Merge branch 'devel' of https://github.com/Araq/Nimrod into devel

5 files changed, 382 insertions, 53 deletions

diff --git a/lib/pure/asyncdispatch.nim b/lib/pure/asyncdispatch.nim
index 93eddc2a6..fcf947831 100644
--- a/lib/pure/asyncdispatch.nim
+++ b/lib/pure/asyncdispatch.nim
@@ -37,10 +37,10 @@ type
   PFutureBase* = ref object of PObject
     cb: proc () {.closure,gcsafe.}
     finished: bool
+    error*: ref EBase
 
   PFuture*[T] = ref object of PFutureBase
     value: T
-    error*: ref EBase # TODO: This shouldn't be necessary, generics bug?
 
 proc newFuture*[T](): PFuture[T] =
   ## Creates a new future.
@@ -114,7 +114,7 @@ proc finished*[T](future: PFuture[T]): bool =
   ## ``True`` may indicate an error or a value. Use ``failed`` to distinguish.
   future.finished
 
-proc failed*[T](future: PFuture[T]): bool =
+proc failed*(future: PFutureBase): bool =
   ## Determines whether ``future`` completed with an error.
   future.error != nil
 
@@ -182,8 +182,9 @@ when defined(windows) or defined(nimdoc):
     var lpNumberOfBytesTransferred: DWORD
     var lpCompletionKey: ULONG
     var customOverlapped: PCustomOverlapped
-    let res = GetQueuedCompletionStatus(p.ioPort, addr lpNumberOfBytesTransferred,
-        addr lpCompletionKey, addr customOverlapped, llTimeout).bool
+    let res = GetQueuedCompletionStatus(p.ioPort,
+        addr lpNumberOfBytesTransferred, addr lpCompletionKey,
+        cast[ptr POverlapped](addr customOverlapped), llTimeout).bool
 
     # http://stackoverflow.com/a/12277264/492186
     # TODO: http://www.serverframework.com/handling-multiple-pending-socket-read-and-write-operations.html
@@ -763,38 +764,69 @@ proc accept*(socket: TAsyncFD): PFuture[TAsyncFD] =
 template createCb*(retFutureSym, iteratorNameSym: expr): stmt {.immediate.} =
   var nameIterVar = iteratorNameSym
   proc cb {.closure,gcsafe.} =
-    if not nameIterVar.finished:
-      var next = nameIterVar()
-      if next == nil:
-        assert retFutureSym.finished, "Async procedure's return Future was not finished."
-      else:
-        next.callback = cb
+    try:
+      if not nameIterVar.finished:
+        var next = nameIterVar()
+        if next == nil:
+          assert retFutureSym.finished, "Async procedure's return Future was not finished."
+        else:
+          next.callback = cb
+    except:
+      retFutureSym.fail(getCurrentException())
   cb()
 
+proc generateExceptionCheck(futSym,
+    exceptBranch, rootReceiver: PNimrodNode): PNimrodNode {.compileTime.} =
+  if exceptBranch == nil:
+    result = rootReceiver
+  else:
+    if exceptBranch[0].kind == nnkStmtList:
+      result = newIfStmt(
+        (newDotExpr(futSym, newIdentNode("failed")),
+           exceptBranch[0]
+         )
+      )
+    else:
+      expectKind(exceptBranch[1], nnkStmtList)
+      result = newIfStmt(
+        (newDotExpr(futSym, newIdentNode("failed")),
+           newIfStmt(
+             (infix(newDotExpr(futSym, newIdentNode("error")), "of", exceptBranch[0]),
+              exceptBranch[1])
+           )
+         )
+      )
+    let elseNode = newNimNode(nnkElse)
+    elseNode.add newNimNode(nnkStmtList)
+    elseNode[0].add rootReceiver
+    result.add elseNode
+
 template createVar(futSymName: string, asyncProc: PNimrodNode,
-                   valueReceiver: expr) {.immediate, dirty.} =
-  # TODO: Used template here due to bug #926
+                   valueReceiver, rootReceiver: expr) {.immediate, dirty.} =
   result = newNimNode(nnkStmtList)
   var futSym = genSym(nskVar, "future")
   result.add newVarStmt(futSym, asyncProc) # -> var future<x> = y
   result.add newNimNode(nnkYieldStmt).add(futSym) # -> yield future<x>
   valueReceiver = newDotExpr(futSym, newIdentNode("read")) # -> future<x>.read
+  result.add generateExceptionCheck(futSym, exceptBranch, rootReceiver)
 
