From 8fdf8c1d4cf33972a5fef7bf8dcf75478733da8c Mon Sep 17 00:00:00 2001
From: fiddlosopher <fiddlosopher@788f1e2b-df1e-0410-8736-df70ead52e1b>
Date: Tue, 28 Aug 2007 19:33:47 +0000
Subject: [PATCH] + Removed tabsToSpaces and tabsInLine from
 Text.Pandoc.Shared.   (They were used only in Main.) + Wrote new
 tabsToSpacesInLine function in Main that changes tabs   to spaces and removes
 DOS line-endings in one pass, for a slight   speed improvement.

git-svn-id: https://pandoc.googlecode.com/svn/trunk@942 788f1e2b-df1e-0410-8736-df70ead52e1b
---
 src/Main.hs               | 18 ++++++++++++++----
 src/Text/Pandoc/Shared.hs | 22 ----------------------
 2 files changed, 14 insertions(+), 26 deletions(-)

diff --git a/src/Main.hs b/src/Main.hs
index b1aa55982..4bd3982d2 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -31,7 +31,7 @@ writers.
 module Main where
 import Text.Pandoc
 import Text.Pandoc.UTF8
-import Text.Pandoc.Shared ( joinWithSep, tabsToSpaces )
+import Text.Pandoc.Shared ( joinWithSep )
 import Text.Regex ( mkRegex, matchRegex )
 import System.Environment ( getArgs, getProgName, getEnvironment )
 import System.Exit ( exitWith, ExitCode (..) )
@@ -445,8 +445,18 @@ main = do
                  Just cols -> read cols
                  Nothing   -> stateColumns defaultParserState
 
-  let tabFilter = if preserveTabs then id else (tabsToSpaces tabStop)
-  let removeCRs str = filter (/= '\r') str  -- remove DOS-style line endings
+  let tabsToSpacesInLine _ [] = ""
+      tabsToSpacesInLine _ ('\r':[]) = ""  -- remove DOS line-endings
+      tabsToSpacesInLine spsToNextStop (x:xs) = 
+         if x == '\t'
+            then if preserveTabs
+                    then x:(tabsToSpacesInLine tabStop xs) 
+                    else replicate spsToNextStop ' ' ++ 
+                         tabsToSpacesInLine tabStop xs 
+            else x:(tabsToSpacesInLine (spsToNextStop - 1) xs)
+
+  let tabFilter = unlines . map (tabsToSpacesInLine tabStop) . lines
+
   let startParserState = 
          defaultParserState { stateParseRaw    = parseRaw,
                               stateTabStop     = tabStop, 
@@ -484,7 +494,7 @@ main = do
   (readSources sources) >>= (hPutStrLn output . toUTF8 . 
                              (writer writerOptions) . 
                              (reader startParserState) .  tabFilter .
-                             removeCRs .  fromUTF8 .  (joinWithSep "\n")) >> 
+                             fromUTF8 .  (joinWithSep "\n")) >> 
                              hClose output
 
   where 
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 2958b4388..ddc325374 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -34,7 +34,6 @@ module Text.Pandoc.Shared (
                      substitute,
                      joinWithSep,
                      -- * Text processing
-                     tabsToSpaces,
                      backslashEscapes,
                      escapeStringUsing,
                      stripTrailingNewlines,
@@ -143,27 +142,6 @@ joinWithSep sep lst = foldr1 (\a b -> a ++ sep ++ b) lst
 -- Text processing
 --
 
--- | Convert tabs to spaces (with adjustable tab stop).
-tabsToSpaces :: Int     -- ^ Tabstop
-             -> String  -- ^ String to convert
-             -> String
-tabsToSpaces tabstop str =
-  unlines $ map (tabsInLine tabstop tabstop) (lines str)
-
--- | Convert tabs to spaces in one line.
-tabsInLine :: Int      -- ^ Number of spaces to next tab stop
-           -> Int      -- ^ Tabstop
-           -> String   -- ^ Line to convert
-           -> String
-tabsInLine num tabstop [] = ""
-tabsInLine num tabstop (c:cs) = 
-  let (replacement, nextnum) = if c == '\t'
-                                  then (replicate num ' ', tabstop)
-                                  else if num > 1
-                                          then ([c], num - 1)
-                                          else ([c], tabstop)
-  in  replacement ++ tabsInLine nextnum tabstop cs
-
 -- | Returns an association list of backslash escapes for the
 -- designated characters.
 backslashEscapes :: [Char]    -- ^ list of special characters to escape