockquotes(lines)
+local function blockquotes(lines)
 	local function find_blockquote(lines)
 		local start
 		for i,line in ipairs(lines) do
@@ -634,7 +638,7 @@ function blockquotes(lines)
 			end
 		end
 		if not start then return nil end
-		
+
 		local stop = #lines
 		for i = start+1, #lines do
 			if lines[i].type == "blank" or lines[i].type == "blockquote" then
@@ -647,7 +651,7 @@ function blockquotes(lines)
 		while lines[stop].type == "blank" do stop = stop - 1 end
 		return start, stop
 	end
-	
+
 	local function process_blockquote(lines)
 		local raw = lines[1].text
 		for i = 2,#lines do
@@ -658,7 +662,7 @@ function blockquotes(lines)
 		return "<blockquote>\n    " .. bt ..
 			"\n</blockquote>"
 	end
-	
+
 	while true do
 		local start, stop = find_blockquote(lines)
 		if not start then break end
@@ -674,14 +678,14 @@ function blockquotes(lines)
 end
 
 -- Find and convert codeblocks.
-function codeblocks(lines)
+local function codeblocks(lines)
 	local function find_codeblock(lines)
 		local start
 		for i,line in ipairs(lines) do
 			if line.type == "indented" then start = i break end
 		end
 		if not start then return nil end
-		
+
 		local stop = #lines
 		for i = start+1, #lines do
 			if lines[i].type ~= "indented" and lines[i].type ~= "blank" then
@@ -692,7 +696,7 @@ function codeblocks(lines)
 		while lines[stop].type == "blank" do stop = stop - 1 end
 		return start, stop
 	end
-	
+
 	local function process_codeblock(lines)
 		local raw = detab(encode_code(outdent(lines[1].line)))
 		for i = 2,#lines do
@@ -700,7 +704,7 @@ function codeblocks(lines)
 		end
 		return "<pre><code>" .. raw .. "\n</code></pre>"
 	end
-	
+
 	while true do
 		local start, stop = find_codeblock(lines)
 		if not start then break end
@@ -727,12 +731,12 @@ function blocks_to_html(lines, no_paragraphs)
 			table.insert(out, line.html)
 		elseif line.type == "normal" then
 			local s = line.line
-			
+
 			while i+1 <= #lines and lines[i+1].type == "normal" do
 				i = i + 1
 				s = s .. "\n" .. lines[i].line
 			end
-			
+
 			if no_paragraphs then
 				table.insert(out, span_transform(s))
 			else
@@ -764,7 +768,7 @@ end
 
 -- Debug function for printing a line array to see the result
 -- of partial transforms.
-function print_lines(lines)
+local function print_lines(lines)
 	for i, line in ipairs(lines) do
 		print(i, line.type, line.text or line.line)
 	end
@@ -778,10 +782,10 @@ end
 
 -- These characters may need to be escaped because they have a special
 -- meaning in markdown.
-escape_chars = "'\\`*_{}[]()>#+-.!'"
+local escape_chars = "'\\`*_{}[]()>#+-.!'"
-escape_table = {}
+local escape_table = {}
 
-function init_escape_table()
+local function init_escape_table()
 	escape_table = {}
 	for i = 1,#escape_chars do
 		local c = escape_chars:sub(i,i)
@@ -790,17 +794,17 @@ function init_escape_table()
 end
 
 -- Adds a new escape to the escape table.
-function add_escape(text)
+local function add_escape(text)
 	if not escape_table[text] then
 		escape_table[text] = hash(text)
 	end
 	return escape_table[text]
-end	
+end
 
 -- Escape characters that should not be disturbed by markdown.
-function escape_special_chars(text)
+local function escape_special_chars(text)
 	local tokens = tokenize_html(text)
-	
+
 	local out = ""
 	for _, token in ipairs(tokens) do
 		local t = token.text
@@ -826,7 +830,7 @@ function encode_backslash_escapes(t)
 end
 
