From: simonmar <unknown>
Date: Wed, 27 Feb 2002 15:16:53 +0000 (+0000)
Subject: [project @ 2002-02-27 15:16:53 by simonmar]
X-Git-Tag: Approx_11550_changesets_converted~2341
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=205d1bb04ef62a2d67aa5f3750449c50badc284b;p=ghc-hetmet.git

[project @ 2002-02-27 15:16:53 by simonmar]
When searching for files with multiple extensions in multiple paths,
search each path for all the possible files, rather than the other way
around.  Otherwise, a .hs file later in the path may override a .lhs
file earlier in the path, and similar strange things happen with
mkdependHS.

Reported-by: Duncan Coutts <duncan.coutts@worcester.oxford.ac.uk>

MERGE TO STABLE
---

diff --git a/ghc/compiler/main/Finder.lhs b/ghc/compiler/main/Finder.lhs
index de9b760..fc945b6 100644
--- a/ghc/compiler/main/Finder.lhs
+++ b/ghc/compiler/main/Finder.lhs
@@ -186,25 +186,18 @@ searchPathExts :: [FilePath]
 	       -> String
 	       -> [(String, FilePath -> String -> IO (Module, ModuleLocation))] 
 	       -> IO (Maybe (Module, ModuleLocation))
-searchPathExts path basename exts = search exts
+searchPathExts path basename exts = search path
   where
-    search         [] = return Nothing
-    search ((x,f):xs) = do
-        let fName = (basename ++ '.':x)
-        found <- findOnPath path fName
-        case found of
-   	    -- special case to avoid getting "./foo.<ext>" all the time
-	  Just "."  -> fmap Just (f fName basename)
-	  Just path -> fmap Just (f (path ++ '/':fName)
-	  		                  (path ++ '/':basename))
-	  Nothing   -> search xs
-
-findOnPath :: [String] -> String -> IO (Maybe FilePath)
-findOnPath path s = loop path
- where
-  loop [] = return Nothing
-  loop (d:ds) = do
-    let file = d ++ '/':s
-    b <- doesFileExist file
-    if b then return (Just d) else loop ds
+    search [] = return Nothing
+    search (p:ps) = loop exts
+      where	
+	base | p == "."  = basename
+	     | otherwise = p ++ '/':basename
+
+	loop [] = search ps
+	loop ((ext,fn):exts) = do
+	    let file = base ++ '.':ext
+	    b <- doesFileExist file
+	    if b then Just `liftM` fn file base
+		 else loop exts
 \end{code}