1 files changed, 16 insertions, 11 deletions
diff --git a/lib/system.nim b/lib/system.nim
index daf0c5423..c786e8355 100755
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -1213,14 +1213,14 @@ iterator fieldPairs*(x, y: tuple[]): tuple[a, b: expr] {.
   ## in the loop body.
 
 proc `==`*[T: tuple](x, y: T): bool = 
-  ## generic ``==`` operator that is lifted from the components
+  ## generic ``==`` operator for tuples that is lifted from the components
   ## of `x` and `y`.
   for a, b in fields(x, y):
     if a != b: return false
   return true
 
 proc `<=`*[T: tuple](x, y: T): bool = 
-  ## generic ``<=`` operator that is lifted from the components
+  ## generic ``<=`` operator for tuples that is lifted from the components
   ## of `x` and `y`. This implementation uses `cmp`.
   for a, b in fields(x, y):
     var c = cmp(a, b)
@@ -1229,7 +1229,7 @@ proc `<=`*[T: tuple](x, y: T): bool =
   return true
 
 proc `<`*[T: tuple](x, y: T): bool = 
-  ## generic ``<`` operator that is lifted from the components
+  ## generic ``<`` operator for tuples that is lifted from the components
   ## of `x` and `y`. This implementation uses `cmp`.
   for a, b in fields(x, y):
     var c = cmp(a, b)
@@ -1238,7 +1238,8 @@ proc `<`*[T: tuple](x, y: T): bool =
   return false
 
 proc `$`*[T: tuple](x: T): string = 
-  ## generic ``$`` operator that is lifted from the components of `x`.
+  ## generic ``$`` operator for tuples that is lifted from the components
+  ## of `x`.
   result = "("
   for name, value in fieldPairs(x):
     if result.len > 1: result.add(", ")
@@ -1476,15 +1477,22 @@ 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
-    ## that the programmer needs to provide an appropriate error message 
-    ## anyway.
+    ## This throws no exception if the file could not be opened.
 
   proc Open*(f: var TFile, filehandle: TFileHandle,
              mode: TFileMode = fmRead): Bool
     ## Creates a ``TFile`` from a `filehandle` with given `mode`.
     ##
     ## 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 
@@ -1581,10 +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
-      f: TFile
-    if not open(f, filename):
-      raise newException(EIO, "cannot open: " & filename)
+    var f = open(filename)
     var res = ""
     while not endOfFile(f):
       rawReadLine(f, res)