 -- Unescape characters that have been encoded.
-function unescape_special_chars(t)
+local function unescape_special_chars(t)
 	local tin = t
 	for k,v in pairs(escape_table) do
 		k = k:gsub("%%", "%%%%")
@@ -850,7 +854,7 @@ function encode_code(s)
 end
 
 -- Handle backtick blocks.
-function code_spans(s)
+local function code_spans(s)
 	s = s:gsub("\\\\", escape_table["\\"])
 	s = s:gsub("\\`", escape_table["`"])
 
@@ -880,7 +884,7 @@ function code_spans(s)
 end
 
 -- Encode alt text... enodes &, and ".
-function encode_alt(s)
+local function encode_alt(s)
 	if not s then return s end
 	s = s:gsub('&', '&amp;')
 	s = s:gsub('"', '&quot;')
@@ -888,8 +892,10 @@ function encode_alt(s)
 	return s
 end
 
+local link_database
+
 -- Handle image references
-function images(text)
+local function images(text)
 	local function reference_link(alt, id)
 		alt = encode_alt(alt:match("%b[]"):sub(2,-2))
 		id = id:match("%[(.*)%]"):lower()
@@ -902,7 +908,7 @@ function images(text)
 		if title then title = " title=\"" .. title .. "\"" else title = "" end
 		return add_escape ('<img src="' .. url .. '" alt="' .. alt .. '"' .. title .. "/>")
 	end
-	
+
 	local function inline_link(alt, link)
 		alt = encode_alt(alt:match("%b[]"):sub(2,-2))
 		local url, title = link:match("%(<?(.-)>?[ \t]*['\"](.+)['\"]")
@@ -915,14 +921,14 @@ function images(text)
 			return add_escape('<img src="' .. url .. '" alt="' .. alt .. '"/>')
 		end
 	end
-	
+
 	text = text:gsub("!(%b[])[ \t]*\n?[ \t]*(%b[])", reference_link)
 	text = text:gsub("!(%b[])(%b())", inline_link)
 	return text
 end
 
 -- Handle anchor references
-function anchors(text)
+local function anchors(text)
 	local function reference_link(text, id)
 		text = text:match("%b[]"):sub(2,-2)
 		id = id:match("%b[]"):sub(2,-2):lower()
@@ -935,7 +941,7 @@ function anchors(text)
 		if title then title = " title=\"" .. title .. "\"" else title = "" end
 		return add_escape("<a href=\"" .. url .. "\"" .. title .. ">") .. text .. add_escape("</a>")
 	end
-	
+
 	local function inline_link(text, link)
 		text = text:match("%b[]"):sub(2,-2)
 		local url, title = link:match("%(<?(.-)>?[ \t]*['\"](.+)['\"]")
@@ -948,14 +954,14 @@ function anchors(text)
 			return add_escape("<a href=\"" .. url .. "\">") .. text .. add_escape("</a>")
 		end
 	end
-	
+
 	text = text:gsub("(%b[])[ \t]*\n?[ \t]*(%b[])", reference_link)
 	text = text:gsub("(%b[])(%b())", inline_link)
 	return text
 end
 
 -- Handle auto links, i.e. <http://www.google.com/>.
-function auto_links(text)
+local function auto_links(text)
 	local function link(s)
 		return add_escape("<a href=\"" .. s .. "\">") .. s .. "</a>"
 	end
@@ -969,21 +975,21 @@ function auto_links(text)
 		local plain = {code = function(c) return c end, count = 0, rate = 0.1}
 		local codes = {hex, dec, plain}
 		local function swap(t,k1,k2) local temp = t[k2] t[k2] = t[k1] t[k1] = temp end
-		
+
 		local out = ""
 		for i = 1,s:len() do
 			for _,code in ipairs(codes) do code.count = code.count + code.rate end
 			if codes[1].count < codes[2].count then swap(codes,1,2) end
 			if codes[2].count < codes[3].count then swap(codes,2,3) end
 			if codes[1].count < codes[2].count then swap(codes,1,2) end
-			
+
 			local code = codes[1]
 			local c = s:sub(i,i)
 			-- Force encoding of "@" to make email address more invisible.
 			if c == "@" and code == plain then code = codes[2] end
 			out = out .. code.code(c)
 			code.count = code.count - 1
-		end	
+		end
 		return out
 	end
 	local function mail(s)
@@ -995,7 +1001,7 @@ function auto_links(text)
 	-- links
 	text = text:gsub("<(https?:[^'\">%s]+)>", link)
 	text = text:gsub("<(ftp:[^'\">%s]+)>", link)
-	
+
 	-- mail
 	text = text:gsub("<mailto:([^'\">%s]+)>", mail)
 	text = text:gsub("<([-.%w]+%@[-.%w]+)>", mail)
@@ -1004,7 +1010,7 @@ end
 
