better streams implemenation; fixes #63

lib/impure/zipfiles.nim

@@ -75,10 +75,10 @@ proc mySourceCallback(state, data: pointer, len: int,
   var src = cast[PStream](state)
   case cmd
   of ZIP_SOURCE_OPEN: 
-    if src.setPosition != nil: src.setPosition(src, 0) # reset
+    if src.setPositionImpl != nil: setPosition(src, 0) # reset
   of ZIP_SOURCE_READ:
-    result = src.readData(src, data, len)
+    result = readData(src, data, len)
-  of ZIP_SOURCE_CLOSE: src.close(src)
+  of ZIP_SOURCE_CLOSE: close(src)
   of ZIP_SOURCE_STAT: 
     var stat = cast[PZipStat](data)
     zip_stat_init(stat)
@@ -120,8 +120,8 @@ proc fsReadData(s: PStream, buffer: pointer, bufLen: int): int =
 proc newZipFileStream(f: PZipFile): PZipFileStream = 
   new(result)
   result.f = f
-  result.close = fsClose
+  result.closeImpl = fsClose
-  result.readData = fsReadData
+  result.readDataImpl = fsReadData
   # other methods are nil!
 
 # ----------------------------------------------------------------------------

lib/pure/osproc.nim

@@ -171,7 +171,7 @@ proc execProcesses*(cmds: openArray[string],
         when defined(debugExecProcesses):
           var err = ""
           var outp = outputStream(q[r])
-          while running(q[r]) or not outp.atEnd(outp):
+          while running(q[r]) or not atEnd(outp):
             err.add(outp.readLine())
             err.add("\n")
           echo(err)
@@ -213,10 +213,10 @@ when not defined(useNimRtl):
     var p = startCmd(command, options=options)
     var outp = outputStream(p)
     result = TaintedString""
-    while running(p) or not outp.atEnd(outp):
+    while running(p) or not atEnd(outp):
       result.string.add(outp.readLine().string)
       result.string.add("\n")
-    outp.close(outp)
+    close(outp)
     close(p)
 
 when false:
@@ -259,10 +259,10 @@ when defined(Windows) and not defined(useNimRtl):
   proc newFileHandleStream(handle: THandle): PFileHandleStream =
     new(result)
     result.handle = handle
-    result.close = hsClose
+    result.closeImpl = hsClose
-    result.atEnd = hsAtEnd
+    result.atEndImpl = hsAtEnd
-    result.readData = hsReadData
+    result.readDataImpl = hsReadData
-    result.writeData = hsWriteData
+    result.writeDataImpl = hsWriteData
 
   proc buildCommandLine(a: string, args: openarray[string]): cstring =
     var res = quoteIfContainsWhite(a)
@@ -643,10 +643,10 @@ proc execCmdEx*(command: string, options: set[TProcessOption] = {
   result = (TaintedString"", -1)
   while true:
     if result[1] == -1: result[1] = peekExitCode(p)
-    if result[1] != -1 and outp.atEnd(outp): break
+    if result[1] != -1 and atEnd(outp): break
     result[0].string.add(outp.readLine().string)
     result[0].string.add("\n")
-  outp.close(outp)
+  close(outp)
   close(p)
 
 

