Merge branch 'master' into vm2

Conflicts:
	compiler/sem.nim

17 files changed, 238 insertions, 130 deletions

diff --git a/compiler/ast.nim b/compiler/ast.nim
index 9d85e8ff2..1eb5bffc4 100644
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -713,7 +713,6 @@ type
                               # -1 means that the size is unkwown
     align*: int               # the type's alignment requirements
     loc*: TLoc
-    testeeName*: PIdent       # the test variable in user-defined type classes
 
   TPair*{.final.} = object 
     key*, val*: PObject
@@ -1089,7 +1088,6 @@ proc assignType(dest, src: PType) =
   dest.size = src.size
   dest.align = src.align
   dest.destructor = src.destructor
-  dest.testeeName = src.testeeName
   # this fixes 'type TLock = TSysLock':
   if src.sym != nil:
     if dest.sym != nil:
diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index c50fd4536..873c61ed4 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -240,6 +240,7 @@ proc genGenericAsgn(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
   if needToCopy notin flags or 
       tfShallow in skipTypes(dest.t, abstractVarRange).flags:
     if dest.s == OnStack or not usesNativeGC():
+      useStringh(p.module)
       linefmt(p, cpsStmts,
            "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($3));$n",
            addrLoc(dest), addrLoc(src), rdLoc(dest))
@@ -316,6 +317,7 @@ proc genAssignment(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
     if needsComplexAssignment(dest.t):
       genGenericAsgn(p, dest, src, flags)
     else:
+      useStringh(p.module)
       linefmt(p, cpsStmts,
            "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($1));$n",
            rdLoc(dest), rdLoc(src))
@@ -327,11 +329,13 @@ proc genAssignment(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
            "#genericAssignOpenArray((void*)$1, (void*)$2, $1Len0, $3);$n",
            addrLoc(dest), addrLoc(src), genTypeInfo(p.module, dest.t))
     else:
+      useStringh(p.module)
       linefmt(p, cpsStmts,
            "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($1[0])*$1Len0);$n",
            rdLoc(dest), rdLoc(src))
   of tySet:
     if mapType(ty) == ctArray:
+      useStringh(p.module)
       linefmt(p, cpsStmts, "memcpy((void*)$1, (NIM_CONST void*)$2, $3);$n",
               rdLoc(dest), rdLoc(src), toRope(getSize(dest.t)))
     else:
@@ -1361,6 +1365,7 @@ proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
       lineF(p, cpsStmts, lookupOpr[op],
            [rdLoc(i), toRope(size), rdLoc(d), rdLoc(a), rdLoc(b)])
     of mEqSet:
+      useStringh(p.module)
       binaryExprChar(p, e, d, "(memcmp($1, $2, " & $(size) & ")==0)")
     of mMulSet, mPlusSet, mMinusSet, mSymDiffSet:
       # we inline the simple for loop for better code generation:
@@ -1612,6 +1617,7 @@ proc genSetConstr(p: BProc, e: PNode, d: var TLoc) =
     if d.k == locNone: getTemp(p, e.typ, d)
     if getSize(e.typ) > 8:
       # big set:
+      useStringh(p.module)
       lineF(p, cpsStmts, "memset($1, 0, sizeof($1));$n", [rdLoc(d)])
       for i in countup(0, sonsLen(e) - 1):
         if e.sons[i].kind == nkRange:
diff --git a/compiler/cgen.nim b/compiler/cgen.nim
index 910e675e1..ad9ade63c 100644
--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
@@ -72,6 +72,11 @@ proc isSimpleConst(typ: PType): bool =
       {tyTuple, tyObject, tyArray, tyArrayConstr, tySet, tySequence} and not
       (t.kind == tyProc and t.callConv == ccClosure)
 
+proc useStringh(m: BModule) =
+  if not m.includesStringh:
+    m.includesStringh = true
+    discard lists.IncludeStr(m.headerFiles, "<string.h>")
+
 proc useHeader(m: BModule, sym: PSym) = 
   if lfHeader in sym.loc.Flags: 
     assert(sym.annex != nil)
@@ -358,19 +363,24 @@ proc resetLoc(p: BProc, loc: var TLoc) =
       # field, so disabling this should be safe:
       genObjectInit(p, cpsStmts, loc.t, loc, true)
     else:
+      useStringh(p.module)
       linefmt(p, cpsStmts, "memset((void*)$1, 0, sizeof($2));$n",
               addrLoc(loc), rdLoc(loc))
       # XXX: We can be extra clever here and call memset only 
       # on the bytes following the m_type field?
       genObjectInit(p, cpsStmts, loc.t, loc, true)
 
-proc constructLoc(p: BProc, loc: TLoc, section = cpsStmts) =
+proc constructLoc(p: BProc, loc: TLoc, isTemp = false) =
   if not isComplexValueType(skipTypes(loc.t, abstractRange)):
-    linefmt(p, section, "$1 = 0;$n", rdLoc(loc))
+    linefmt(p, cpsStmts, "$1 = 0;$n", rdLoc(loc))
   else:
-    linefmt(p, section, "memset((void*)$1, 0, sizeof($2));$n",
-            addrLoc(loc), rdLoc(loc))
-    genObjectInit(p, section, loc.t, loc, true)
+    if not isTemp or containsGarbageCollectedRef(loc.t):
+      # don't use memset for temporary values for performance if we can
+      # avoid it:
+      useStringh(p.module)
+      linefmt(p, cpsStmts, "memset((void*)$1, 0, sizeof($2));$n",
+              addrLoc(loc), rdLoc(loc))
+    genObjectInit(p, cpsStmts, loc.t, loc, true)
 
