diff --git a/src/DomainParser.purs b/src/DomainParser.purs
index be6d495..7636a5a 100644
--- a/src/DomainParser.purs
+++ b/src/DomainParser.purs
@@ -1,10 +1,10 @@
 -- | `DomainParser` is a simple parser for domain names as described in RFC 1035.
 module DomainParser where
 
-import Prelude (bind, not, pure, ($), (&&), (*>), (<<<), (<>), (==), (>))
+import Prelude (bind, not, pure, ($), (&&), (*>), (<<<), (<>), (>))
 
 import Control.Lazy (defer)
-import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..), maybe)
 import Data.Either (Either(..))
 import Data.Array as A
 import Data.String as S
@@ -13,7 +13,8 @@ import Control.Alt ((<|>))
 import Control.Plus (empty)
 
 import Parser (Parser(..), Position
-              , success, fail, failError
+              , success, failError
+              , current_position
               , alphanum, char, letter, many1, parse, string)
 
 type Size = Int
@@ -54,11 +55,8 @@ parse_last_char s p = case last_char s of
     Left _  -> false
     _       -> true
 
--- | FIXME: This is flawed.
--- | We cannot know if it worked: in case there is a problem with the parser `p`,
--- | the code will "continue to work" but without what's been parsed.
--- | This may sound reasonable but it prevents knowing if a problem actually occured!
--- | We cannot do a `try parser <|> alternative` since it will always work!
+-- | `try` provides a way to accept a faulty parser and
+-- | just rewinds back to previous input state if an error occurs.
 try :: forall e a. Parser e a -> Parser e (Maybe a)
 try p = Parser p'
   where p' input = case parse p input of
@@ -70,9 +68,7 @@ label :: forall e. Parser e String
 label = do
   l <- letter
   s <- try ldh_str
-  let labelstr = CU.singleton l <> case s of
-                                     Nothing      -> ""
-                                     Just content -> CU.fromCharArray content
+  let labelstr = CU.singleton l <> maybe "" (\v -> CU.fromCharArray v) s
   if (S.length labelstr > label_maxsize)
   then empty
   else if (S.length labelstr > 1 && not (parse_last_char labelstr let_dig))
@@ -106,9 +102,10 @@ sub_eof = do
   sub <- subdomain
   maybe_final_point <- try $ char '.'
   _ <- eof -- In case there is still some input, it fails.
+  pos <- current_position
   let parsed_domain = did_we_parsed_the_final_point maybe_final_point sub
   if S.length parsed_domain > max_domain_length
-  then empty -- TODO: error management.
+  then Parser \_ -> failError pos (Just <<< DomainTooLarge $ S.length parsed_domain)
   else pure parsed_domain
   where
     did_we_parsed_the_final_point Nothing sub = sub
diff --git a/src/Main.purs b/src/Main.purs
index 983da83..0647a28 100644
--- a/src/Main.purs
+++ b/src/Main.purs
@@ -1,7 +1,7 @@
 module Main where
 
 import Parser (Parser(..))
-import DomainParser (domain, label, ldh_str, sub_eof, subdomain)
+import DomainParser (domain, label, ldh_str, sub_eof, subdomain, DomainError(..))
 
 import Prelude (Unit, discard, show, ($), (<>))
 
@@ -9,7 +9,7 @@ import Effect (Effect)
 import Effect.Console (log)
 
 import Data.Either (Either(..))
---import Data.Maybe (Maybe(..))
+import Data.Maybe (Maybe(..))
 --import Data.Tuple (Tuple(..))
 
 import Data.String.CodeUnits (fromCharArray)
@@ -39,112 +39,120 @@ import Data.String.CodeUnits (fromCharArray)
 --     let toprint = if b then "FOUND IT" else "not found"
 --     log $ toprint <> ", rest: " <> str
 
