From f0fb4c496b89530f74f4ad17612383563511a27b Mon Sep 17 00:00:00 2001
From: fiddlosopher <fiddlosopher@788f1e2b-df1e-0410-8736-df70ead52e1b>
Date: Sat, 21 Jul 2007 21:34:13 +0000
Subject: [PATCH] Changes to functions for character escaping: + Removed
escapeCharAsString + Added escapeStringUsing + Changed backslashEscape to
backslashEscapes, which now returns an association list of escapes to be
passed to escapeStringUsing
git-svn-id: https://pandoc.googlecode.com/svn/trunk@748 788f1e2b-df1e-0410-8736-df70ead52e1b
---
src/Text/Pandoc/Shared.hs | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 737282b97..06c1b89c3 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -35,8 +35,8 @@ module Text.Pandoc.Shared (
-- * Text processing
joinWithSep,
tabsToSpaces,
- backslashEscape,
- escapeCharAsString,
+ backslashEscapes,
+ escapeStringUsing,
endsWith,
stripTrailingNewlines,
removeLeadingTrailingSpace,
@@ -260,22 +260,21 @@ tabsInLine num tabstop (c:cs) =
else nextnumraw in
replacement ++ (tabsInLine nextnum tabstop cs)
--- | Escape designated characters with backslash.
-backslashEscape :: [Char] -- ^ list of special characters to escape
- -> String -- ^ string input
- -> String
-backslashEscape special [] = []
-backslashEscape special (x:xs) = if x `elem` special
- then '\\':x:(backslashEscape special xs)
- else x:(backslashEscape special xs)
+-- | Returns an association list of backslash escapes for the
+-- designated characters.
+backslashEscapes :: [Char] -- ^ list of special characters to escape
+ -> [(Char, String)]
+backslashEscapes = map (\ch -> (ch, ['\\',ch]))
--- | Escape a character as a string
-escapeCharAsString ch str "" = ""
-escapeCharAsString ch str (x:xs) | x == ch =
- str ++ escapeCharAsString ch str xs
-escapeCharAsString ch str xs =
- let (a,b) = break (== ch) xs in
- a ++ escapeCharAsString ch str b
+-- | Escape a string of characters, using an association list of
+-- characters and strings.
+escapeStringUsing :: [(Char, String)] -> String -> String
+escapeStringUsing escapeTable "" = ""
+escapeStringUsing escapeTable (x:xs) =
+ case (lookup x escapeTable) of
+ Just str -> str ++ rest
+ Nothing -> x:rest
+ where rest = escapeStringUsing escapeTable xs
-- | Returns @True@ if string ends with given character.
endsWith :: Char -> [Char] -> Bool