 proc processBody(node, retFutureSym: PNimrodNode,
-                 subtypeName: string): PNimrodNode {.compileTime.} =
+                 subTypeIsVoid: bool,
+                 exceptBranch: PNimrodNode): PNimrodNode {.compileTime.} =
+  #echo(node.treeRepr)
   result = node
   case node.kind
   of nnkReturnStmt:
     result = newNimNode(nnkStmtList)
     if node[0].kind == nnkEmpty:
-      if subtypeName != "void":
+      if not subtypeIsVoid:
         result.add newCall(newIdentNode("complete"), retFutureSym,
             newIdentNode("result"))
       else:
         result.add newCall(newIdentNode("complete"), retFutureSym)
     else:
       result.add newCall(newIdentNode("complete"), retFutureSym,
-        node[0].processBody(retFutureSym, subtypeName))
+        node[0].processBody(retFutureSym, subtypeIsVoid, exceptBranch))
 
     result.add newNimNode(nnkReturnStmt).add(newNilLit())
     return # Don't process the children of this return stmt
@@ -807,16 +839,16 @@ proc processBody(node, retFutureSym: PNimrodNode,
       of nnkCall:
         # await foo(p, x)
         var futureValue: PNimrodNode
-        createVar("future" & $node[1][0].toStrLit, node[1], futureValue)
-        result.add futureValue
+        createVar("future" & $node[1][0].toStrLit, node[1], futureValue,
+                  futureValue)
       else:
         error("Invalid node kind in 'await', got: " & $node[1].kind)
     elif node[1].kind == nnkCommand and node[1][0].kind == nnkIdent and
          node[1][0].ident == !"await":
       # foo await x
       var newCommand = node
-      createVar("future" & $node[0].toStrLit, node[1][1], newCommand[1])
-      result.add newCommand
+      createVar("future" & $node[0].toStrLit, node[1][1], newCommand[1],
+                newCommand)
 
   of nnkVarSection, nnkLetSection:
     case node[0][2].kind
@@ -825,8 +857,7 @@ proc processBody(node, retFutureSym: PNimrodNode,
         # var x = await y
         var newVarSection = node # TODO: Should this use copyNimNode?
         createVar("future" & $node[0][0].ident, node[0][2][1],
-          newVarSection[0][2])
-        result.add newVarSection
+          newVarSection[0][2], newVarSection)
     else: discard
   of nnkAsgn:
     case node[1].kind
@@ -834,19 +865,43 @@ proc processBody(node, retFutureSym: PNimrodNode,
       if node[1][0].ident == !"await":
         # x = await y
         var newAsgn = node
-        createVar("future" & $node[0].toStrLit, node[1][1], newAsgn[1])
-        result.add newAsgn
+        createVar("future" & $node[0].toStrLit, node[1][1], newAsgn[1], newAsgn)
     else: discard
   of nnkDiscardStmt:
     # discard await x
-    if node[0][0].kind == nnkIdent and node[0][0].ident == !"await":
-      var dummy = newNimNode(nnkStmtList)
-      createVar("futureDiscard_" & $toStrLit(node[0][1]), node[0][1], dummy)
+    if node[0].kind != nnkEmpty and node[0][0].kind == nnkIdent and
+          node[0][0].ident == !"await":
+      var newDiscard = node
+      createVar("futureDiscard_" & $toStrLit(node[0][1]), node[0][1],
+                newDiscard[0], newDiscard)
+  of nnkTryStmt:
+    # try: await x; except: ...
+    result = newNimNode(nnkStmtList)
+    proc processForTry(n: PNimrodNode, i: var int,
+                       res: PNimrodNode): bool {.compileTime.} =
+      result = false
+      while i < n[0].len:
+        var processed = processBody(n[0][i], retFutureSym, subtypeIsVoid, n[1])
+        if processed.kind != n[0][i].kind or processed.len != n[0][i].len:
+          expectKind(processed, nnkStmtList)
+          expectKind(processed[2][1], nnkElse)
+          i.inc
+          discard processForTry(n, i, processed[2][1][0])
+          res.add processed
+          result = true
+        else:
+          res.add n[0][i]
+          i.inc
+    var i = 0
+    if not processForTry(node, i, result):
+      var temp = node
+      temp[0] = result
+      result = temp
+    return
   else: discard
-  
+
   for i in 0 .. <result.len:
-    result[i] = processBody(result[i], retFutureSym, subtypeName)
-  #echo(treeRepr(result))
+    result[i] = processBody(result[i], retFutureSym, subtypeIsVoid, exceptBranch)
 
