added another system.open; bugfix: koch clean may not break .git dirs anymore

koch.nim

@@ -180,7 +180,7 @@ proc cleanAux(dir: string) =
       of "nimcache": 
         echo "removing dir: ", path
         removeDir(path)
-      of "dist", ".bzr":
+      of "dist", ".git":
         nil
       else:
         cleanAux(path)

lib/system.nim

@@ -1477,9 +1477,7 @@ when not defined(EcmaScript) and not defined(NimrodVM):
     ## Opens a file named `filename` with given `mode`.
     ##
     ## Default mode is readonly. Returns true iff the file could be opened.
-    ## This throws no exception if the file could not be opened. The reason is
+    ## This throws no exception if the file could not be opened.
-    ## that the programmer needs to provide an appropriate error message 
-    ## anyway.
 
   proc Open*(f: var TFile, filehandle: TFileHandle,
              mode: TFileMode = fmRead): Bool
@@ -1487,6 +1485,15 @@ when not defined(EcmaScript) and not defined(NimrodVM):
     ##
     ## Default mode is readonly. Returns true iff the file could be opened.
     
+  proc Open*(filename: string,
+             mode: TFileMode = fmRead, bufSize: int = -1): TFile = 
+    ## Opens a file named `filename` with given `mode`.
+    ##
+    ## Default mode is readonly. Raises an ``IO`` exception if the file
+    ## could not be opened.
+    if not open(result, filename, mode, bufSize):
+      raise newException(EIO, "cannot open: " & filename)
+
   proc reopen*(f: TFile, filename: string, mode: TFileMode = fmRead): bool
     ## reopens the file `f` with given `filename` and `mode`. This 
     ## is often used to redirect the `stdin`, `stdout` or `stderr`
@@ -1582,10 +1589,7 @@ when not defined(EcmaScript) and not defined(NimrodVM):
   iterator lines*(filename: string): string =
     ## Iterate over any line in the file named `filename`.
     ## If the file does not exist `EIO` is raised.
-    var
+    var f = open(filename)
-      f: TFile
-    if not open(f, filename):
-      raise newException(EIO, "cannot open: " & filename)
     var res = ""
     while not endOfFile(f):
       rawReadLine(f, res)

todo.txt

@@ -1,3 +1,4 @@
+- clean up the tests!
 - thread support: threadvar on Windows seems broken; 
   add --deadlock_prevention:on|off switch
 - built-in serialization

web/news.txt

@@ -67,7 +67,8 @@ Additions
 - The *interactive mode* (REPL) has been improved and documented for the 
   first time.
 - Added the ``linearScanEnd``, ``unroll``, ``shallow`` pragmas.
-- Added ``system.reset``.
+- Added ``system.reset`` and a version of ``system.open`` that 
+  returns a ``TFile`` and raises an exception in case of an error.
 - The compiler now might use a hashing for string case statements depending
   on the number of string literals in the case statement.