 proc initLocalVar(p: BProc, v: PSym, immediateAsgn: bool) =
   if sfNoInit notin v.flags:
@@ -396,7 +406,7 @@ proc getTemp(p: BProc, t: PType, result: var TLoc) =
   result.t = getUniqueType(t)
   result.s = OnStack
   result.flags = {}
-  constructLoc(p, result)
+  constructLoc(p, result, isTemp=true)
 
 proc keepAlive(p: BProc, toKeepAlive: TLoc) =
   when false:
@@ -418,6 +428,7 @@ proc keepAlive(p: BProc, toKeepAlive: TLoc) =
     if not isComplexValueType(skipTypes(toKeepAlive.t, abstractVarRange)):
       linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(result), rdLoc(toKeepAlive))
     else:
+      useStringh(p.module)
       linefmt(p, cpsStmts,
            "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($3));$n",
            addrLoc(result), addrLoc(toKeepAlive), rdLoc(result))
diff --git a/compiler/cgendata.nim b/compiler/cgendata.nim
index b5888d0f4..c156c40fe 100644
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -91,6 +91,7 @@ type
     FrameDeclared*: bool      # hack for ROD support so that we don't declare
                               # a frame var twice in an init proc
     isHeaderFile*: bool       # C source file is the header file
+    includesStringh*: bool    # C source file already includes ``<string.h>``
     cfilename*: string        # filename of the module (including path,
                               # without extension)
     typeCache*: TIdTable      # cache the generated types
diff --git a/compiler/extccomp.nim b/compiler/extccomp.nim
index d7f3386e3..13eb972f6 100644
--- a/compiler/extccomp.nim
+++ b/compiler/extccomp.nim
@@ -583,7 +583,7 @@ proc CallCCompiler*(projectfile: string) =
       else:
         rawMessage(errGenerated, " execution of an external program failed; " &
                    "rerun with --parallelBuild:1 to see the error message")
-  if optNoLinking notin gGlobalOptions and cmds.len > 0:
+  if optNoLinking notin gGlobalOptions:
     # call the linker:
     var it = PStrEntry(toLink.head)
     var objfiles = ""
diff --git a/compiler/lists.nim b/compiler/lists.nim
index 67b32f919..22b1a183a 100644
--- a/compiler/lists.nim
+++ b/compiler/lists.nim
@@ -91,13 +91,17 @@ proc Remove*(list: var TLinkedList, entry: PListEntry) =
   if entry.prev != nil: entry.prev.next = entry.next
 
 proc bringToFront*(list: var TLinkedList, entry: PListEntry) =
-  if entry == list.head: return
-  if entry == list.tail: list.tail = entry.prev
-  if entry.next != nil: entry.next.prev = entry.prev
-  if entry.prev != nil: entry.prev.next = entry.next
-  entry.prev = nil
-  entry.next = list.head
-  list.head = entry
+  when true:
+    list.remove entry
+    list.prepend entry
+  else:
+    if entry == list.head: return
+    if entry == list.tail: list.tail = entry.prev
+    if entry.next != nil: entry.next.prev = entry.prev
+    if entry.prev != nil: entry.prev.next = entry.next
+    entry.prev = nil
+    entry.next = list.head
+    list.head = entry
 
 proc ExcludeStr*(list: var TLinkedList, data: string) =
   var it = list.head
diff --git a/compiler/msgs.nim b/compiler/msgs.nim
index 5363442b4..895ba71f3 100644
--- a/compiler/msgs.nim
+++ b/compiler/msgs.nim
@@ -436,7 +436,14 @@ type
                                # only 8 bytes.
     line*, col*: int16
     fileIndex*: int32
-    
+  
+  TErrorOutput* = enum
+    eStdOut
+    eStdErr
+    eInMemory
+
+  TErrorOutputs* = set[TErrorOutput]
+
   ERecoverableError* = object of EInvalidValue
   ESuggestDone* = object of EBase
 
@@ -534,13 +541,27 @@ var
   gHintCounter*: int = 0
   gWarnCounter*: int = 0
   gErrorMax*: int = 1         # stop after gErrorMax errors
-  gSilence*: int              # == 0 if we produce any output at all 
 
 when useCaas:
   var stdoutSocket*: TSocket
 
+proc UnknownLineInfo*(): TLineInfo =
+  result.line = int16(-1)
+  result.col = int16(-1)
+  result.fileIndex = -1
+
+var 
+  msgContext: seq[TLineInfo] = @[]
+  lastError = UnknownLineInfo()
+  bufferedMsgs*: seq[string]
+
+  errorOutputs* = {eStdOut, eStdErr}
+
+proc clearBufferedMsgs* =
+  bufferedMsgs = nil
+
 proc SuggestWriteln*(s: string) =
-  if gSilence == 0:
+  if eStdOut in errorOutputs:
     when useCaas:
       if isNil(stdoutSocket): Writeln(stdout, s)
       else:
@@ -548,6 +569,9 @@ proc SuggestWriteln*(s: string) =
         stdoutSocket.send(s & "\c\L")
     else:
       Writeln(stdout, s)
+  
+  if eInMemory in errorOutputs:
+    bufferedMsgs.safeAdd(s)
 
 proc SuggestQuit*() =
   if not isServing:
@@ -570,14 +594,6 @@ const
   RawWarningFormat* = "Warning: $1"
   RawHintFormat* = "Hint: $1"
 