 proc getName(node: PNimrodNode): string {.compileTime.} =
   case node.kind
@@ -866,35 +921,36 @@ macro async*(prc: stmt): stmt {.immediate.} =
   hint("Processing " & prc[0].getName & " as an async proc.")
 
   let returnType = prc[3][0]
-  var subtypeName = ""
   # Verify that the return type is a PFuture[T]
   if returnType.kind == nnkIdent:
     error("Expected return type of 'PFuture' got '" & $returnType & "'")
   elif returnType.kind == nnkBracketExpr:
     if $returnType[0] != "PFuture":
       error("Expected return type of 'PFuture' got '" & $returnType[0] & "'")
-    subtypeName = $returnType[1].ident
-  elif returnType.kind == nnkEmpty:
-    subtypeName = "void"
+
+  let subtypeIsVoid = returnType.kind == nnkEmpty
 
   var outerProcBody = newNimNode(nnkStmtList)
 
   # -> var retFuture = newFuture[T]()
   var retFutureSym = genSym(nskVar, "retFuture")
+  var subRetType =
+    if returnType.kind == nnkEmpty: newIdentNode("void")
+    else: returnType[1]
   outerProcBody.add(
     newVarStmt(retFutureSym, 
       newCall(
         newNimNode(nnkBracketExpr).add(
           newIdentNode(!"newFuture"), # TODO: Strange bug here? Remove the `!`.
-          newIdentNode(subtypeName))))) # Get type from return type of this proc
+          subRetType)))) # Get type from return type of this proc
   
   # -> iterator nameIter(): PFutureBase {.closure.} = 
   # ->   var result: T
   # ->   <proc_body>
   # ->   complete(retFuture, result)
   var iteratorNameSym = genSym(nskIterator, $prc[0].getName & "Iter")
-  var procBody = prc[6].processBody(retFutureSym, subtypeName)
-  if subtypeName != "void":
+  var procBody = prc[6].processBody(retFutureSym, subtypeIsVoid, nil)
+  if not subtypeIsVoid:
     procBody.insert(0, newNimNode(nnkVarSection).add(
       newIdentDefs(newIdentNode("result"), returnType[1]))) # -> var result: T
     procBody.add(
@@ -923,7 +979,7 @@ macro async*(prc: stmt): stmt {.immediate.} =
   for i in 0 .. <result[4].len:
     if result[4][i].ident == !"async":
       result[4].del(i)
-  if subtypeName == "void":
+  if subtypeIsVoid:
     # Add discardable pragma.
     result[4].add(newIdentNode("discardable"))
     if returnType.kind == nnkEmpty:
diff --git a/lib/pure/asynchttpserver.nim b/lib/pure/asynchttpserver.nim
index 2ebd7036d..6c2414d99 100644
--- a/lib/pure/asynchttpserver.nim
+++ b/lib/pure/asynchttpserver.nim
@@ -174,7 +174,9 @@ when isMainModule:
   proc cb(req: TRequest) {.async.} =
     #echo(req.reqMethod, " ", req.url)
     #echo(req.headers)
-    await req.respond(Http200, "Hello World")
+    let headers = {"Date": "Tue, 29 Apr 2014 23:40:08 GMT",
+        "Content-type": "text/plain; charset=utf-8"}
+    await req.respond(Http200, "Hello World", headers.newStringTable())
 