-logtest :: forall e v. String -> Parser e v -> String -> (v -> String) -> Effect Unit
-logtest fname (Parser p) str r = do
+logtest :: forall e v. String -> Parser e v -> String -> (v -> String) -> (e -> String) -> Effect Unit
+logtest fname (Parser p) str r e = do
   log $ "(" <> fname <> ") parsing '" <> str <> "': "
     <> case p { string: str, position: 0 } of
-      Left  { position, error: _ } -> "failed at position " <> show position
+      Left  { position, error } -> "failed at position " <> show position <> case error of
+        Nothing  -> " -> no error reported"
+        Just err -> " -> error: " <> e err
       Right { suffix, result } -> show (r result) <> " '" <> suffix.string <> "'"
 
 id :: forall a. a -> a
 id a = a
 
+showerror :: DomainError -> String
+showerror (SubdomainTooLarge position size) = "SubdomainTooLarge (position: " <> show position <> ", size: " <> show size <> ")"
+showerror (DomainTooLarge size)             = "DomainTooLarge (size: " <> show size <> ")"
+showerror (InvalidCharacter position)       = "InvalidCharacter (position: " <> show position <> ")"
+showerror (EOFExpected)                     = "EOFExpected"
+
 main :: Effect Unit
 main = do
-  logtest "ldh_str" ldh_str "a12B.fl" fromCharArray
-  logtest "ldh_str" ldh_str "1efg.x1" fromCharArray
-  logtest "ldh_str" ldh_str ".qjzleb" fromCharArray
-  logtest "ldh_str" ldh_str "a-b.b-a" fromCharArray
-  logtest "ldh_str" ldh_str "" fromCharArray
+  logtest "ldh_str" ldh_str "a12B.fl" fromCharArray showerror 
+  logtest "ldh_str" ldh_str "1efg.x1" fromCharArray showerror 
+  logtest "ldh_str" ldh_str ".qjzleb" fromCharArray showerror 
+  logtest "ldh_str" ldh_str "a-b.b-a" fromCharArray showerror 
+  logtest "ldh_str" ldh_str "" fromCharArray showerror 
 
   log ""
 
-  logtest "label" label "example.org" id
-  logtest "label" label "" id
-  logtest "label" label "a.x" id
-  logtest "label" label "a2.org" id
-  logtest "label" label "a33.org" id
-  logtest "label" label "a444.org" id
-  logtest "label" label "a5555.org" id
-  logtest "label" label "a66666.org" id
-  logtest "label" label "a777777.org" id
-  logtest "label" label "a8888888.org" id
+  logtest "label" label "example.org" id showerror 
+  logtest "label" label "" id showerror 
+  logtest "label" label "a.x" id showerror 
+  logtest "label" label "a2.org" id showerror 
+  logtest "label" label "a33.org" id showerror 
+  logtest "label" label "a444.org" id showerror 
+  logtest "label" label "a5555.org" id showerror 
+  logtest "label" label "a66666.org" id showerror 
+  logtest "label" label "a777777.org" id showerror 
+  logtest "label" label "a8888888.org" id showerror 
   log ""
-  logtest "label" label "-" id
-  logtest "label" label "a-" id
+  logtest "label" label "-" id showerror 
+  logtest "label" label "a-" id showerror 
 
   log ""
 
