Improve documentation

hpath/src/HPath.hs

@@ -31,7 +31,7 @@ module HPath
   -- * PatternSynonyms/ViewPatterns
   ,pattern Path
 #endif
-   -- * Path Parsing
+   -- * Path Construction
   ,parseAbs
   ,parseRel
   ,parseAny

hpath/src/HPath/Internal.hs

@@ -10,15 +10,19 @@ import Control.DeepSeq (NFData (..))
 import Data.ByteString (ByteString)
 import Data.Data
 
+-- | The main Path type.
 --
+-- The type variable 'b' is either:
 --
+--   * Abs -- absolute path
+--   * Rel -- relative path
 --
+-- Internally is a ByteString. The path is guaranteed to
+-- be normalised and contain no trailing Path separators,
+-- except for the '/' root path.
+--
+-- There are no duplicate path separators
+-- @\/\/@, no @..@, no @.\/@, no @~\/@, etc.
 data Path b = MkPath ByteString
   deriving (Typeable)