-proc UnknownLineInfo*(): TLineInfo = 
-  result.line = int16(-1)
-  result.col = int16(-1)
-  result.fileIndex = -1
-
-var 
-  msgContext: seq[TLineInfo] = @[]
-
 proc getInfoContextLen*(): int = return msgContext.len
 proc setInfoContextLen*(L: int) = setLen(msgContext, L)
 
@@ -642,14 +658,18 @@ proc addCheckpoint*(filename: string, line: int) =
 
 proc OutWriteln*(s: string) = 
   ## Writes to stdout. Always.
-  if gSilence == 0: Writeln(stdout, s)
+  if eStdOut in errorOutputs: Writeln(stdout, s)
  
 proc MsgWriteln*(s: string) = 
   ## Writes to stdout. If --stdout option is given, writes to stderr instead.
-  if gSilence == 0:
-    if gCmd == cmdIdeTools and optCDebug notin gGlobalOptions: return
-    if optStdout in gGlobalOptions: Writeln(stderr, s)
-    else: Writeln(stdout, s)
+  if gCmd == cmdIdeTools and optCDebug notin gGlobalOptions: return
+
+  if optStdout in gGlobalOptions:
+    if eStdErr in errorOutputs: Writeln(stderr, s)
+  else:
+    if eStdOut in errorOutputs: Writeln(stdout, s)
+  
+  if eInMemory in errorOutputs: bufferedMsgs.safeAdd(s)
 
 proc coordToStr(coord: int): string = 
   if coord == -1: result = "???"
@@ -736,9 +756,6 @@ proc rawMessage*(msg: TMsgKind, args: openarray[string]) =
 proc rawMessage*(msg: TMsgKind, arg: string) = 
   rawMessage(msg, [arg])
 
-var
-  lastError = UnknownLineInfo()
-
 proc writeSurroundingSrc(info: TLineInfo) =
   const indent = "  "
   MsgWriteln(indent & info.sourceLine.ropeToStr)
diff --git a/compiler/nimconf.nim b/compiler/nimconf.nim
index 507812d9c..7ec566a01 100644
--- a/compiler/nimconf.nim
+++ b/compiler/nimconf.nim
@@ -243,11 +243,6 @@ proc LoadConfigs*(cfg: string) =
     readConfigFile(pd / cfg)
     
     if gProjectName.len != 0:
-      var conffile = changeFileExt(gProjectFull, "cfg")
-      if conffile != pd / cfg and existsFile(conffile):
-        readConfigFile(conffile)
-        rawMessage(warnConfigDeprecated, conffile)
-      
       # new project wide config file:
       readConfigFile(changeFileExt(gProjectFull, "nimrod.cfg"))
  
diff --git a/compiler/nimrod.cfg b/compiler/nimrod.nimrod.cfg
index 0affe86d9..0affe86d9 100644
--- a/compiler/nimrod.cfg
+++ b/compiler/nimrod.nimrod.cfg
diff --git a/compiler/parser.nim b/compiler/parser.nim
index e8439466a..fd51b04ec 100644
--- a/compiler/parser.nim
+++ b/compiler/parser.nim
@@ -1624,10 +1624,23 @@ proc parseObject(p: var TParser): PNode =
     return
   addSon(result, parseObjectPart(p))
 
+proc parseTypeClassParam(p: var TParser): PNode =
+  if p.tok.tokType == tkVar:
+    getTok(p)
+    result = newNode(nkVarTy)
+    result.addSon(p.parseSymbol)
+  else:
+    result = p.parseSymbol
+
 proc parseTypeClass(p: var TParser): PNode =
   result = newNodeP(nkTypeClassTy, p)
   getTok(p)
-  addSon(result, p.parseSymbol)
+  var args = newNode(nkArgList)
+  addSon(result, args)
+  addSon(args, p.parseTypeClassParam)
+  while p.tok.TokType == tkComma:
+    getTok(p)
+    addSon(args, p.parseTypeClassParam)
   if p.tok.tokType == tkCurlyDotLe and p.validInd:
     addSon(result, parsePragma(p))
   else:
diff --git a/compiler/sem.nim b/compiler/sem.nim
index ee3df9f6a..f639b831a 100644
--- a/compiler/sem.nim
+++ b/compiler/sem.nim
@@ -36,7 +36,8 @@ proc semParamList(c: PContext, n, genericParams: PNode, s: PSym)
 proc addParams(c: PContext, n: PNode, kind: TSymKind)
 proc maybeAddResult(c: PContext, s: PSym, n: PNode)
 proc instGenericContainer(c: PContext, n: PNode, header: PType): PType
-proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode
+proc tryExpr(c: PContext, n: PNode,
+             flags: TExprFlags = {}, bufferErrors = false): PNode
 proc fixImmediateParams(n: PNode): PNode
 proc activate(c: PContext, n: PNode)
 proc semQuoteAst(c: PContext, n: PNode): PNode
@@ -89,6 +90,24 @@ proc commonType*(x, y: PType): PType =
     let idx = ord(b.kind in {tyArray, tyArrayConstr})
     if a.sons[idx].kind == tyEmpty: return y
     #elif b.sons[idx].kind == tyEmpty: return x
+  elif a.kind == tyRange and b.kind == tyRange:
+    # consider:  (range[0..3], range[0..4]) here. We should make that
+    # range[0..4]. But then why is (range[0..4], 6) not range[0..6]?
+    # But then why is (2,4) not range[2..4]? But I think this would break
+    # too much code. So ... it's the same range or the base type. This means
+    #  type(if b: 0 else 1) == int and not range[0..1]. For now. In the long
+    # run people expect ranges to work properly within a tuple.
+    if not sameType(a, b):
+      result = skipTypes(a, {tyRange}).skipIntLit
+    when false:
+      if a.kind != tyRange and b.kind == tyRange:
+        # XXX This really needs a better solution, but a proper fix now breaks
+        # code.
+        result = a #.skipIntLit
+      elif a.kind == tyRange and b.kind != tyRange:
+        result = b #.skipIntLit
+      elif a.kind in IntegralTypes and a.n != nil:
+        result = a #.skipIntLit
   else:
     var k = tyNone
     if a.kind in {tyRef, tyPtr}:
@@ -102,7 +121,7 @@ proc commonType*(x, y: PType): PType =
       if result.isNil: return x
       if k != tyNone:
         let r = result
-        result = NewType(k, r.owner)
+        result = newType(k, r.owner)
         result.addSonSkipIntLit(r)
 
