diff --git a/app/Main.hs b/app/Main.hs
index 05d1fd1..1b4c972 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,121 +1,8 @@
 module Main where
 
-import Text.ParserCombinators.ReadP
-import Control.Monad
-import Control.Applicative
-import Text.Printf
-import Debug.Trace
-import Data.List
-
-type HeaderLevel = Int
-
-newtype URL = URL {getUrl :: String}
-newtype ImgPath = ImgPath {getPath :: String}
-
-parseMany :: ReadP a -> ReadP [a]
-parseMany = Text.ParserCombinators.ReadP.many
-
-data MdToken = Header HeaderLevel MdToken
-             | Para [MdToken]
-             | Linebreak
-             | HorizontalRule
-             | Blockquote MdToken
-             | UnordList [MdToken]
-             | OrdList [MdToken]
-             | Code String
-             | Codeblock String
-             | Link MdToken URL
-             | Image MdToken ImgPath
-             | Bold MdToken
-             | Italic MdToken
-             | Strikethrough MdToken
-             | Unit String
-
--- Deriving Show for MdToken
-instance Show MdToken where
-    show (Header level token) = "<h" ++ show level ++ ">" ++ show token ++ "</h" ++ show level ++ ">"
-    show (Para tokens) = concat(map show tokens)
-    show Linebreak = "\n"
-    show HorizontalRule = "---------"
-    show (Blockquote token) = "BLOCK" ++ show token
-    show (UnordList tokens) = "UNORD" ++ concat(map show tokens)
-    show (OrdList tokens) = "ORD" ++ concat(map show tokens)
-    show (Code code) = show code
-    show (Codeblock code) = show code
-    show (Link txt url) = "<a href=" ++ (getUrl url) ++ ">" ++ show txt ++ "</a>"
-    show (Image txt path) = "<img src=" ++ (getPath path) ++ ">" ++ show txt ++ "</img>"
-    show (Bold token) = "<b>" ++ show token ++ "</b>"
-    show (Italic token) = "<i>" ++ show token ++ "</i>"
-    show (Strikethrough token) = "<s>" ++ show token ++ "</s>"
-    show (Unit unit) = printf "%s" unit
-
-
-
--- ---------------
--- Helpers
-mustBeHash :: ReadP Char
-mustBeHash = satisfy (\x -> x == '#')
-
-leftmostLongest :: (Foldable t) => [(a, t b)] -> (a, t b)
-leftmostLongest xs = 
-        let lastElem = (last xs)
-            filteredLst = (filter (\val -> (length $ snd val) == (length $ snd lastElem)) xs)
-        in head filteredLst
-
-leftmostLongestParse :: ReadP a -> String -> (a, String)
-leftmostLongestParse parser input = leftmostLongest $ readP_to_S parser input 
--- ---------------
-
-parseHeader :: ReadP MdToken
-parseHeader = do
-        headers <- many1 mustBeHash
-        when ((length headers) > 6)
-            pfail
-        _ <- string " "
-        text <- munch1 (\x -> x /= '\n') -- Parse until EOL
---        traceM text
-        let parsedText = fst  $ leftmostLongestParse parseLine text
-        return (Header (length headers) parsedText)
-                
-parseBold :: ReadP MdToken
-parseBold = do
-        text <- choice[
-                       (between (string "__") (string "__") (munch1 (/= '_'))), 
-                       (between (string "**") (string "**") (munch1 (/= '*')))
-                       ]
---        text <- munch1 (\x -> x /= '_' && x /= '*') -- Parse until first asterisk/underscore
- --       traceM text
-        -- _ <- char '_' <|> char '*' -- Throw away the second asterisk/underscore
-        let parsedText = fst  $ leftmostLongestParse parseLine text
-        return (Bold parsedText)
-
-parseItalic :: ReadP MdToken
-parseItalic = do
-        text <- choice[
-                       (between (string "_") (string "_") (munch1 (/= '_'))), 
-                       (between (string "*") (string "*") (munch1 (/= '*')))
-                       ]
-        let parsedText = fst $ leftmostLongestParse parseLine text
-        return (Italic parsedText)
-
-parseString :: ReadP MdToken