lib/pure/streams.nim

@@ -19,13 +19,75 @@ proc newEIO(msg: string): ref EIO =
 type
   PStream* = ref TStream
   TStream* = object of TObject ## Stream interface that supports
-                               ## writing or reading.
+                               ## writing or reading. Note that these fields
-    close*: proc (s: PStream)
+                               ## here shouldn't be used directly. They are
-    atEnd*: proc (s: PStream): bool
+                               ## accessible so that a stream implementation
-    setPosition*: proc (s: PStream, pos: int)
+                               ## can override them.
-    getPosition*: proc (s: PStream): int
+    closeImpl*: proc (s: PStream)
-    readData*: proc (s: PStream, buffer: pointer, bufLen: int): int
+    atEndImpl*: proc (s: PStream): bool
-    writeData*: proc (s: PStream, buffer: pointer, bufLen: int)
+    setPositionImpl*: proc (s: PStream, pos: int)
+    getPositionImpl*: proc (s: PStream): int
+    readDataImpl*: proc (s: PStream, buffer: pointer, bufLen: int): int
+    writeDataImpl*: proc (s: PStream, buffer: pointer, bufLen: int)
+    flushImpl*: proc (s: PStream)
+
+proc flush*(s: PStream) =
+  ## flushes the buffers that the stream `s` might use.
+  if not isNil(s.flushImpl): s.flushImpl(s)
+
+proc close*(s: PStream) =
+  ## closes the stream `s`.
+  if not isNil(s.closeImpl): s.closeImpl(s)
+
+proc close*(s, unused: PStream) {.deprecated.} =
+  ## closes the stream `s`.
+  s.closeImpl(s)
+
+proc atEnd*(s: PStream): bool =
+  ## checks if more data can be read from `f`. Returns true if all data has
+  ## been read.
+  result = s.atEndImpl(s)
+
+proc atEnd*(s, unused: PStream): bool {.deprecated.} =
+  ## checks if more data can be read from `f`. Returns true if all data has
+  ## been read.
+  result = s.atEndImpl(s)
+
+proc setPosition*(s: PStream, pos: int) =
+  ## sets the position `pos` of the stream `s`.
+  s.setPositionImpl(s, pos)
+
+proc setPosition*(s, unused: PStream, pos: int) {.deprecated.} =
+  ## sets the position `pos` of the stream `s`.
+  s.setPositionImpl(s, pos)
+
+proc getPosition*(s: PStream): int =
+  ## retrieves the current position in the stream `s`.
+  result = s.getPositionImpl(s)
+
+proc getPosition*(s, unused: PStream): int {.deprecated.} =
+  ## retrieves the current position in the stream `s`.
+  result = s.getPositionImpl(s)
+
+proc readData*(s: PStream, buffer: pointer, bufLen: int): int =
+  ## low level proc that reads data into an untyped `buffer` of `bufLen` size.
+  result = s.readDataImpl(s, buffer, bufLen)
+
+proc readData*(s, unused: PStream, buffer: pointer, 
+               bufLen: int): int {.deprecated.} =
+  ## low level proc that reads data into an untyped `buffer` of `bufLen` size.
+  result = s.readDataImpl(s, buffer, bufLen)
+
+proc writeData*(s: PStream, buffer: pointer, bufLen: int) =
+  ## low level proc that writes an untyped `buffer` of `bufLen` size
+  ## to the stream `s`.
+  s.writeDataImpl(s, buffer, bufLen)
+
+proc writeData*(s, unused: PStream, buffer: pointer, 
+                bufLen: int) {.deprecated.} =
+  ## low level proc that writes an untyped `buffer` of `bufLen` size
+  ## to the stream `s`.
+  s.writeDataImpl(s, buffer, bufLen)
 
 proc write*[T](s: PStream, x: T) = 
   ## generic write procedure. Writes `x` to the stream `s`. Implementation:
@@ -35,22 +97,22 @@ proc write*[T](s: PStream, x: T) =
   ##     s.writeData(s, addr(x), sizeof(x))
   var y: T
   shallowCopy(y, x)
-  s.writeData(s, addr(y), sizeof(y))
+  writeData(s, addr(y), sizeof(y))
 
 proc write*(s: PStream, x: string) = 
   ## writes the string `x` to the the stream `s`. No length field or 
   ## terminating zero is written.
-  s.writeData(s, cstring(x), x.len)
+  writeData(s, cstring(x), x.len)
 
 proc read[T](s: PStream, result: var T) = 
   ## generic read procedure. Reads `result` from the stream `s`.
-  if s.readData(s, addr(result), sizeof(T)) != sizeof(T):
+  if readData(s, addr(result), sizeof(T)) != sizeof(T):
     raise newEIO("cannot read from stream")
 
 proc readChar*(s: PStream): char =
   ## reads a char from the stream `s`. Raises `EIO` if an error occured.
   ## Returns '\0' as an EOF marker.
-  discard s.readData(s, addr(result), sizeof(result))
+  discard readData(s, addr(result), sizeof(result))
 
 proc readBool*(s: PStream): bool = 
   ## reads a bool from the stream `s`. Raises `EIO` if an error occured.
@@ -84,14 +146,14 @@ proc readStr*(s: PStream, length: int): TaintedString =
   ## reads a string of length `length` from the stream `s`. Raises `EIO` if 
   ## an error occured.
   result = newString(length).TaintedString
-  var L = s.readData(s, addr(string(result)[0]), length)
+  var L = readData(s, addr(string(result)[0]), length)
   if L != length: setLen(result.string, L)
 