   server.serve(TPort(5555), cb)
   runForever()
diff --git a/lib/pure/asyncnet.nim b/lib/pure/asyncnet.nim
index b1abf627b..9394078c8 100644
--- a/lib/pure/asyncnet.nim
+++ b/lib/pure/asyncnet.nim
@@ -97,29 +97,35 @@ proc recv*(socket: PAsyncSocket, size: int,
   ## to be read then the future will complete with a value of ``""``.
   if socket.isBuffered:
     result = newString(size)
-
-    template returnNow(readBytes: int) =
-      result.setLen(readBytes)
-      # Only increase buffer position when not peeking.
-      if (flags and MSG_PEEK) != MSG_PEEK:
-        socket.currPos.inc(readBytes)
-      return
+    let originalBufPos = socket.currPos
 
     if socket.bufLen == 0:
       let res = await socket.readIntoBuf(flags and (not MSG_PEEK))
-      if res == 0: returnNow(0)
+      if res == 0:
+        result.setLen(0)
+        return
 
     var read = 0
     while read < size:
       if socket.currPos >= socket.bufLen:
+        if (flags and MSG_PEEK) == MSG_PEEK:
+          # We don't want to get another buffer if we're peeking.
+          result.setLen(read)
+          return
         let res = await socket.readIntoBuf(flags and (not MSG_PEEK))
-        if res == 0: returnNow(read)
+        if res == 0:
+          result.setLen(read)
+          return
 
       let chunk = min(socket.bufLen-socket.currPos, size-read)
-      copyMem(addr(result[read]), addr(socket.buffer[socket.currPos+read]), chunk)
+      copyMem(addr(result[read]), addr(socket.buffer[socket.currPos]), chunk)
       read.inc(chunk)
+      socket.currPos.inc(chunk)
 
-    returnNow(read)
+    if (flags and MSG_PEEK) == MSG_PEEK:
+      # Restore old buffer cursor position.
+      socket.currPos = originalBufPos
+    result.setLen(read)
   else:
     result = await recv(socket.fd.TAsyncFD, size, flags)
 
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index 33e558aee..848f4b8ba 100644
--- a/lib/pure/collections/tables.nim
+++ b/lib/pure/collections/tables.nim
@@ -66,6 +66,7 @@ type
   TTable* {.final, myShallow.}[A, B] = object ## generic hash table
     data: TKeyValuePairSeq[A, B]
     counter: int
+  PTable*[A,B] = ref TTable[A, B]
 
 when not defined(nimhygiene):
   {.pragma: dirty.}
@@ -231,7 +232,7 @@ proc `$`*[A, B](t: TTable[A, B]): string =
   ## The `$` operator for hash tables.
   dollarImpl()
   
-proc `==`*[A, B](s, t: TTable[A, B]): bool =
+template equalsImpl() =
   if s.counter == t.counter:
     # different insertion orders mean different 'data' seqs, so we have
     # to use the slow route here:
@@ -240,6 +241,9 @@ proc `==`*[A, B](s, t: TTable[A, B]): bool =
       if t[key] != val: return false
     return true
   
+proc `==`*[A, B](s, t: TTable[A, B]): bool =
+  equalsImpl()
+  
 proc indexBy*[A, B, C](collection: A, index: proc(x: B): C): TTable[C, B] =
   ## Index the collection with the proc provided.
   # TODO: As soon as supported, change collection: A to collection: A[B]
@@ -247,6 +251,88 @@ proc indexBy*[A, B, C](collection: A, index: proc(x: B): C): TTable[C, B] =
   for item in collection:
     result[index(item)] = item
 
