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

31 files changed, 1056 insertions, 709 deletions

diff --git a/compiler/ast.nim b/compiler/ast.nim
index 5a3af27e8..1d356b6d8 100644
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -192,6 +192,7 @@ type
     nkObjectTy,           # object body
     nkTupleTy,            # tuple body
     nkTypeClassTy,        # user-defined type class
+    nkStaticTy,           # ``static[T]``
     nkRecList,            # list of object parts
     nkRecCase,            # case section of object
     nkRecWhen,            # when section of object
@@ -336,19 +337,38 @@ type
     tyIter, # unused
     tyProxy # used as errornous type (for idetools)
     tyTypeClass
-    tyAnd
-    tyOr
-    tyNot
-    tyAnything
     tyParametricTypeClass # structured similarly to tyGenericInst
                           # lastSon is the body of the type class
+    
+    tyBuiltInTypeClass # Type such as the catch-all object, tuple, seq, etc
+    
+    tyCompositeTypeClass # 
+    
+    tyAnd, tyOr, tyNot # boolean type classes such as `string|int`,`not seq`,
+                       # `Sortable and Enumable`, etc
+    
+    tyAnything # a type class matching any type
+    
+    tyStatic   # a value known at compile type (the underlying type is .base)
+    
+    tyFromExpr # This is a type representing an expression that depends
+               # on generic parameters (the exprsesion is stored in t.n)
+               # It will be converted to a real type only during generic
+               # instantiation and prior to this it has the potential to
+               # be any type.
 
 const
   tyPureObject* = tyTuple
   GcTypeKinds* = {tyRef, tySequence, tyString}
   tyError* = tyProxy # as an errornous node should match everything
-  tyTypeClasses* = {tyTypeClass, tyParametricTypeClass, tyAnd, tyOr, tyNot, tyAnything}
 
+  tyUnknownTypes* = {tyError, tyFromExpr}
+
+  tyTypeClasses* = {tyTypeClass, tyBuiltInTypeClass, tyCompositeTypeClass,
+                    tyParametricTypeClass, tyAnd, tyOr, tyNot, tyAnything}
+
+  tyMetaTypes* = {tyGenericParam, tyTypeDesc, tyStatic, tyExpr} + tyTypeClasses
+ 
 type
   TTypeKinds* = set[TTypeKind]
 
@@ -383,9 +403,6 @@ type
                       # proc foo(T: typedesc, list: seq[T]): var T
     tfRetType,        # marks return types in proc (used to detect type classes 
                       # used as return types for return type inference)
-    tfAll,            # type class requires all constraints to be met (default)
-    tfAny,            # type class requires any constraint to be met
-    tfNot,            # type class with a negative check
     tfCapturesEnv,    # whether proc really captures some environment
     tfByCopy,         # pass object/tuple by copy (C backend)
     tfByRef,          # pass object/tuple by reference (C backend)
@@ -396,8 +413,12 @@ type
     tfNeedsInit,      # type constains a "not nil" constraint somewhere or some
                       # other type so that it requires inititalization
     tfHasShared,      # type constains a "shared" constraint modifier somewhere
-    tfHasMeta,        # type has "typedesc" or "expr" somewhere; or uses '|'
+    tfHasMeta,        # type contains "wildcard" sub-types such as generic params
+                      # or other type classes
     tfHasGCedMem,     # type contains GC'ed memory
+    tfHasStatic
+    tfGenericTypeParam
+    tfImplicitTypeParam
 
   TTypeFlags* = set[TTypeFlag]
 
@@ -774,9 +795,11 @@ const
 
   GenericTypes*: TTypeKinds = {tyGenericInvokation, tyGenericBody, 
     tyGenericParam}
+  
   StructuralEquivTypes*: TTypeKinds = {tyArrayConstr, tyNil, tyTuple, tyArray, 
     tySet, tyRange, tyPtr, tyRef, tyVar, tySequence, tyProc, tyOpenArray,
     tyVarargs}
+  
   ConcreteTypes*: TTypeKinds = { # types of the expr that may occur in::
                                  # var x = expr
     tyBool, tyChar, tyEnum, tyArray, tyObject, 
@@ -895,6 +918,9 @@ template `{}=`*(n: PNode, i: int, s: PNode): stmt =
 var emptyNode* = newNode(nkEmpty)
 # There is a single empty node that is shared! Do not overwrite it!
 
+proc isMetaType*(t: PType): bool =
+  return t.kind in tyMetaTypes or tfHasMeta in t.flags
+
 proc linkTo*(t: PType, s: PSym): PType {.discardable.} =
   t.sym = s
   s.typ = t
@@ -1216,10 +1242,14 @@ proc newSons(father: PNode, length: int) =
   else:
     setLen(father.sons, length)
 
+proc skipTypes*(t: PType, kinds: TTypeKinds): PType =
+  result = t
+  while result.kind in kinds: result = lastSon(result)
+
 proc propagateToOwner*(owner, elem: PType) =
   const HaveTheirOwnEmpty = {tySequence, tySet}
   owner.flags = owner.flags + (elem.flags * {tfHasShared, tfHasMeta,
-                                             tfHasGCedMem})
+                                             tfHasStatic, tfHasGCedMem})
   if tfNotNil in elem.flags:
     if owner.kind in {tyGenericInst, tyGenericBody, tyGenericInvokation}:
       owner.flags.incl tfNotNil
@@ -1232,10 +1262,14 @@ proc propagateToOwner*(owner, elem: PType) =
     
   if tfShared in elem.flags:
     owner.flags.incl tfHasShared
-  
-  if elem.kind in {tyExpr, tyTypeDesc}:
+
+  if elem.kind in tyMetaTypes:
     owner.flags.incl tfHasMeta
-  elif elem.kind in {tyString, tyRef, tySequence} or
+
+  if elem.kind == tyStatic:
+    owner.flags.incl tfHasStatic
+
+  if elem.kind in {tyString, tyRef, tySequence} or
       elem.kind == tyProc and elem.callConv == ccClosure:
     owner.flags.incl tfHasGCedMem
 