 proc isTopLevel(c: PContext): bool {.inline.} = 
@@ -139,27 +158,28 @@ proc IsOpImpl(c: PContext, n: PNode): PNode
 proc semMacroExpr(c: PContext, n, nOrig: PNode, sym: PSym,
                   semCheck: bool = true): PNode
 
-proc symFromType(t: PType, info: TLineInfo): PSym =
-  if t.sym != nil: return t.sym
-  result = newSym(skType, getIdent"AnonType", t.owner, info)
-  result.flags.incl sfAnon
-  result.typ = t
+when false:
+  proc symFromType(t: PType, info: TLineInfo): PSym =
+    if t.sym != nil: return t.sym
+    result = newSym(skType, getIdent"AnonType", t.owner, info)
+    result.flags.incl sfAnon
+    result.typ = t
 
-proc symNodeFromType(c: PContext, t: PType, info: TLineInfo): PNode =
-  result = newSymNode(symFromType(t, info), info)
-  result.typ = makeTypeDesc(c, t)
+  proc symNodeFromType(c: PContext, t: PType, info: TLineInfo): PNode =
+    result = newSymNode(symFromType(t, info), info)
+    result.typ = makeTypeDesc(c, t)
 
 when false:
   proc createEvalContext(c: PContext, mode: TEvalMode): PEvalContext =
     result = newEvalContext(c.module, mode)
     result.getType = proc (n: PNode): PNode =
-      var e = tryExpr(c, n)
-      if e == nil:
-        result = symNodeFromType(c, errorType(c), n.info)
-      elif e.typ == nil:
+      result = tryExpr(c, n)
+      if result == nil:
+        result = newSymNode(errorSym(c, n))
+      elif result.typ == nil:
         result = newSymNode(getSysSym"void")
       else:
-        result = symNodeFromType(c, e.typ, n.info)
+        result.typ = makeTypeDesc(c, result.typ)
 
     result.handleIsOperator = proc (n: PNode): PNode =
       result = IsOpImpl(c, n)
@@ -215,7 +235,8 @@ proc semAfterMacroCall(c: PContext, n: PNode, s: PSym): PNode =
     of tyTypeDesc:
       if n.kind == nkStmtList: result.kind = nkStmtListType
       var typ = semTypeNode(c, result, nil)
-      result = symNodeFromType(c, typ, n.info)
+      result.typ = makeTypeDesc(c, typ)
+      #result = symNodeFromType(c, typ, n.info)
     else:
       result = semExpr(c, result)
       result = fitNode(c, s.typ.sons[0], result)
diff --git a/compiler/semdata.nim b/compiler/semdata.nim
index 9ab365c9d..650a399f7 100644
--- a/compiler/semdata.nim
+++ b/compiler/semdata.nim
@@ -60,6 +60,7 @@ type
     threadEntries*: TSymSeq    # list of thread entries to check
     AmbiguousSymbols*: TIntSet # ids of all ambiguous symbols (cannot
                                # store this info in the syms themselves!)
+    InTypeClass*: int          # > 0 if we are in a user-defined type class
     InGenericContext*: int     # > 0 if we are in a generic type
     InUnrolledContext*: int    # > 0 if we are unrolling a loop
     InCompilesContext*: int    # > 0 if we are in a ``compiles`` magic
@@ -72,7 +73,8 @@ type
     libs*: TLinkedList         # all libs used by this module
     semConstExpr*: proc (c: PContext, n: PNode): PNode {.nimcall.} # for the pragmas
     semExpr*: proc (c: PContext, n: PNode, flags: TExprFlags = {}): PNode {.nimcall.}
-    semTryExpr*: proc (c: PContext, n: PNode, flags: TExprFlags = {}): PNode {.nimcall.}
+    semTryExpr*: proc (c: PContext, n: PNode,flags: TExprFlags = {},
+                       bufferErrors = false): PNode {.nimcall.}
     semOperand*: proc (c: PContext, n: PNode, flags: TExprFlags = {}): PNode {.nimcall.}
     semConstBoolExpr*: proc (c: PContext, n: PNode): PNode {.nimcall.} # XXX bite the bullet
     semOverloadedCall*: proc (c: PContext, n, nOrig: PNode,
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index b5d3ced66..78d828e43 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -191,7 +191,7 @@ proc isCastable(dst, src: PType): bool =
 proc isSymChoice(n: PNode): bool {.inline.} =
   result = n.kind in nkSymChoices
 