+proc len*[A, B](t: PTable[A, B]): int =
+  ## returns the number of keys in `t`.
+  result = t.counter
+
+iterator pairs*[A, B](t: PTable[A, B]): tuple[key: A, val: B] =
+  ## iterates over any (key, value) pair in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield (t.data[h].key, t.data[h].val)
+
+iterator mpairs*[A, B](t: PTable[A, B]): tuple[key: A, val: var B] =
+  ## iterates over any (key, value) pair in the table `t`. The values
+  ## can be modified.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield (t.data[h].key, t.data[h].val)
+
+iterator keys*[A, B](t: PTable[A, B]): A =
+  ## iterates over any key in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].key
+
+iterator values*[A, B](t: PTable[A, B]): B =
+  ## iterates over any value in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].val
+
+iterator mvalues*[A, B](t: PTable[A, B]): var B =
+  ## iterates over any value in the table `t`. The values can be modified.
+  for h in 0..high(t.data):
+    if t.data[h].slot == seFilled: yield t.data[h].val
+
+proc `[]`*[A, B](t: PTable[A, B], key: A): B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## default empty value for the type `B` is returned
+  ## and no exception is raised. One can check with ``hasKey`` whether the key
+  ## exists.
+  result = t[][key]
+
+proc mget*[A, B](t: PTable[A, B], key: A): var B =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
+  t[].mget(key)
+
+proc hasKey*[A, B](t: PTable[A, B], key: A): bool =
+  ## returns true iff `key` is in the table `t`.
+  result = t[].hasKey(key)
+
+proc `[]=`*[A, B](t: PTable[A, B], key: A, val: B) =
+  ## puts a (key, value)-pair into `t`.
+  t[][key] = val
+
+proc add*[A, B](t: PTable[A, B], key: A, val: B) =
+  ## puts a new (key, value)-pair into `t` even if ``t[key]`` already exists.
+  t[].add(key, val)
+  
+proc del*[A, B](t: PTable[A, B], key: A) =
+  ## deletes `key` from hash table `t`.
+  t[].del(key)
+
+proc newTable*[A, B](initialSize=64): PTable[A, B] =
+  new(result)
+  result[] = initTable[A, B](initialSize)
+
+proc newTable*[A, B](pairs: openArray[tuple[key: A, 
+                    val: B]]): PTable[A, B] =
+  ## creates a new hash table that contains the given `pairs`.
+  new(result)
+  result[] = toTable[A, B](pairs)
+
+proc `$`*[A, B](t: PTable[A, B]): string =
+  ## The `$` operator for hash tables.
+  dollarImpl()
+
+proc `==`*[A, B](s, t: PTable[A, B]): bool =
+  equalsImpl()
+
+proc newTableFrom*[A, B, C](collection: A, index: proc(x: B): C): PTable[C, B] =
+  ## Index the collection with the proc provided.
+  # TODO: As soon as supported, change collection: A to collection: A[B]
+  result = newTable[C, B]()
+  for item in collection:
+    result[index(item)] = item
+
 # ------------------------------ ordered table ------------------------------
 
 type
@@ -257,6 +343,7 @@ type
       final, myShallow.}[A, B] = object ## table that remembers insertion order
     data: TOrderedKeyValuePairSeq[A, B]
     counter, first, last: int
+  POrderedTable*[A, B] = ref TOrderedTable[A, B]
 
 proc len*[A, B](t: TOrderedTable[A, B]): int {.inline.} =
   ## returns the number of keys in `t`.
@@ -417,6 +504,96 @@ proc sort*[A, B](t: var TOrderedTable[A, B],
   t.first = list
   t.last = tail
 
