got rid of unsound co/contravariance in procvars

lib/pure/osproc.nim

@@ -232,10 +232,11 @@ when defined(Windows) and not defined(useNimRtl):
       handle: THandle
       atTheEnd: bool
 
-  proc hsClose(s: PFileHandleStream) = nil # nothing to do here
-  proc hsAtEnd(s: PFileHandleStream): bool = return s.atTheEnd
+  proc hsClose(s: PStream) = nil # nothing to do here
+  proc hsAtEnd(s: PStream): bool = return PFileHandleStream(s).atTheEnd
 
-  proc hsReadData(s: PFileHandleStream, buffer: pointer, bufLen: int): int =
+  proc hsReadData(s: PStream, buffer: pointer, bufLen: int): int =
+    var s = PFileHandleStream(s)
     if s.atTheEnd: return 0
     var br: int32
     var a = winlean.ReadFile(s.handle, buffer, bufLen, br, nil)
@@ -246,7 +247,8 @@ when defined(Windows) and not defined(useNimRtl):
     s.atTheEnd = br < bufLen
     result = br
 
-  proc hsWriteData(s: PFileHandleStream, buffer: pointer, bufLen: int) =
+  proc hsWriteData(s: PStream, buffer: pointer, bufLen: int) =
+    var s = PFileHandleStream(s)
     var bytesWritten: int32
     var a = winlean.writeFile(s.handle, buffer, bufLen, bytesWritten, nil)
     if a == 0: OSError()
@@ -507,7 +509,7 @@ elif not defined(useNimRtl):
       quit("execve call failed: " & $strerror(errno))
     # Parent process. Copy process information.
     if poEchoCmd in options:
-      echo(command & " " & join(args, " "))
+      echo(command, " ", join(args, " "))
     result.id = pid
 
     result.inputHandle = p_stdin[writeIdx]

lib/pure/romans.nim

@@ -0,0 +1,59 @@
+#
+#
+#            Nimrod's Runtime Library
+#        (c) Copyright 2011 Philippe Lhoste
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Module for converting an integer to a Roman numeral.
+## See http://en.wikipedia.org/wiki/Roman_numerals for reference.
+
+const
+  RomanNumeralDigits* = {'I', 'i', 'V', 'v', 'X', 'x', 'L', 'l', 'C', 'c', 
+    'D', 'd', 'M', 'm'} ## set of all characters a Roman numeral may consist of
+
+proc romanToDecimal*(romanVal: string): int =
+  ## Converts a Roman numeral to its int representation.
+  result = 0
+  var prevVal = 0
+  for i in countdown(romanVal.len - 1, 0):
+    var val = 0
+    case romanVal[i]
+    of 'I', 'i': val = 1
+    of 'V', 'v': val = 5
+    of 'X', 'x': val = 10
+    of 'L', 'l': val = 50
+    of 'C', 'c': val = 100
+    of 'D', 'd': val = 500
+    of 'M', 'm': val = 1000
+    else: 
+      raise newException(EInvalidValue, "invalid roman numeral: " & $romanVal)
+    if val >= prevVal:
+      inc(result, val)
+    else:
+      dec(result, val)
+    prevVal = val
+
+proc decimalToRoman*(number: range[1..3_999]): string =
+  ## Converts a number to a Roman numeral.
+  const romanComposites = [
+    ("M", 1000), ("CM", 900),
+    ("D", 500), ("CD", 400), ("C", 100),
+    ("XC", 90), ("L", 50), ("XL", 40), ("X", 10), ("IX", 9),
+    ("V", 5), ("IV", 4), ("I", 1)]
+  result = ""
+  var decVal = number
+  for key, val in items(romanComposites):
+    while decVal >= val:
+      dec(decVal, val)
+      result.add(key)
+
+when isMainModule:
+  import math
+  randomize()
+  for i in 1 .. 100:
+    var rnd = 1 + random(3990)
+    assert rnd == rnd.decimalToRoman.romanToDecimal
+

lib/pure/streams.nim

@@ -104,28 +104,34 @@ type
     data*: string
     pos: int
     
-proc ssAtEnd(s: PStringStream): bool = 
+proc ssAtEnd(s: PStream): bool = 
+  var s = PStringStream(s)
   return s.pos >= s.data.len
     
-proc ssSetPosition(s: PStringStream, pos: int) = 
+proc ssSetPosition(s: PStream, pos: int) = 
+  var s = PStringStream(s)
   s.pos = min(pos, s.data.len-1)
 
-proc ssGetPosition(s: PStringStream): int =
+proc ssGetPosition(s: PStream): int =
+  var s = PStringStream(s)
   return s.pos
 
-proc ssReadData(s: PStringStream, buffer: pointer, bufLen: int): int =
+proc ssReadData(s: PStream, buffer: pointer, bufLen: int): int =
+  var s = PStringStream(s)
   result = min(bufLen, s.data.len - s.pos)
   if result > 0: 
     copyMem(buffer, addr(s.data[s.pos]), result)
     inc(s.pos, result)
 
-proc ssWriteData(s: PStringStream, buffer: pointer, bufLen: int) = 
+proc ssWriteData(s: PStream, buffer: pointer, bufLen: int) = 
+  var s = PStringStream(s)
   if bufLen > 0: 
     setLen(s.data, s.data.len + bufLen)
     copyMem(addr(s.data[s.pos]), buffer, bufLen)
     inc(s.pos, bufLen)
 
-proc ssClose(s: PStringStream) =
+proc ssClose(s: PStream) =
+  var s = PStringStream(s)
   s.data = nil
 
 proc newStringStream*(s: string = ""): PStringStream = 
@@ -145,16 +151,16 @@ type
   TFileStream* = object of TStream
     f: TFile
 
-proc fsClose(s: PFileStream) = close(s.f)
-proc fsAtEnd(s: PFileStream): bool = return EndOfFile(s.f)
-proc fsSetPosition(s: PFileStream, pos: int) = setFilePos(s.f, pos)
-proc fsGetPosition(s: PFileStream): int = return int(getFilePos(s.f))
+proc fsClose(s: PStream) = close(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))
 
-proc fsReadData(s: PFileStream, buffer: pointer, bufLen: int): int = 
-  result = readBuffer(s.f, buffer, bufLen)
+proc fsReadData(s: PStream, buffer: pointer, bufLen: int): int = 
+  result = readBuffer(PFileStream(s).f, buffer, bufLen)
   
-proc fsWriteData(s: PFileStream, buffer: pointer, bufLen: int) = 
-  if writeBuffer(s.f, buffer, bufLen) != bufLen: 
+proc fsWriteData(s: PStream, buffer: pointer, bufLen: int) = 
+  if writeBuffer(PFileStream(s).f, buffer, bufLen) != bufLen: 
     raise newEIO("cannot write to stream")
 
 proc newFileStream*(f: TFile): PFileStream =