-proc semConv(c: PContext, n: PNode, s: PSym): PNode =
+proc semConv(c: PContext, n: PNode): PNode =
   if sonsLen(n) != 2:
     LocalError(n.info, errConvNeedsOneArg)
     return n
@@ -299,7 +299,7 @@ proc semOf(c: PContext, n: PNode): PNode =
   n.typ = getSysType(tyBool)
   result = n
 
-proc IsOpImpl(c: PContext, n: PNode): PNode =
+proc isOpImpl(c: PContext, n: PNode): PNode =
   InternalAssert n.sonsLen == 3 and
     n[1].kind == nkSym and n[1].sym.kind == skType and
     n[2].kind in {nkStrLit..nkTripleStrLit, nkType}
@@ -321,10 +321,19 @@ proc IsOpImpl(c: PContext, n: PNode): PNode =
   else:
     var match: bool
     let t2 = n[2].typ
-    if t2.kind == tyTypeClass:
+    case t2.kind
+    of tyTypeClass:
       var m: TCandidate
       InitCandidate(m, t2)
       match = matchUserTypeClass(c, m, emptyNode, t2, t1) != nil
+    of tyOrdinal:
+      var m: TCandidate
+      InitCandidate(m, t2)
+      match = isOrdinalType(t1)
+    of tySequence, tyArray, tySet:
+      var m: TCandidate
+      InitCandidate(m, t2)
+      match = typeRel(m, t2, t1) != isNone
     else:
       match = sameType(t1, t2)
  
@@ -353,7 +362,7 @@ proc semIs(c: PContext, n: PNode): PNode =
 
   let t1 = n[1].typ.sons[0]
   # BUGFIX: don't evaluate this too early: ``T is void``
-  if not containsGenericType(t1): result = IsOpImpl(c, n)
+  if not containsGenericType(t1): result = isOpImpl(c, n)
 
 proc semOpAux(c: PContext, n: PNode) =
   const flags = {efDetermineType}
@@ -729,8 +738,7 @@ proc semIndirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
   elif t != nil and t.kind == tyTypeDesc:
     if n.len == 1: return semObjConstr(c, n, flags)
     let destType = t.skipTypes({tyTypeDesc, tyGenericInst})
-    result = semConv(c, n, symFromType(destType, n.info))
-    return
+    return semConv(c, n)
   else:
     result = overloadedCallOpr(c, n)
     # Now that nkSym does not imply an iteration over the proc/iterator space,
@@ -763,7 +771,8 @@ proc afterCallActions(c: PContext; n, orig: PNode, flags: TExprFlags): PNode =
     analyseIfAddressTakenInCall(c, result)
     if callee.magic != mNone:
       result = magicsAfterOverloadResolution(c, result, flags)
-  result = evalAtCompileTime(c, result)
+  if c.InTypeClass == 0:
+    result = evalAtCompileTime(c, result)
 
 proc semDirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode = 
   # this seems to be a hotspot in the compiler!
@@ -814,7 +823,7 @@ proc buildEchoStmt(c: PContext, n: PNode): PNode =
 
 proc semExprNoType(c: PContext, n: PNode): PNode =
   result = semExpr(c, n, {efWantStmt})
-  discardCheck(result)
+  discardCheck(c, result)
   
 proc isTypeExpr(n: PNode): bool = 
   case n.kind
@@ -1038,7 +1047,9 @@ proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode =
     # The result so far is a tyTypeDesc bound 
     # a tyGenericBody. The line below will substitute
     # it with the instantiated type.
-    result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
+    result = n
+    result.typ = makeTypeDesc(c, semTypeNode(c, n, nil))
+    #result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
   of tyTuple: 
     checkSonsLen(n, 2)
     n.sons[0] = makeDeref(n.sons[0])
@@ -1208,7 +1219,7 @@ proc semProcBody(c: PContext, n: PNode): PNode =
       a.sons[1] = result
       result = semAsgn(c, a)
   else:
-    discardCheck(result)
+    discardCheck(c, result)
   closeScope(c)
 
 proc SemYieldVarResult(c: PContext, n: PNode, restype: PType) =
@@ -1429,12 +1440,12 @@ proc semQuoteAst(c: PContext, n: PNode): PNode =
     newNode(nkCall, n.info, quotes)])
   result = semExpandToAst(c, result)
 
-proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
+proc tryExpr(c: PContext, n: PNode,
+             flags: TExprFlags = {}, bufferErrors = false): PNode =
   # watch out, hacks ahead:
   let oldErrorCount = msgs.gErrorCounter
   let oldErrorMax = msgs.gErrorMax
   inc c.InCompilesContext
-  inc msgs.gSilence
   # do not halt after first error:
   msgs.gErrorMax = high(int)
   
@@ -1443,6 +1454,8 @@ proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
   openScope(c)
   let oldOwnerLen = len(gOwners)
   let oldGenerics = c.generics
+  let oldErrorOutputs = errorOutputs
+  errorOutputs = if bufferErrors: {eInMemory} else: {}
   let oldContextLen = msgs.getInfoContextLen()
   
   let oldInGenericContext = c.InGenericContext
@@ -1465,7 +1478,7 @@ proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
   setlen(gOwners, oldOwnerLen)
   c.currentScope = oldScope
   dec c.InCompilesContext
-  dec msgs.gSilence
+  errorOutputs = oldErrorOutputs
   msgs.gErrorCounter = oldErrorCount
   msgs.gErrorMax = oldErrorMax
 