-parseString = do
-         firstChar <- get -- Must parse at least one character here
-         text <- munch (\x -> not (elem x "#*_[\n"))
-         return (Unit (firstChar:text))
-         --return (Unit text)
-
-parseToken :: ReadP MdToken
-parseToken = choice [parseHeader, parseBold, parseItalic, parseString]
-
-parseLine :: ReadP MdToken
-parseLine =  do
-         parsed <- parseMany parseToken
---         traceM $ show parsed
-         return (Para parsed)
-            
+import MdToHTML
 
 main :: IO ()
 main = do
-   let res = leftmostLongestParse parseLine "## Hello __world_*"
+   let res = leftmostLongestParse parseLine "## Hello ___world___"
    putStrLn (show res)
diff --git a/src/MdToHtml.hs b/src/MdToHtml.hs
new file mode 100644
index 0000000..568b6f0
--- /dev/null
+++ b/src/MdToHtml.hs
@@ -0,0 +1,149 @@
+module MdToHTML where
+
+import Text.ParserCombinators.ReadP
+import Control.Monad
+import Control.Applicative
+import Text.Printf
+import Debug.Trace
+import Data.List
+
+type HeaderLevel = Int
+
+newtype URL = URL {getUrl :: String}
+newtype ImgPath = ImgPath {getPath :: String}
+
+parseMany :: ReadP a -> ReadP [a]
+parseMany = Text.ParserCombinators.ReadP.many
+
+data MdToken = Header HeaderLevel MdToken
+             | Para MdToken
+             | Line [MdToken]
+             | Linebreak
+             | HorizontalRule
+             | Blockquote MdToken
+             | UnordList [MdToken]
+             | OrdList [MdToken]
+             | Code String
+             | Codeblock String
+             | Link MdToken URL
+             | Image MdToken ImgPath
+             | Bold MdToken
+             | Italic MdToken
+             | Strikethrough MdToken
+             | Unit String
+
+-- Deriving Show for MdToken
+instance Show MdToken where
+    show (Header level token) = "<h" ++ show level ++ ">" ++ show token ++ "</h" ++ show level ++ ">"
+    show (Para token) = "<p>" ++ show token ++ "</p>"
+    show (Line tokens) =  concat(map show tokens)
+    show Linebreak = "<br>"
+    show HorizontalRule = "---------"
+    show (Blockquote token) = "BLOCK" ++ show token
+    show (UnordList tokens) = "UNORD" ++ concat(map show tokens)
+    show (OrdList tokens) = "ORD" ++ concat(map show tokens)
+    show (Code code) = show code
+    show (Codeblock code) = show code
+    show (Link txt url) = "<a href=" ++ (getUrl url) ++ ">" ++ show txt ++ "</a>"
+    show (Image txt imgPath) = "<img src=" ++ (getPath imgPath) ++ ">" ++ show txt ++ "</img>"
+    show (Bold token) = "<b>" ++ show token ++ "</b>"
+    show (Italic token) = "<i>" ++ show token ++ "</i>"
+    show (Strikethrough token) = "<s>" ++ show token ++ "</s>"
+    show (Unit unit) = printf "%s" unit
+
+
+
+-- ---------------
+-- Helpers
+mustBeHash :: ReadP Char
+mustBeHash = satisfy (\x -> x == '#')
+
+leftmostLongest :: (Foldable t) => [(a, t b)] -> (a, t b)
+leftmostLongest xs = 
+        let lastElem = (last xs)
+            filteredLst = (filter (\val -> (length $ snd val) == (length $ snd lastElem)) xs)
+        in head filteredLst
+
+-- Get the first parse returned by readP_to_S that consumed the most input
+leftmostLongestParse :: ReadP a -> String -> (a, String)
+leftmostLongestParse parser input = leftmostLongest $ readP_to_S parser input 
+
+-- Parse if the string that's left matches the string comparator function
+lookaheadParse :: (String -> Bool) -> ReadP Char
+lookaheadParse stringCmp = do
+               lookahead <- look
+               case stringCmp lookahead of
+                  True -> get
+                  False -> pfail
+
+lineToList :: MdToken -> [MdToken]
+lineToList (Line tokens) = tokens
+-- --------------- 
+
+-- Parse a markdown header, denoted by 1-6 #'s followed by some text, followed by EOL.