 proc readLine*(s: PStream): TaintedString =
   ## Reads a line from a stream `s`. Note: This is not very efficient. Raises 
   ## `EIO` if an error occured.
   result = TaintedString""
-  while not s.atEnd(s): 
+  while not atEnd(s): 
     var c = readChar(s)
     if c == '\c': 
       c = readChar(s)
@@ -140,12 +202,12 @@ proc newStringStream*(s: string = ""): PStringStream =
   new(result)
   result.data = s
   result.pos = 0
-  result.close = ssClose
+  result.closeImpl = ssClose
-  result.atEnd = ssAtEnd
+  result.atEndImpl = ssAtEnd
-  result.setPosition = ssSetPosition
+  result.setPositionImpl = ssSetPosition
-  result.getPosition = ssGetPosition
+  result.getPositionImpl = ssGetPosition
-  result.readData = ssReadData
+  result.readDataImpl = ssReadData
-  result.writeData = ssWriteData
+  result.writeDataImpl = ssWriteData
 
 type
   PFileStream* = ref TFileStream ## a stream that encapsulates a `TFile`
@@ -153,6 +215,7 @@ type
     f: TFile
 
 proc fsClose(s: PStream) = close(PFileStream(s).f)
+proc fsFlush(s: PStream) = flushFile(PFileStream(s).f)
 proc fsAtEnd(s: PStream): bool = return EndOfFile(PFileStream(s).f)
 proc fsSetPosition(s: PStream, pos: int) = setFilePos(PFileStream(s).f, pos)
 proc fsGetPosition(s: PStream): int = return int(getFilePos(PFileStream(s).f))
@@ -168,12 +231,13 @@ proc newFileStream*(f: TFile): PFileStream =
   ## creates a new stream from the file `f`.
   new(result)
   result.f = f
-  result.close = fsClose
+  result.closeImpl = fsClose
-  result.atEnd = fsAtEnd
+  result.atEndImpl = fsAtEnd
-  result.setPosition = fsSetPosition
+  result.setPositionImpl = fsSetPosition
-  result.getPosition = fsGetPosition
+  result.getPositionImpl = fsGetPosition
-  result.readData = fsReadData
+  result.readDataImpl = fsReadData
-  result.writeData = fsWriteData
+  result.writeDataImpl = fsWriteData
+  result.flushImpl = fsFlush
 
 proc newFileStream*(filename: string, mode: TFileMode): PFileStream = 
   ## creates a new stream from the file named `filename` with the mode `mode`.

lib/system.nim

@@ -2040,23 +2040,23 @@ proc `+=`*[T](x, y: ordinal[T]) {.magic: "Inc", noSideEffect.}
 proc `-=`*[T](x, y: ordinal[T]) {.magic: "Dec", noSideEffect.}
   ## Decrements an ordinal
 
-proc `*=`*[T](x: var ordinal[T], y: ordinal[T]) {.inline noSideEffect.} =
+proc `*=`*[T](x: var ordinal[T], y: ordinal[T]) {.inline, noSideEffect.} =
-  ## Binary `*=` operator for oridinals
+  ## Binary `*=` operator for ordinals
   x = x * y
 
-proc `+=` *(x: var float, y:float) {.inline noSideEffect.} =
+proc `+=` *(x: var float, y:float) {.inline, noSideEffect.} =
   ## Increments in placee a floating point number
   x = x + y
 
-proc `-=` *(x: var float, y:float) {.inline noSideEffect.} =
+proc `-=` *(x: var float, y:float) {.inline, noSideEffect.} =
   ## Decrements in place a floating point number
   x = x - y
 
-proc `*=` *(x: var float, y:float) {.inline noSideEffect.} =
+proc `*=` *(x: var float, y:float) {.inline, noSideEffect.} =
   ## Multiplies in place a floating point number
   x = x * y
 
-proc `/=` *(x: var float, y:float) {.inline noSideEffect.} =
+proc `/=` *(x: var float, y:float) {.inline, noSideEffect.} =
   ## Divides in place a floating point number
   x = x / y
 

web/news.txt

@@ -46,6 +46,9 @@ Changes affecting backwards compatibility
   ``os.removeDir``.
 - Operators now have diffent precedence rules: Assignment-like operators 
   (like ``*=``) are now special-cased. 
+- The fields in ``TStream`` have been renamed to have an ``Impl`` suffix 
+  because they should not be used directly anymore. 
+  Wrapper procs have been created that should be used instead.
 
 
 Language Additions