@@ -1871,7 +1884,8 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
     result = semExpr(c, n.sons[0], flags)
   of nkTypeOfExpr, nkTupleTy, nkRefTy..nkEnumTy:
     var typ = semTypeNode(c, n, nil).skipTypes({tyTypeDesc})
-    result = symNodeFromType(c, typ, n.info)
+    result.typ = makeTypeDesc(c, typ)
+    #result = symNodeFromType(c, typ, n.info)
   of nkCall, nkInfix, nkPrefix, nkPostfix, nkCommand, nkCallStrLit: 
     # check if it is an expression macro:
     checkMinSonsLen(n, 1)
@@ -1894,7 +1908,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
       of skType:
         # XXX think about this more (``set`` procs)
         if n.len == 2:
-          result = semConv(c, n, s)
+          result = semConv(c, n)
         elif n.len == 1:
           result = semObjConstr(c, n, flags)
         elif Contains(c.AmbiguousSymbols, s.id): 
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index 441102989..cd714ef6e 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -132,7 +132,7 @@ proc fixNilType(n: PNode) =
     for it in n: fixNilType(it)
   n.typ = nil
 
-proc discardCheck(result: PNode) =
+proc discardCheck(c: PContext, result: PNode) =
   if result.typ != nil and result.typ.kind notin {tyStmt, tyEmpty}:
     if result.kind == nkNilLit:
       result.typ = nil
@@ -142,6 +142,10 @@ proc discardCheck(result: PNode) =
       while n.kind in skipForDiscardable:
         n = n.lastSon
         n.typ = nil
+    elif c.InTypeClass > 0 and result.typ.kind == tyBool:
+      let verdict = semConstExpr(c, result)
+      if verdict.intVal == 0:
+        localError(result.info, "type class predicate failed.")
     elif result.typ.kind != tyError and gCmd != cmdInteractive:
       if result.typ.kind == tyNil:
         fixNilType(result)
@@ -169,7 +173,7 @@ proc semIf(c: PContext, n: PNode): PNode =
       typ = commonType(typ, it.sons[0].typ)
     else: illFormedAst(it)
   if isEmptyType(typ) or typ.kind == tyNil or not hasElse:
-    for it in n: discardCheck(it.lastSon)
+    for it in n: discardCheck(c, it.lastSon)
     result.kind = nkIfStmt
     # propagate any enforced VoidContext:
     if typ == EnforceVoidContext: result.typ = EnforceVoidContext
@@ -230,7 +234,7 @@ proc semCase(c: PContext, n: PNode): PNode =
       localError(n.info, errNotAllCasesCovered)
   closeScope(c)
   if isEmptyType(typ) or typ.kind == tyNil or not hasElse:
-    for i in 1..n.len-1: discardCheck(n.sons[i].lastSon)
+    for i in 1..n.len-1: discardCheck(c, n.sons[i].lastSon)
     # propagate any enforced VoidContext:
     if typ == EnforceVoidContext:
       result.typ = EnforceVoidContext
@@ -275,8 +279,8 @@ proc semTry(c: PContext, n: PNode): PNode =
     typ = commonType(typ, a.sons[length-1].typ)
   dec c.p.inTryStmt
   if isEmptyType(typ) or typ.kind == tyNil:
-    discardCheck(n.sons[0])
-    for i in 1..n.len-1: discardCheck(n.sons[i].lastSon)
+    discardCheck(c, n.sons[0])
+    for i in 1..n.len-1: discardCheck(c, n.sons[i].lastSon)
     if typ == EnforceVoidContext:
       result.typ = EnforceVoidContext
   else:
@@ -881,8 +885,9 @@ proc semLambda(c: PContext, n: PNode, flags: TExprFlags): PNode =
   openScope(c)
   if n.sons[genericParamsPos].kind != nkEmpty:
     illFormedAst(n)           # process parameters:
-  if n.sons[paramsPos].kind != nkEmpty: 
-    semParamList(c, n.sons[ParamsPos], nil, s)
+  if n.sons[paramsPos].kind != nkEmpty:
+    var gp = newNodeI(nkGenericParams, n.info)
+    semParamList(c, n.sons[ParamsPos], gp, s)
     ParamsTypeCheck(c, s.typ)
   else:
     s.typ = newTypeS(tyProc, c)
@@ -1084,6 +1089,8 @@ proc semIterator(c: PContext, n: PNode): PNode =
   # -- at least for 0.9.2.
   if s.typ.callConv == ccClosure:
     incl(s.typ.flags, tfCapturesEnv)
+  else:
+    s.typ.callConv = ccInline
   when false:
     if s.typ.callConv != ccInline: 
       s.typ.callConv = ccClosure
@@ -1106,24 +1113,24 @@ proc finishMethod(c: PContext, s: PSym) =
     methodDef(s, false)
 
 proc semMethod(c: PContext, n: PNode): PNode = 
-  if not isTopLevel(c): LocalError(n.info, errXOnlyAtModuleScope, "method")
+  if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "method")
   result = semProcAux(c, n, skMethod, methodPragmas)
   
   var s = result.sons[namePos].sym
-  if not isGenericRoutine(s):
+  if not isGenericRoutine(s) and result.sons[bodyPos].kind != nkEmpty:
     if hasObjParam(s):
-      methodDef(s, false)
+      methodDef(s, fromCache=false)
     else:
-      LocalError(n.info, errXNeedsParamObjectType, "method")
+      localError(n.info, errXNeedsParamObjectType, "method")
 