+parseHeader :: ReadP MdToken
+parseHeader = do
+        headers <- many1 mustBeHash
+        when ((length headers) > 6)
+            pfail
+        _ <- string " "
+        text <- munch1 (\x -> x /= '\n') -- Parse until EOL
+--        traceM text
+        let parsedText = fst  $ leftmostLongestParse parseLine text
+        return (Header (length headers) parsedText)
+                
+-- Parse bold text
+parseBold :: ReadP MdToken
+parseBold = do
+        text <- choice[
+                       (between (string "__") (string "__") (many1 (lookaheadParse (/= "__")))),
+                       (between (string "**") (string "**") (many1 (lookaheadParse (/= "**"))))
+                       ]
+        let parsedText = fst  $ leftmostLongestParse parseLine text
+        return (Bold parsedText)
+
+-- Parse italic text
+parseItalic :: ReadP MdToken
+parseItalic = do
+        text <- choice[
+                       (between (string "_") (string "_") (munch1 (/= '_'))), 
+                       (between (string "*") (string "*") (munch1 (/= '*')))
+                       ]
+        let parsedText = fst $ leftmostLongestParse parseLine text
+        return (Italic parsedText)
+
+-- Parse a linebreak character
+parseLinebreak :: ReadP MdToken
+parseLinebreak = do
+           char '\n'
+           return Linebreak
+
+-- Parse a regular string as a Unit.
+parseString :: ReadP MdToken
+parseString = do
+         firstChar <- get -- Must parse at least one character here
+         text <- munch (\x -> not (elem x "#*_[\n"))
+         return (Unit (firstChar:text))
+
+-- Parse any of the above tokens.
+parseToken :: ReadP MdToken
+parseToken = choice [parseHeader, parseLinebreak, parseBold, parseItalic, parseString]
+
+-- Parse a line, consisting of one or more tokens.
+parseLine :: ReadP MdToken
+parseLine =  do
+         remaining <- look
+         when (null remaining) pfail
+         parsed <- parseMany parseToken
+--         traceM $ show parsed
+         return (Line parsed)
+
+-- Parse a paragraph, which is a 'Line' (can span multiple actual lines), separated by double-newlines.
+parsePara :: ReadP MdToken
+parsePara = do
+           parseMany (char '\n')
+           text <- many1 (lookaheadParse (\x -> ((length x) < 2) || (take 2 x) /= "\n\n"))
+           string "\n\n"
+           -- I don't consume the ending double-newline, because the next paragraph will consume it as part of its starting double-newline.
+           let parsedText = fst $ leftmostLongestParse parseLine text
+           return (Para parsedText)
diff --git a/src/Test.hs b/src/Test.hs
new file mode 100644
index 0000000..e4333d1
--- /dev/null
+++ b/src/Test.hs
@@ -0,0 +1,22 @@
+module MdToHtmlTest where
+
+import MdToHTML
+import Test.HUnit
+
+headerTests = TestList
+      [
+         (TestCase (assertEqual "Should convert H1 heading" "<h1>Hello</h1>" (show . fst $ leftmostLongestParse parseLine "# Hello"))),
+         (TestCase (assertEqual "Should convert H2 heading" "<h2>Hello</h2>" (show . fst $ leftmostLongestParse parseLine "## Hello"))),
+         (TestCase (assertEqual "Should convert H3 heading" "<h3>Hello</h3>" (show . fst $ leftmostLongestParse parseLine "### Hello"))),
+         (TestCase (assertEqual "Should convert H4 heading" "<h4>Hello</h4>" (show . fst $ leftmostLongestParse parseLine "#### Hello"))),
+         (TestCase (assertEqual "Should convert H5 heading" "<h5>Hello</h5>" (show . fst $ leftmostLongestParse parseLine "##### Hello"))),
+         (TestCase (assertEqual "Should convert H6 heading" "<h6>Hello</h6>" (show . fst $ leftmostLongestParse parseLine "###### Hello")))
+      ]
+
+
+tests = TestList
+   [
+      headerTests
+   ]
+
+runTests = runTestTT tests