-  logtest "subdomain" subdomain "example.org" id
-  logtest "subdomain" subdomain "" id
-  logtest "subdomain" subdomain "a.x" id
-  logtest "subdomain" subdomain "a2.org" id
-  logtest "subdomain" subdomain "a33.org" id
-  logtest "subdomain" subdomain "a444.org" id
-  logtest "subdomain" subdomain "a5555.org" id
-  logtest "subdomain" subdomain "a66666.org" id
-  logtest "subdomain" subdomain "a777777.org" id
-  logtest "subdomain" subdomain "a8888888.org" id
-  logtest "subdomain" subdomain "xblah.a.x" id
-  logtest "subdomain" subdomain "xblah.a2.org" id
-  logtest "subdomain" subdomain "xblah.a33.org" id
-  logtest "subdomain" subdomain "xblah.a444.org" id
-  logtest "subdomain" subdomain "xblah.a5555.org" id
-  logtest "subdomain" subdomain "xblah.a66666.org" id
-  logtest "subdomain" subdomain "xblah.a777777.org" id
-  logtest "subdomain" subdomain "xblah.a8888888.org" id
-  logtest "subdomain" subdomain "-" id
-  logtest "subdomain" subdomain "a-" id
+  logtest "subdomain" subdomain "example.org" id showerror 
+  logtest "subdomain" subdomain "" id showerror 
+  logtest "subdomain" subdomain "a.x" id showerror 
+  logtest "subdomain" subdomain "a2.org" id showerror 
+  logtest "subdomain" subdomain "a33.org" id showerror 
+  logtest "subdomain" subdomain "a444.org" id showerror 
+  logtest "subdomain" subdomain "a5555.org" id showerror 
+  logtest "subdomain" subdomain "a66666.org" id showerror 
+  logtest "subdomain" subdomain "a777777.org" id showerror 
+  logtest "subdomain" subdomain "a8888888.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a.x" id showerror 
+  logtest "subdomain" subdomain "xblah.a2.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a33.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a444.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a5555.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a66666.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a777777.org" id showerror 
+  logtest "subdomain" subdomain "xblah.a8888888.org" id showerror 
+  logtest "subdomain" subdomain "-" id showerror 
+  logtest "subdomain" subdomain "a-" id showerror 
 
   log ""
 
-  logtest "sub_eof" sub_eof " " id
-  logtest "sub_eof" sub_eof "  " id
-  logtest "sub_eof" sub_eof "example.org" id
-  logtest "sub_eof" sub_eof "" id
-  logtest "sub_eof" sub_eof "a.x" id
-  logtest "sub_eof" sub_eof "a2.org" id
-  logtest "sub_eof" sub_eof "a33.org" id
-  logtest "sub_eof" sub_eof "a444.org" id
-  logtest "sub_eof" sub_eof "a5555.org" id
-  logtest "sub_eof" sub_eof "a66666.org" id
-  logtest "sub_eof" sub_eof "a777777.org" id
-  logtest "sub_eof" sub_eof "a8888888.org" id
-  logtest "sub_eof" sub_eof "xblah.a.x" id
-  logtest "sub_eof" sub_eof "xblah.a2.org" id
-  logtest "sub_eof" sub_eof "xblah.a33.org" id
-  logtest "sub_eof" sub_eof "xblah.a444.org" id
-  logtest "sub_eof" sub_eof "xblah.a5555.org" id
-  logtest "sub_eof" sub_eof "xblah.a66666.org" id
-  logtest "sub_eof" sub_eof "xblah.a777777.org" id
-  logtest "sub_eof" sub_eof "xblah.a8888888.org" id
-  logtest "sub_eof" sub_eof "-" id
-  logtest "sub_eof" sub_eof "a-" id
+  logtest "sub_eof" sub_eof " " id showerror 
+  logtest "sub_eof" sub_eof "  " id showerror 
+  logtest "sub_eof" sub_eof "example.org" id showerror 
+  logtest "sub_eof" sub_eof "" id showerror 
+  logtest "sub_eof" sub_eof "a.x" id showerror 
+  logtest "sub_eof" sub_eof "a2.org" id showerror 
+  logtest "sub_eof" sub_eof "a33.org" id showerror 
+  logtest "sub_eof" sub_eof "a444.org" id showerror 
+  logtest "sub_eof" sub_eof "a5555.org" id showerror 
+  logtest "sub_eof" sub_eof "a66666.org" id showerror 
+  logtest "sub_eof" sub_eof "a777777.org" id showerror 
+  logtest "sub_eof" sub_eof "a8888888.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a.x" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a2.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a33.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a444.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a5555.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a66666.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a777777.org" id showerror 
+  logtest "sub_eof" sub_eof "xblah.a8888888.org" id showerror 
+  logtest "sub_eof" sub_eof "-" id showerror 
+  logtest "sub_eof" sub_eof "a-" id showerror 
 
   log ""
 