 proc semConverterDef(c: PContext, n: PNode): PNode = 
-  if not isTopLevel(c): LocalError(n.info, errXOnlyAtModuleScope, "converter")
+  if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "converter")
   checkSonsLen(n, bodyPos + 1)
   result = semProcAux(c, n, skConverter, converterPragmas)
   var s = result.sons[namePos].sym
   var t = s.typ
-  if t.sons[0] == nil: LocalError(n.info, errXNeedsReturnType, "converter")
-  if sonsLen(t) != 2: LocalError(n.info, errXRequiresOneArgument, "converter")
+  if t.sons[0] == nil: localError(n.info, errXNeedsReturnType, "converter")
+  if sonsLen(t) != 2: localError(n.info, errXRequiresOneArgument, "converter")
   addConverter(c, s)
 
 proc semMacroDef(c: PContext, n: PNode): PNode = 
@@ -1131,9 +1138,9 @@ proc semMacroDef(c: PContext, n: PNode): PNode =
   result = semProcAux(c, n, skMacro, macroPragmas)
   var s = result.sons[namePos].sym
   var t = s.typ
-  if t.sons[0] == nil: LocalError(n.info, errXNeedsReturnType, "macro")
+  if t.sons[0] == nil: localError(n.info, errXNeedsReturnType, "macro")
   if n.sons[bodyPos].kind == nkEmpty:
-    LocalError(n.info, errImplOfXexpected, s.name.s)
+    localError(n.info, errImplOfXexpected, s.name.s)
   
 proc evalInclude(c: PContext, n: PNode): PNode =
   result = newNodeI(nkStmtList, n.info)
@@ -1223,7 +1230,7 @@ proc semStmtList(c: PContext, n: PNode): PNode =
         voidContext = true
         n.typ = EnforceVoidContext
       if i != last or voidContext:
-        discardCheck(n.sons[i])
+        discardCheck(c, n.sons[i])
       else:
         n.typ = n.sons[i].typ
         if not isEmptyType(n.typ):
diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index b9893d037..92f47f585 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -876,8 +876,7 @@ proc freshType(res, prev: PType): PType {.inline.} =
 proc semTypeClass(c: PContext, n: PNode, prev: PType): PType =
   # if n.sonsLen == 0: return newConstraint(c, tyTypeClass)
   result = newOrPrevType(tyTypeClass, prev, c)
-  result.testeeName = considerAcc(n[0])
-  result.n = n[3]
+  result.n = n
 
   let
     pragmas = n[1]
diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index 318acc660..00f3b2b10 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -85,6 +85,7 @@ proc initCandidate*(c: var TCandidate, callee: PSym, binding: PNode,
   c.calleeSym = callee
   c.calleeScope = calleeScope
   initIdTable(c.bindings)
+  c.errors = nil
   if binding != nil and callee.kind in RoutineKinds:
     var typeParams = callee.ast[genericParamsPos]
     for i in 1..min(sonsLen(typeParams), sonsLen(binding)-1):
@@ -202,7 +203,7 @@ proc describeArgs*(c: PContext, n: PNode, startIdx = 1): string =
     add(result, argTypeToString(arg))
     if i != sonsLen(n) - 1: add(result, ", ")
 
-proc typeRel(c: var TCandidate, f, a: PType): TTypeRelation
+proc typeRel*(c: var TCandidate, f, a: PType): TTypeRelation
 proc concreteType(c: TCandidate, t: PType): PType = 
   case t.kind
   of tyArrayConstr: 
@@ -750,40 +751,55 @@ proc matchUserTypeClass*(c: PContext, m: var TCandidate,
 
   # pushInfoContext(arg.info)
   openScope(c)
+  inc c.InTypeClass
 
-  var testee = newSym(skParam, f.testeeName, f.sym, f.sym.info)
-  testee.typ = a
-  addDecl(c, testee)
+  finally:
+    dec c.InTypeClass
+    closeScope(c)
 
-  for stmt in f.n:
-    var e = c.semTryExpr(c, copyTree(stmt))
-    if e == nil:
-      let expStr = renderTree(stmt, {renderNoComments})
-      m.errors.safeAdd("can't compile " & expStr & "  for " & a.typeToString)
-      return nil
-    case e.kind
-    of nkReturnStmt:
-      nil
-    of nkTypeSection: nil
-    of nkConstDef: nil
+  for param in f.n[0]:
+    var
+      dummyName: PNode
+      dummyType: PType
+    
+    if param.kind == nkVarTy:
+      dummyName = param[0]
+      dummyType = makeVarType(c, a)
     else:
-      if e.typ.kind == tyBool:
-        let verdict = c.semConstExpr(c, e)
-        if verdict.intVal == 0:
-          let expStr = renderTree(stmt, {renderNoComments})
-          m.errors.safeAdd(expStr & " doesn't hold for " & a.typeToString)
-          return nil
+      dummyName = param
+      dummyType = a
+
+    InternalAssert dummyName.kind == nkIdent
+    var dummyParam = newSym(skType, dummyName.ident, f.sym, f.sym.info)
+    dummyParam.typ = dummyType
+    addDecl(c, dummyParam)
 
-  closeScope(c)
+  for stmt in f.n[3]:
+    var e = c.semTryExpr(c, copyTree(stmt), bufferErrors = false)
+    m.errors = bufferedMsgs
+    clearBufferedMsgs()
+    if e == nil: return nil
 
