4 files changed, 31 insertions, 36 deletions
diff --git a/lib/impure/re.nim b/lib/impure/re.nim
index ccc13248a..eaa712f01 100755
--- a/lib/impure/re.nim
+++ b/lib/impure/re.nim
@@ -342,18 +342,10 @@ proc parallelReplace*(s: string, subs: openArray[
 proc transformFile*(infile, outfile: string,
                     subs: openArray[tuple[pattern: TRegEx, repl: string]]) =
   ## reads in the file `infile`, performs a parallel replacement (calls
-  ## `parallelReplace`) and writes back to `outfile`. Calls ``quit`` if an
+  ## `parallelReplace`) and writes back to `outfile`. Raises ``EIO`` if an
   ## error occurs. This is supposed to be used for quick scripting.
   var x = readFile(infile)
-  if not isNil(x):
-    var f: TFile
-    if open(f, outfile, fmWrite):
-      write(f, x.parallelReplace(subs))
-      close(f)
-    else:
-      quit("cannot open for writing: " & outfile)
-  else:
-    quit("cannot open for reading: " & infile)
+  writeFile(outfile, x.parallelReplace(subs))
   
 iterator split*(s: string, sep: TRegEx): string =
   ## Splits the string `s` into substrings.
diff --git a/lib/pure/pegs.nim b/lib/pure/pegs.nim
index 988e510e3..b7469f65b 100755
--- a/lib/pure/pegs.nim
+++ b/lib/pure/pegs.nim
@@ -947,18 +947,10 @@ proc transformFile*(infile, outfile: string,
                     subs: openArray[tuple[pattern: TPeg, repl: string]]) {.
                     rtl, extern: "npegs$1".} =
   ## reads in the file `infile`, performs a parallel replacement (calls
-  ## `parallelReplace`) and writes back to `outfile`. Calls ``quit`` if an
+  ## `parallelReplace`) and writes back to `outfile`. Raises ``EIO`` if an
   ## error occurs. This is supposed to be used for quick scripting.
   var x = readFile(infile)
-  if not isNil(x):
-    var f: TFile
-    if open(f, outfile, fmWrite):
-      write(f, x.parallelReplace(subs))
-      close(f)
-    else:
-      quit("cannot open for writing: " & outfile)
-  else:
-    quit("cannot open for reading: " & infile)
+  writeFile(outfile, x.parallelReplace(subs))
   
 iterator split*(s: string, sep: TPeg): string =
   ## Splits the string `s` into substrings.
diff --git a/lib/system.nim b/lib/system.nim
index 7670288fc..1837959c7 100755
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -1582,10 +1582,15 @@ when not defined(EcmaScript) and not defined(NimrodVM):
     ## Flushes `f`'s buffer.
 
   proc readFile*(filename: string): string
-    ## Opens a file name `filename` for reading. Then reads the
+    ## Opens a file named `filename` for reading. Then reads the
     ## file's content completely into a string and
-    ## closes the file afterwards. Returns the string. Returns nil if there was
-    ## an error. Does not throw an IO exception.
+    ## closes the file afterwards. Returns the string. 
+    ## Raises an IO exception in case of an error.
+
+  proc writeFile*(filename, content: string)
+    ## Opens a file named `filename` for writing. Then writes the
+    ## `content` completely to the file and closes the file afterwards.
+    ## Raises an IO exception in case of an error.
 
   proc write*(f: TFile, r: float)
   proc write*(f: TFile, i: int)
diff --git a/lib/system/sysio.nim b/lib/system/sysio.nim
index 80d9b1495..af6ba49b2 100755
--- a/lib/system/sysio.nim
+++ b/lib/system/sysio.nim
@@ -78,20 +78,26 @@ proc write(f: TFile, a: openArray[string]) =
 
 #{.error: "for debugging.".}
 
+proc raiseEIO(msg: string) {.noinline, noreturn.} =
+  raise newException(EIO, msg)
+
 proc readFile(filename: string): string =
-  var f: TFile
+  var f = open(filename)
   try:
-    if open(f, filename):
-      var len = getFileSize(f)
-      if len < high(int):
-        result = newString(int(len))
-        if readBuffer(f, addr(result[0]), int(len)) != len:
-          result = nil
-      close(f)
+    var len = getFileSize(f)
+    if len < high(int):
+      result = newString(int(len))
+      if readBuffer(f, addr(result[0]), int(len)) != len:
+        raiseEIO("error while reading from file")
     else:
-      result = nil
+      raiseEIO("file too big to fit in memory")
   except EIO:
-    result = nil
+    close(f)
+
+proc writeFile(filename, content: string) =
+  var f = open(filename, fmWrite)
+  f.write(content)
+  close(f)
 
 proc EndOfFile(f: TFile): bool =
   # do not blame me; blame the ANSI C standard this is so brain-damaged
@@ -173,15 +179,15 @@ proc writeBuffer(f: TFile, buffer: pointer, len: int): int =
 
 proc write(f: TFile, s: string) =
   if writeBuffer(f, cstring(s), s.len) != s.len:
-    raise newException(EIO, "cannot write string to file")
+    raiseEIO("cannot write string to file")
 
 proc setFilePos(f: TFile, pos: int64) =
   if fseek(f, clong(pos), 0) != 0:
-    raise newException(EIO, "cannot set file position")
+    raiseEIO("cannot set file position")
 
 proc getFilePos(f: TFile): int64 =
   result = ftell(f)
-  if result < 0: raise newException(EIO, "cannot retrieve file position")
+  if result < 0: raiseEIO("cannot retrieve file position")
 
 proc getFileSize(f: TFile): int64 =
   var oldPos = getFilePos(f)