diff --git a/Language/Haskell/Homplexity/Assessment.hs b/Language/Haskell/Homplexity/Assessment.hs
--- a/Language/Haskell/Homplexity/Assessment.hs
+++ b/Language/Haskell/Homplexity/Assessment.hs
@@ -11,7 +11,8 @@
 -- | Main module parsing inputs, and running analysis.
 module Language.Haskell.Homplexity.Assessment (
     metrics
-  , measureAllOccurs) where
+  --, measureAllOccurs
+  ) where
 
 import Data.Data
 import Data.Monoid
@@ -46,9 +47,18 @@
 measureTopOccurs assess = measureAll assess occurs
 
 --measureAllOccurs  :: (CodeFragment c, Metric m c) => Severity -> Proxy m -> Proxy c -> Program -> Log
+-- | Measure all occurences of a given @CodeFragment@ with a given @Metric@,
+-- then use @Assessment@ on them and give a list of @Log@ messages.
+--
+-- Arguments come in the following order:
+-- 1. @Assessment@ for the value of the @Metric@.
+-- 2. @Metric@ given as @Proxy@ type.
+-- 3. @CodeFragment@ given as @Proxy@ type.
+-- 4. Program containing @CodeFragment@s.
 measureAllOccurs :: (Data from, Metric m c) => Assessment m -> Proxy m -> Proxy c -> from -> Log
 measureAllOccurs assess = measureAll assess allOccurs
 
+-- | Type of functions that convert a @Metric@ into a log message.
 type Assessment m = m -> (Severity, String)
 
 warnOfMeasure :: (CodeFragment c, Metric m c) => Assessment m -> Proxy m -> Proxy c -> c -> Log
diff --git a/Language/Haskell/Homplexity/CodeFragment.hs b/Language/Haskell/Homplexity/CodeFragment.hs
--- a/Language/Haskell/Homplexity/CodeFragment.hs
+++ b/Language/Haskell/Homplexity/CodeFragment.hs
@@ -98,6 +98,7 @@
   fragmentSlice ::     c -> SrcSlice
   fragmentSlice  = srcSlice
 
+-- | First location for each @CodeFragment@ - for convenient reporting.
 fragmentLoc :: (CodeFragment c) => c -> SrcLoc
 fragmentLoc =  getPointLoc
             .  fragmentSlice
diff --git a/Language/Haskell/Homplexity/Comments.hs b/Language/Haskell/Homplexity/Comments.hs
--- a/Language/Haskell/Homplexity/Comments.hs
+++ b/Language/Haskell/Homplexity/Comments.hs
@@ -51,13 +51,6 @@
   Just '*' -> CommentsInside -- since it comments out the group of declarations, it belongs to the containing object
   _        -> CommentsInside
 
--- * Tests for comments
-prop_commentsAfter, prop_commentsBefore, prop_commentsGroup, prop_commentsInside :: Bool
-prop_commentsAfter  = findCommentType "  |" == CommentsAfter
-prop_commentsBefore = findCommentType "  ^" == CommentsBefore
-prop_commentsGroup  = findCommentType "  *" == CommentsInside
-prop_commentsInside = findCommentType "  a" == CommentsInside
-
 -- * Finding ranges of all commentable entities.
 -- | Tagging of source range for each commentable object.
 data CommentSite = CommentSite { siteName  :: String
diff --git a/Language/Haskell/Homplexity/Message.hs b/Language/Haskell/Homplexity/Message.hs
--- a/Language/Haskell/Homplexity/Message.hs
+++ b/Language/Haskell/Homplexity/Message.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE RecordWildCards            #-}
 {-# LANGUAGE TemplateHaskell            #-}
+-- | Classifying messages by severity and filtering them.
 module Language.Haskell.Homplexity.Message (
     Log
   , Message
diff --git a/Language/Haskell/Homplexity/Metric.hs b/Language/Haskell/Homplexity/Metric.hs
--- a/Language/Haskell/Homplexity/Metric.hs
+++ b/Language/Haskell/Homplexity/Metric.hs
@@ -1,7 +1,8 @@
 {-# LANGUAGE FlexibleInstances     #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE ScopedTypeVariables   #-}
+{-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+-- | Class for defining code metrics, and its simplest implementation - number of lines of code. 
 module Language.Haskell.Homplexity.Metric (
     Metric (..)
   , LOC
@@ -19,7 +20,6 @@
 import Language.Haskell.Exts.Syntax
 