+    case e.kind
+    of nkReturnStmt: nil
+    of nkTypeSection: nil
+    of nkConstDef: nil
+    else: nil
+  
   result = arg
   put(m.bindings, f, a)
 
-proc ParamTypesMatchAux(c: PContext, m: var TCandidate, f, a: PType, 
+proc ParamTypesMatchAux(c: PContext, m: var TCandidate, f, argType: PType,
                         argSemantized, argOrig: PNode): PNode =
-  var arg = argSemantized
-  var r: TTypeRelation
-  let fMaybeExpr = f.skipTypes({tyDistinct})
+  var
+    r: TTypeRelation
+    arg = argSemantized
+
+  let
+    a = if c.InTypeClass > 0: argType.skipTypes({tyTypeDesc})
+        else: argType
+    fMaybeExpr = f.skipTypes({tyDistinct})
+
   case fMaybeExpr.kind
   of tyExpr:
     if fMaybeExpr.sonsLen == 0:
diff --git a/compiler/types.nim b/compiler/types.nim
index f9c40e201..4dec9ea2f 100644
--- a/compiler/types.nim
+++ b/compiler/types.nim
@@ -621,7 +621,7 @@ type
 proc initSameTypeClosure: TSameTypeClosure =
   # we do the initialization lazily for performance (avoids memory allocations)
   nil
-
+  
 proc containsOrIncl(c: var TSameTypeClosure, a, b: PType): bool =
   result = not IsNil(c.s) and c.s.contains((a.id, b.id))
   if not result:
@@ -750,9 +750,9 @@ template IfFastObjectTypeCheckFailed(a, b: PType, body: stmt) {.immediate.} =
 
 proc sameObjectTypes*(a, b: PType): bool =
   # specialized for efficiency (sigmatch uses it)
-  IfFastObjectTypeCheckFailed(a, b):
+  IfFastObjectTypeCheckFailed(a, b):     
     var c = initSameTypeClosure()
-    result = sameTypeAux(a, b, c)
+    result = sameTypeAux(a, b, c)    
 
 proc sameDistinctTypes*(a, b: PType): bool {.inline.} =
   result = sameObjectTypes(a, b)
@@ -808,11 +808,11 @@ proc SameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
       if containsOrIncl(c, a, b): return true
 
   proc sameFlags(a, b: PType): bool {.inline.} =
-    result = eqTypeFlags*a.flags == eqTypeFlags*b.flags
-    
+    result = eqTypeFlags*a.flags == eqTypeFlags*b.flags   
+
   if x == y: return true
   var a = skipTypes(x, {tyGenericInst})
-  var b = skipTypes(y, {tyGenericInst})
+  var b = skipTypes(y, {tyGenericInst})  
   assert(a != nil)
   assert(b != nil)
   if a.kind != b.kind:
@@ -824,7 +824,7 @@ proc SameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
       if a.kind != b.kind: return false
     of dcEqOrDistinctOf:
       while a.kind == tyDistinct: a = a.sons[0]
-      if a.kind != b.kind: return false
+      if a.kind != b.kind: return false  
   case a.Kind
   of tyEmpty, tyChar, tyBool, tyNil, tyPointer, tyString, tyCString,
      tyInt..tyBigNum, tyStmt:
@@ -837,15 +837,19 @@ proc SameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
       result = sameObjectStructures(a, b, c) and sameFlags(a, b)
   of tyDistinct:
     CycleCheck()
-    if c.cmp == dcEq: result = sameDistinctTypes(a, b) and sameFlags(a, b)
-    else: result = sameTypeAux(a.sons[0], b.sons[0], c) and sameFlags(a, b)
+    if c.cmp == dcEq:      
+      if sameFlags(a, b):
+        IfFastObjectTypeCheckFailed(a, b):
+          result = sameTypeAux(a.sons[0], b.sons[0], c)     
+    else: 
+      result = sameTypeAux(a.sons[0], b.sons[0], c) and sameFlags(a, b)
   of tyEnum, tyForward, tyProxy:
     # XXX generic enums do not make much sense, but require structural checking
     result = a.id == b.id and sameFlags(a, b)
   of tyTuple:
     CycleCheck()
     result = sameTuple(a, b, c) and sameFlags(a, b)
-  of tyGenericInst:
+  of tyGenericInst:    
     result = sameTypeAux(lastSon(a), lastSon(b), c)
   of tyTypeDesc:
     if c.cmp == dcEqIgnoreDistinct: result = false
@@ -858,7 +862,7 @@ proc SameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
      tyOpenArray, tySet, tyRef, tyPtr, tyVar, tyArrayConstr,
      tyArray, tyProc, tyConst, tyMutable, tyVarargs, tyIter,
      tyOrdinal, tyTypeClass:
-    CycleCheck()
+    CycleCheck()    
     result = sameChildrenAux(a, b, c) and sameFlags(a, b)
     if result and (a.kind == tyProc):
       result = a.callConv == b.callConv
@@ -867,7 +871,7 @@ proc SameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
     result = SameTypeOrNilAux(a.sons[0], b.sons[0], c) and
         SameValue(a.n.sons[0], b.n.sons[0]) and
         SameValue(a.n.sons[1], b.n.sons[1])
-  of tyNone: result = false
+  of tyNone: result = false  
 
 proc sameType*(x, y: PType): bool =
   var c = initSameTypeClosure()