 -- Encode free standing amps (&) and angles (<)... note that this does not
 -- encode free >.
-function amps_and_angles(s)
+local function amps_and_angles(s)
 	-- encode amps not part of &..; expression
 	local pos = 1
 	while true do
@@ -1019,17 +1025,17 @@ function amps_and_angles(s)
 			pos = amp+1
 		end
 	end
-	
+
 	-- encode naked <'s
 	s = s:gsub("<([^a-zA-Z/?$!])", "&lt;%1")
 	s = s:gsub("<$", "&lt;")
-	
+
 	-- what about >, nothing done in the original markdown source to handle them
 	return s
 end
 
 -- Handles emphasis markers (* and _) in the text.
-function emphasis(text)
+local function emphasis(text)
 	for _, s in ipairs {"%*%*", "%_%_"} do
 		text = text:gsub(s .. "([^%s][%*%_]?)" .. s, "<strong>%1</strong>")
 		text = text:gsub(s .. "([^%s][^<>]-[^%s][%*%_]?)" .. s, "<strong>%1</strong>")
@@ -1044,7 +1050,7 @@ function emphasis(text)
 end
 
 -- Handles line break markers in the text.
-function line_breaks(text)
+local function line_breaks(text)
 	return text:gsub("  +\n", " <br/>\n")
 end
 
@@ -1067,28 +1073,28 @@ end
 
 -- Cleanup the text by normalizing some possible variations to make further
 -- processing easier.
-function cleanup(text)
+local function cleanup(text)
 	-- Standardize line endings
 	text = text:gsub("\r\n", "\n")  -- DOS to UNIX
 	text = text:gsub("\r", "\n")    -- Mac to UNIX
-	
+
 	-- Convert all tabs to spaces
 	text = detab(text)
-	
+
 	-- Strip lines with only spaces and tabs
 	while true do
 		local subs
 		text, subs = text:gsub("\n[ \t]+\n", "\n\n")
 		if subs == 0 then break end
 	end
-	
+
 	return "\n" .. text .. "\n"
 end
 
 -- Strips link definitions from the text and stores the data in a lookup table.
-function strip_link_definitions(text)
+local function strip_link_definitions(text)
 	local linkdb = {}
-	
+
 	local function link_def(id, url, title)
 		id = id:match("%[(.+)%]"):lower()
 		linkdb[id] = linkdb[id] or {}
@@ -1101,7 +1107,7 @@ function strip_link_definitions(text)
 	local def_title1 = def_no_title .. "[ \t]+\n?[ \t]*[\"'(]([^\n]+)[\"')][ \t]*"
 	local def_title2 = def_no_title .. "[ \t]*\n[ \t]*[\"'(]([^\n]+)[\"')][ \t]*"
 	local def_title3 = def_no_title .. "[ \t]*\n?[ \t]+[\"'(]([^\n]+)[\"')][ \t]*"
-	
+
 	text = text:gsub(def_title1, link_def)
 	text = text:gsub(def_title2, link_def)
 	text = text:gsub(def_title3, link_def)
@@ -1112,10 +1118,10 @@ end
 link_database = {}
 
