Moved tabFilter to Shared.

Removed optPreserveTabs; instead, tabstop of 0 means preserve tabs.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1532 788f1e2b-df1e-0410-8736-df70ead52e1b

2 files changed, 26 insertions, 22 deletions

diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 6854e5ae6..13eab9bdb 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -49,6 +49,7 @@ module Text.Pandoc.Shared (
                      wrapTeXIfNeeded,
                      BlockWrapper (..),
                      wrappedBlocksToDoc,
+                     tabFilter,
                      -- * Parsing
                      (>>~),
                      anyLine,
@@ -285,6 +286,26 @@ wrappedBlocksToDoc = foldr addBlock empty
            addBlock (Pad d) accum = d $$ text "" $$ accum
            addBlock (Reg d) accum = d $$ accum
 
+-- | Convert tabs to spaces and filter out DOS line endings.
+-- Tabs will be preserved if tab stop is set to 0.
+tabFilter :: Int       -- ^ Tab stop
+          -> String    -- ^ Input
+          -> String
+tabFilter tabStop =
+  let go _ [] = ""
+      go _ ('\n':xs) = '\n' : go tabStop xs
+      go _ ('\r':'\n':xs) = '\n' : go tabStop xs
+      go _ ('\r':xs) = '\n' : go tabStop xs
+      go spsToNextStop ('\t':xs) =
+        if tabStop == 0
+           then '\t' : go tabStop xs
+           else replicate spsToNextStop ' ' ++ go tabStop xs
+      go 1 (x:xs) =
+        x : go tabStop xs
+      go spsToNextStop (x:xs) =
+        x : go (spsToNextStop - 1) xs
+  in  go tabStop
+
 --
 -- Parsing
 --
diff --git a/src/pandoc.hs b/src/pandoc.hs
index e498b3c0a..64b79619c 100644
--- a/src/pandoc.hs
+++ b/src/pandoc.hs
@@ -32,7 +32,7 @@ writers.
 module Main where
 import Text.Pandoc
 import Text.Pandoc.ODT
-import Text.Pandoc.Shared ( HTMLMathMethod (..), splitBy, ObfuscationMethod (..) )
+import Text.Pandoc.Shared ( HTMLMathMethod (..), splitBy, tabFilter, ObfuscationMethod (..) )
 import Text.Pandoc.Highlighting ( languages )
 import System.Environment ( getArgs, getProgName, getEnvironment )
 import System.Exit ( exitWith, ExitCode (..) )
@@ -131,8 +131,7 @@ writeDoc _ = prettyPandoc
 
 -- | Data structure for command line options.
 data Opt = Opt
-    { optPreserveTabs      :: Bool    -- ^ Convert tabs to spaces
-    , optTabStop           :: Int     -- ^ Number of spaces per tab
+    { optTabStop           :: Int     -- ^ Number of spaces per tab
     , optStandalone        :: Bool    -- ^ Include header, footer
     , optReader            :: String  -- ^ Reader format
     , optWriter            :: String  -- ^ Writer format
@@ -167,8 +166,7 @@ data Opt = Opt
 -- | Defaults for command-line options.
 defaultOpts :: Opt
 defaultOpts = Opt
-    { optPreserveTabs      = False
-    , optTabStop           = 4
+    { optTabStop           = 4
     , optStandalone        = False
     , optReader            = ""    -- null for default reader
     , optWriter            = ""    -- null for default writer
@@ -229,7 +227,7 @@ options =
 
     , Option "p" ["preserve-tabs"]
                  (NoArg
-                  (\opt -> return opt { optPreserveTabs = True }))
+                  (\opt -> return opt { optTabStop = 0 }))
                  "" -- "Preserve tabs instead of converting to spaces"
 
     , Option "" ["tab-stop"]
@@ -519,8 +517,7 @@ main = do
   -- thread option data structure through all supplied option actions
   opts <- foldl (>>=) (return defaultOpts') actions
 
-  let Opt    { optPreserveTabs       = preserveTabs
-              , optTabStop           = tabStop
+  let Opt    { optTabStop           = tabStop
               , optStandalone        = standalone
               , optReader            = readerName
               , optWriter            = writerName
@@ -581,20 +578,6 @@ main = do
                  Just cols -> read cols
                  Nothing   -> stateColumns defaultParserState
 
-  let tabFilter _ [] = ""
-      tabFilter _ ('\n':xs) = '\n' : tabFilter tabStop xs
-                                      -- remove DOS line endings
-      tabFilter _ ('\r':'\n':xs) = '\n' : tabFilter tabStop xs
-      tabFilter _ ('\r':xs) = '\n' : tabFilter tabStop xs
-      tabFilter spsToNextStop ('\t':xs) =
-        if preserveTabs
-           then '\t' : tabFilter tabStop xs
-           else replicate spsToNextStop ' ' ++ tabFilter tabStop xs
-      tabFilter 1 (x:xs) =
-        x : tabFilter tabStop xs
-      tabFilter spsToNextStop (x:xs) =
-        x : tabFilter (spsToNextStop - 1) xs
-
   let standalone' = (standalone && not strict) || isNonTextOutput writerName'
 
 #ifdef _CITEPROC