-  logtest "domain" domain " " id
-  logtest "domain" domain "  " id
-  logtest "domain" domain "example.org" id
-  logtest "domain" domain "" id
-  logtest "domain" domain "a.x" id
-  logtest "domain" domain "a2.org" id
-  logtest "domain" domain "a33.org" id
-  logtest "domain" domain "a444.org" id
-  logtest "domain" domain "a5555.org" id
-  logtest "domain" domain "a66666.org" id
-  logtest "domain" domain "a777777.org" id
-  logtest "domain" domain "a8888888.org" id
-  logtest "domain" domain "xblah.a.x" id
-  logtest "domain" domain "xblah.a2.org" id
-  logtest "domain" domain "xblah.a33.org" id
-  logtest "domain" domain "xblah.a444.org" id
-  logtest "domain" domain "xblah.a5555.org" id
-  logtest "domain" domain "xblah.a66666.org" id
-  logtest "domain" domain "xblah.a777777.org" id
-  logtest "domain" domain "xblah.a8888888.org" id
-  logtest "domain" domain "-" id
-  logtest "domain" domain "a-" id
+  logtest "domain" domain " " id showerror 
+  logtest "domain" domain "  " id showerror 
+  logtest "domain" domain "example.org" id showerror 
+  logtest "domain" domain "" id showerror 
+  logtest "domain" domain "a.x" id showerror 
+  logtest "domain" domain "a2.org" id showerror 
+  logtest "domain" domain "a33.org" id showerror 
+  logtest "domain" domain "a444.org" id showerror 
+  logtest "domain" domain "a5555.org" id showerror 
+  logtest "domain" domain "a66666.org" id showerror 
+  logtest "domain" domain "a777777.org" id showerror 
+  logtest "domain" domain "a8888888.org" id showerror 
+  logtest "domain" domain "xblah.a.x" id showerror 
+  logtest "domain" domain "xblah.a2.org" id showerror 
+  logtest "domain" domain "xblah.a33.org" id showerror 
+  logtest "domain" domain "xblah.a444.org" id showerror 
+  logtest "domain" domain "xblah.a5555.org" id showerror 
+  logtest "domain" domain "xblah.a66666.org" id showerror 
+  logtest "domain" domain "xblah.a777777.org" id showerror 
+  logtest "domain" domain "xblah.a8888888.org" id showerror 
+  logtest "domain" domain "-" id showerror 
+  logtest "domain" domain "a-" id showerror 
 
 --  log $ "parsing the first 'f' in 'fiction' (sat): " <> case parse (sat (\x -> x == 'f')) "fiction" of
 --    Just (Tuple x y) -> show x <> " " <> show y
diff --git a/src/Parser.purs b/src/Parser.purs
index 846abd4..889f0cf 100644
--- a/src/Parser.purs
+++ b/src/Parser.purs
@@ -11,7 +11,6 @@ import Data.Int as Int
 import Data.Either (Either(..))
 import Data.Maybe (Maybe(..))
 import Data.String.CodeUnits (toCharArray, fromCharArray)
--- import Data.Tuple (Tuple(..))
 
 import BaseFunctions (concat, isAlpha, isAlphaNum, isDigit, isLower, isSpace, isUpper)
 
@@ -28,9 +27,11 @@ newtype Parser e v = Parser (Input -> Result e v)
 parse :: forall e v. Parser e v -> (Input -> Result e v)
 parse (Parser p) = p
 
+current_position :: forall e. Parser e Position
+current_position = Parser \input -> success input input.position
+
 -- | Fail with a specified error.
 -- | When a parsing has a specified error, no alternative will be tried and the error is reported.
--- TODO: stop the parsing when an error is provided.
 failError :: forall e v. Position -> Maybe e -> Result e v
 failError position error = Left { position, error }
 
@@ -39,7 +40,6 @@ failError position error = Left { position, error }
 -- | such as `digit` or `letter`.
 -- | Also, this can be used to express a possibly expected invalid parsing that should not
 -- | halt the parsing, but rather let an alternative path to be tried.
--- TODO: stop the parsing when an error is provided.
 fail :: forall e v. Position -> Result e v
 fail position = failError position Nothing