+proc len*[A, B](t: POrderedTable[A, B]): int {.inline.} =
+  ## returns the number of keys in `t`.
+  result = t.counter
+
+template forAllOrderedPairs(yieldStmt: stmt) {.dirty, immediate.} =
+  var h = t.first
+  while h >= 0:
+    var nxt = t.data[h].next
+    if t.data[h].slot == seFilled: yieldStmt
+    h = nxt
+
+iterator pairs*[A, B](t: POrderedTable[A, B]): tuple[key: A, val: B] =
+  ## iterates over any (key, value) pair in the table `t` in insertion
+  ## order.
+  forAllOrderedPairs:
+    yield (t.data[h].key, t.data[h].val)
+
+iterator mpairs*[A, B](t: POrderedTable[A, B]): tuple[key: A, val: var B] =
+  ## iterates over any (key, value) pair in the table `t` in insertion
+  ## order. The values can be modified.
+  forAllOrderedPairs:
+    yield (t.data[h].key, t.data[h].val)
+
+iterator keys*[A, B](t: POrderedTable[A, B]): A =
+  ## iterates over any key in the table `t` in insertion order.
+  forAllOrderedPairs:
+    yield t.data[h].key
+
+iterator values*[A, B](t: POrderedTable[A, B]): B =
+  ## iterates over any value in the table `t` in insertion order.
+  forAllOrderedPairs:
+    yield t.data[h].val
+
+iterator mvalues*[A, B](t: POrderedTable[A, B]): var B =
+  ## iterates over any value in the table `t` in insertion order. The values
+  ## can be modified.
+  forAllOrderedPairs:
+    yield t.data[h].val
+
+proc `[]`*[A, B](t: POrderedTable[A, B], key: A): B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## default empty value for the type `B` is returned
+  ## and no exception is raised. One can check with ``hasKey`` whether the key
+  ## exists.
+  result = t[][key]
+
+proc mget*[A, B](t: POrderedTable[A, B], key: A): var B =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
+  result = t[].mget(key)
+
+proc hasKey*[A, B](t: POrderedTable[A, B], key: A): bool =
+  ## returns true iff `key` is in the table `t`.
+  result = t[].hasKey(key)
+
+proc `[]=`*[A, B](t: POrderedTable[A, B], key: A, val: B) =
+  ## puts a (key, value)-pair into `t`.
+  t[][key] = val
+
+proc add*[A, B](t: POrderedTable[A, B], key: A, val: B) =
+  ## puts a new (key, value)-pair into `t` even if ``t[key]`` already exists.
+  t[].add(key, val)
+
+proc newOrderedTable*[A, B](initialSize=64): POrderedTable[A, B] =
+  ## creates a new ordered hash table that is empty.
+  ##
+  ## `initialSize` needs to be a power of two. If you need to accept runtime
+  ## values for this you could use the ``nextPowerOfTwo`` proc from the
+  ## `math <math.html>`_ module.
+  new(result)
+  result[] = initOrderedTable[A, B]()
+
+proc newOrderedTable*[A, B](pairs: openArray[tuple[key: A, 
+                           val: B]]): POrderedTable[A, B] =
+  ## creates a new ordered hash table that contains the given `pairs`.
+  result = newOrderedTable[A, B](nextPowerOfTwo(pairs.len+10))
+  for key, val in items(pairs): result[key] = val
+
+proc `$`*[A, B](t: POrderedTable[A, B]): string =
+  ## The `$` operator for ordered hash tables.
+  dollarImpl()
+
+proc sort*[A, B](t: POrderedTable[A, B], 
+                 cmp: proc (x,y: tuple[key: A, val: B]): int) =
+  ## sorts `t` according to `cmp`. This modifies the internal list
+  ## that kept the insertion order, so insertion order is lost after this
+  ## call but key lookup and insertions remain possible after `sort` (in
+  ## contrast to the `sort` for count tables).
+  t[].sort(cmp)
+
 # ------------------------------ count tables -------------------------------
 
 type
@@ -424,6 +601,7 @@ type
       A] = object ## table that counts the number of each key
     data: seq[tuple[key: A, val: int]]
     counter: int
+  PCountTable*[A] = ref TCountTable[A]
 
 proc len*[A](t: TCountTable[A]): int =
   ## returns the number of keys in `t`.
@@ -567,6 +745,93 @@ proc sort*[A](t: var TCountTable[A]) =
         if j < h: break
     if h == 1: break
 
