From 7b54ec9006d5a9dfe61e50eeee7555ca845549eb Mon Sep 17 00:00:00 2001
From: Stefan Dresselhaus <sdressel@techfak.uni-bielefeld.de>
Date: Tue, 15 Apr 2014 07:17:45 +0200
Subject: [PATCH] improved Parser and added documentation

---
 src/Importer/IQM/Parser.hs | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/Importer/IQM/Parser.hs b/src/Importer/IQM/Parser.hs
index 932d0a2..29fc148 100644
--- a/src/Importer/IQM/Parser.hs
+++ b/src/Importer/IQM/Parser.hs
@@ -135,16 +135,23 @@ readMeshes n = do
 
 infix 5 .-
 
+skipToCounter :: Integral a => a -> CParser ()
+skipToCounter a = do
+                        let d = fromIntegral a
+			c <- get
+                        when (d < c) $ fail "wanting to skip to counter already passed"
+			_ <- lift $ take $ d .- c
+			put d
+
 parseIQM :: CParser IQM
 parseIQM = do
-        put 0
-        h <- readHeader
-	soFar <- get
-        _ <- lift $ take $ ofs_text h .- soFar
-        text <- lift $ take $ fromIntegral $ num_text h
-        soFar <- get
-        _ <- lift $ take $ ofs_meshes h .- soFar
-        meshes' <- readMeshes (fromIntegral (num_meshes h))
+        put 0 							--start at offset 0
+        h <- readHeader						--read header
+        skipToCounter $ ofs_text h				--skip 0-n bytes to get to text
+        text <- lift . take . fromIntegral $ num_text h         --read texts
+	modify . (+) . fromIntegral $ num_text h                --put offset forward
+        skipToCounter $ ofs_meshes h                            --skip 0-n bytes to get to meshes
+        meshes' <- readMeshes (fromIntegral (num_meshes h))     --read meshes
         return IQM
                 { header = h
                 , texts = filter (not.null) (split (unsafeCoerce '\0') text)