 import Language.Haskell.Homplexity.CodeFragment
-
 
 -- | Metric can be computed on a set of @CodeFragment@ fragments
 -- and then shown.
diff --git a/Language/Haskell/Homplexity/TypeComplexity.hs b/Language/Haskell/Homplexity/TypeComplexity.hs
--- a/Language/Haskell/Homplexity/TypeComplexity.hs
+++ b/Language/Haskell/Homplexity/TypeComplexity.hs
@@ -39,7 +39,7 @@
 
 -- | Function computing constructor depth of a @Type@.
 conDepth :: Type -> Int
-conDepth con = deeper con + maxOf conDepth (childrenBi con)
+conDepth con = deeper con + maxOf conDepth (filter (/= con) $ childrenBi con)
 
 -- | Check whether given constructor of @Type@ counts in constructor depth computation.
 deeper :: Type -> Int
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,9 @@
 Changelog
 =========
+    0.4.3.0  Jun 2015
+
+        * Thanks to Mikolaj Konarski for fixing an embarrassing eternal loop due to biplate quirk.
+
     0.4.2.0  Jun 2015
 
         * Compatible with GHC 7.8.
diff --git a/homplexity.cabal b/homplexity.cabal
--- a/homplexity.cabal
+++ b/homplexity.cabal
@@ -1,5 +1,5 @@
 name:                homplexity
-version:             0.4.2.0
+version:             0.4.3.0
 synopsis:            Haskell code quality tool
 description:         Homplexity aims to measure code complexity,
                      warning about fragments that might have higher defect probability
@@ -22,7 +22,7 @@
 extra-source-files:  README.md changelog.md
 cabal-version:       >=1.10
 bug-reports:         https://github.com/mgajda/homplexity/issues
-tested-with:         GHC==7.10.1
+tested-with:         GHC==7.10.1,GHC==7.8.4
 
 source-repository head
   type:     git
@@ -69,4 +69,15 @@
   build-tools:         happy            >= 1.19.0
   -- hs-source-dirs:      
   default-language:    Haskell2010
+
+test-suite Comments
+  main-is:          tests/Comments.hs
+  other-modules:    Language.Haskell.Homplexity.CodeFragment
+                    Language.Haskell.Homplexity.Comments
+                    Language.Haskell.Homplexity.SrcSlice
+  type:             exitcode-stdio-1.0
+  build-depends:    base             >=4.5  && <4.9,
+                    haskell-src-exts >=1.12 && <1.17,
+                    uniplate         >=1.4  && <1.7
+  default-language: Haskell2010
 
diff --git a/tests/Comments.hs b/tests/Comments.hs
new file mode 100644
--- /dev/null
+++ b/tests/Comments.hs
@@ -0,0 +1,38 @@
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE ScopedTypeVariables   #-}
+{-# LANGUAGE UndecidableInstances  #-}
+module Main (
+    main 
+  ) where
+
+import Data.Char
+import Data.List
+import Control.Exception as E
+
+import Language.Haskell.Exts.SrcLoc
+import Language.Haskell.Exts
+
+import Language.Haskell.Homplexity.Comments
+
+-- * Tests for comments
+prop_commentsAfter ::  Bool
+prop_commentsAfter  = findCommentType "  |" == CommentsAfter
+
+prop_commentsBefore ::  Bool
+prop_commentsBefore = findCommentType "  ^" == CommentsBefore
+
+prop_commentsGroup ::  Bool
+prop_commentsGroup  = findCommentType "  *" == CommentsInside
+
+prop_commentsInside ::  Bool
+prop_commentsInside = findCommentType "  a" == CommentsInside
+
+-- Runs all unit tests.
+main :: IO ()
+main  = assert (and [prop_commentsAfter
+                    ,prop_commentsBefore
+                    ,prop_commentsGroup
+                    ,prop_commentsInside]) $
+          return ()