+proc len*[A](t: PCountTable[A]): int =
+  ## returns the number of keys in `t`.
+  result = t.counter
+
+iterator pairs*[A](t: PCountTable[A]): tuple[key: A, val: int] =
+  ## iterates over any (key, value) pair in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield (t.data[h].key, t.data[h].val)
+
+iterator mpairs*[A](t: PCountTable[A]): tuple[key: A, val: var int] =
+  ## iterates over any (key, value) pair in the table `t`. The values can
+  ## be modified.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield (t.data[h].key, t.data[h].val)
+
+iterator keys*[A](t: PCountTable[A]): A =
+  ## iterates over any key in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield t.data[h].key
+
+iterator values*[A](t: PCountTable[A]): int =
+  ## iterates over any value in the table `t`.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield t.data[h].val
+
+iterator mvalues*[A](t: PCountTable[A]): var int =
+  ## iterates over any value in the table `t`. The values can be modified.
+  for h in 0..high(t.data):
+    if t.data[h].val != 0: yield t.data[h].val
+
+proc `[]`*[A](t: PCountTable[A], key: A): int =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## 0 is returned. One can check with ``hasKey`` whether the key
+  ## exists.
+  result = t[][key]
+
+proc mget*[A](t: PCountTable[A], key: A): var int =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
+  result = t[].mget(key)
+
+proc hasKey*[A](t: PCountTable[A], key: A): bool =
+  ## returns true iff `key` is in the table `t`.
+  result = t[].hasKey(key)
+
+proc `[]=`*[A](t: PCountTable[A], key: A, val: int) =
+  ## puts a (key, value)-pair into `t`. `val` has to be positive.
+  assert val > 0
+  t[][key] = val
+
+proc newCountTable*[A](initialSize=64): PCountTable[A] =
+  ## creates a new count table that is empty.
+  ##
+  ## `initialSize` needs to be a power of two. If you need to accept runtime
+  ## values for this you could use the ``nextPowerOfTwo`` proc from the
+  ## `math <math.html>`_ module.
+  new(result)
+  result[] = initCountTable[A](initialSize)
+
+proc newCountTable*[A](keys: openArray[A]): PCountTable[A] =
+  ## creates a new count table with every key in `keys` having a count of 1.
+  result = newCountTable[A](nextPowerOfTwo(keys.len+10))
+  for key in items(keys): result[key] = 1
+
+proc `$`*[A](t: PCountTable[A]): string =
+  ## The `$` operator for count tables.
+  dollarImpl()
+
+proc inc*[A](t: PCountTable[A], key: A, val = 1) = 
+  ## increments `t[key]` by `val`.
+  t[].inc(key, val)
+
+proc smallest*[A](t: PCountTable[A]): tuple[key: A, val: int] =
+  ## returns the largest (key,val)-pair. Efficiency: O(n)
+  t[].smallest
+
+proc largest*[A](t: PCountTable[A]): tuple[key: A, val: int] =
+  ## returns the (key,val)-pair with the largest `val`. Efficiency: O(n)
+  t[].largest
+
+proc sort*[A](t: PCountTable[A]) =
+  ## sorts the count table so that the entry with the highest counter comes
+  ## first. This is destructive! You must not modify `t` afterwards!
+  ## You can use the iterators `pairs`,  `keys`, and `values` to iterate over
+  ## `t` in the sorted order.
+  t[].sort
+
 when isMainModule:
   type
     Person = object
diff --git a/lib/windows/winlean.nim b/lib/windows/winlean.nim
index a3aac17d4..dcae6ffaf 100644
--- a/lib/windows/winlean.nim
+++ b/lib/windows/winlean.nim
@@ -640,8 +640,8 @@ proc unmapViewOfFile*(lpBaseAddress: pointer): WINBOOL {.stdcall,
 
 type
   TOVERLAPPED* {.pure, inheritable.} = object
-    Internal*: DWORD
-    InternalHigh*: DWORD
+    Internal*: PULONG
+    InternalHigh*: PULONG
     Offset*: DWORD
     OffsetHigh*: DWORD
     hEvent*: THANDLE
@@ -672,7 +672,7 @@ proc CreateIoCompletionPort*(FileHandle: THANDLE, ExistingCompletionPort: THANDL
 
 proc GetQueuedCompletionStatus*(CompletionPort: THandle,
     lpNumberOfBytesTransferred: PDWORD, lpCompletionKey: PULONG,
-                                lpOverlapped: pointer,
+                                lpOverlapped: ptr POverlapped,
                                 dwMilliseconds: DWORD): WINBOOL{.stdcall,
     dynlib: "kernel32", importc: "GetQueuedCompletionStatus".}