 -- Main markdown processing function
-function markdown(text)
+local function markdown(text)
 	init_hash(text)
 	init_escape_table()
-	
+
 	text = cleanup(text)
 	text = protect(text)
 	text, link_database = strip_link_definitions(text)
@@ -1132,7 +1138,7 @@ setfenv(1, _G)
 M.lock(M)
 
 -- Expose markdown function to the world
-markdown = M.markdown
+_G.markdown = M.markdown
 
 -- Class for parsing command-line options
 local OptionParser = {}
@@ -1168,6 +1174,7 @@ end
 -- where successfully parsed and false otherwise.
 function OptionParser:run(args)
 	local pos = 1
+   local param
 	while pos <= #args do
 		local arg = args[pos]
 		if arg == "--" then
@@ -1225,7 +1232,7 @@ local function run_command_line(arg)
 		if not options.wrap_header then return s end
 		local header = ""
 		if options.header then
-			local f = io.open(options.header) or error("Could not open file: " .. options.header) 
+			local f = io.open(options.header) or error("Could not open file: " .. options.header)
 			header = f:read("*a")
 			f:close()
 		else
@@ -1239,14 +1246,14 @@ local function run_command_line(arg)
 </head>
 <body>
 ]]
-			local title = options.title or s:match("<h1>(.-)</h1>") or s:match("<h2>(.-)</h2>") or 
+			local title = options.title or s:match("<h1>(.-)</h1>") or s:match("<h2>(.-)</h2>") or
 				s:match("<h3>(.-)</h3>") or "Untitled"
 			header = header:gsub("TITLE", title)
 			if options.inline_style then
 				local style = ""
 				local f = io.open(options.stylesheet)
-				if f then 
+				if f then
-					style = f:read("*a") f:close() 
+					style = f:read("*a") f:close()
 				else
 					error("Could not include style sheet " .. options.stylesheet .. ": File not found")
 				end
@@ -1265,15 +1272,15 @@ local function run_command_line(arg)
 		end
 		return header .. s .. footer
 	end
-	
+
-	-- Generate output path name from input path name given options.	
+	-- Generate output path name from input path name given options.
 	local function outpath(path, options)
 		if options.append then return path .. ".html" end
 		local m = path:match("^(.+%.html)[^/\\]+$") if m then return m end
 		m = path:match("^(.+%.)[^/\\]*$") if m and path ~= m .. "html" then return m .. "html" end
 		return path .. ".html"
 	end
-	
+
 	-- Default commandline options
 	local options = {
 		wrap_header = true,
@@ -1316,18 +1323,18 @@ Other options:
 	op:param("s", "style", function(x) options.stylesheet = x end)
 	op:flag("l", "inline-style", function(x) options.inline_style = true end)
 	op:flag("a", "append", function() options.append = true end)
-	op:flag("t", "test", function() 
+	op:flag("t", "test", function()
 		local n = arg[0]:gsub("markdown.lua", "markdown-tests.lua")
 		local f = io.open(n)
-		if f then 
+		if f then
-			f:close() dofile(n) 
+			f:close() dofile(n)
 		else
 			error("Cannot find markdown-tests.lua")
 		end
-		run_stdin = false 
+		run_stdin = false
 	end)
 	op:flag("h", "help", function() print(help) run_stdin = false end)
-	op:arg(function(path) 
+	op:arg(function(path)
 			local file = io.open(path) or error("Could not open file: " .. path)
 			local s = file:read("*a")
 			file:close()
@@ -1338,7 +1345,7 @@ Other options:
 			run_stdin = false
 		end
 	)
-	
+
 	if not op:run(arg) then
 		print(help)
 		run_stdin = false
@@ -1350,10 +1357,10 @@ Other options:
 		io.write(s)
 	end
 end
-	
+
 -- If we are being run from the command-line, act accordingly
 if arg and arg[0]:find("markdown%.lua$") then
 	run_command_line(arg)
 else
 	return markdown
-end
+end