@@ -1409,6 +1443,10 @@ proc skipGenericOwner*(s: PSym): PSym =
   result = if sfFromGeneric in s.flags: s.owner.owner
            else: s.owner
 
+proc originatingModule*(s: PSym): PSym =
+  result = s.owner
+  while result.kind != skModule: result = result.owner
+
 proc isRoutine*(s: PSym): bool {.inline.} =
   result = s.kind in {skProc, skTemplate, skMacro, skIterator, skMethod,
                       skConverter}
diff --git a/compiler/astalgo.nim b/compiler/astalgo.nim
index 4b7348566..110ee191f 100644
--- a/compiler/astalgo.nim
+++ b/compiler/astalgo.nim
@@ -432,6 +432,8 @@ proc debugTree(n: PNode, indent: int, maxRecDepth: int): PRope =
 proc debug(n: PSym) =
   if n == nil:
     writeln(stdout, "null")
+  elif n.kind == skUnknown:
+    writeln(stdout, "skUnknown")
   else:
     #writeln(stdout, ropeToStr(symToYaml(n, 0, 1)))
     writeln(stdout, ropeToStr(ropef("$1_$2: $3, $4", [
diff --git a/compiler/ccgutils.nim b/compiler/ccgutils.nim
index 1c2d7e038..fe349174f 100644
--- a/compiler/ccgutils.nim
+++ b/compiler/ccgutils.nim
@@ -86,9 +86,8 @@ proc getUniqueType*(key: PType): PType =
     if result == nil:
       gCanonicalTypes[k] = key
       result = key
-  of tyTypeDesc, tyTypeClasses:
-    internalError("value expected, but got a type")
-  of tyGenericParam:
+  of tyTypeDesc, tyTypeClasses, tyGenericParam,
+     tyFromExpr, tyStatic:
     internalError("GetUniqueType")
   of tyGenericInst, tyDistinct, tyOrdinal, tyMutable, tyConst, tyIter:
     result = getUniqueType(lastSon(key))
diff --git a/compiler/cgen.nim b/compiler/cgen.nim
index c74f0807d..b08647512 100644
--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
@@ -194,7 +194,7 @@ when compileTimeRopeFmt:
       if i - 1 >= start:
         yield (kind: ffLit, value: substr(s, start, i-1), intValue: 0)
 
-  macro rfmt(m: BModule, fmt: expr[string], args: varargs[PRope]): expr =
+  macro rfmt(m: BModule, fmt: static[string], args: varargs[PRope]): expr =
     ## Experimental optimized rope-formatting operator
     ## The run-time code it produces will be very fast, but will it speed up
     ## the compilation of nimrod itself or will the macro execution time
@@ -209,7 +209,7 @@ when compileTimeRopeFmt:
       of ffParam:
         result.add(args[frag.intValue])
 else:
-  template rfmt(m: BModule, fmt: expr[string], args: varargs[PRope]): expr =
+  template rfmt(m: BModule, fmt: string, args: varargs[PRope]): expr =
     ropecg(m, fmt, args)
 
 proc appcg(m: BModule, c: var PRope, frmt: TFormatStr, 
@@ -943,44 +943,60 @@ proc genFilenames(m: BModule): PRope =
   for i in 0.. <fileInfos.len:
     result.appf("dbgRegisterFilename($1);$n", fileInfos[i].projPath.makeCString)
 
-proc genMainProc(m: BModule) = 
+proc genMainProc(m: BModule) =
   const 
-    CommonMainBody =
-        "\tsystemDatInit();$n" &
-        "\tsystemInit();$n" &
-        "$1" &
-        "$2" &
-        "$3" &
-        "$4"
-    PosixNimMain = 
-        "int cmdCount;$n" & 
-        "char** cmdLine;$n" & 
-        "char** gEnv;$n" &
-        "N_CDECL(void, NimMain)(void) {$n" &
-        CommonMainBody & "}$n"
+    PreMainBody =
+      "\tsystemDatInit();$n" &
+      "\tsystemInit();$n" &
+      "$1" &
+      "$2" &
+      "$3" &
+      "$4"
+
+    MainProcs =
+      "\tPreMain();$n" &
+      "\tNimMain();$n"
+    
+    MainProcsWithResult =
+      MainProcs & "\treturn nim_program_result;$n"
+
+    PosixNimMain =
+      "int cmdCount;$n" &
+      "char** cmdLine;$n" &
+      "char** gEnv;$n" &
+      "N_CDECL(void, NimMain)(void) {$n$1}$n"
+  
     PosixCMain = "int main(int argc, char** args, char** env) {$n" &
-        "\tcmdLine = args;$n" & "\tcmdCount = argc;$n" & "\tgEnv = env;$n" &
-        "\tNimMain();$n" & "\treturn nim_program_result;$n" & "}$n"
+      "\tcmdLine = args;$n" & "\tcmdCount = argc;$n" & "\tgEnv = env;$n" &
+      MainProcsWithResult &
+      "}$n"
+  
     StandaloneCMain = "int main(void) {$n" &
-        "\tNimMain();$n" & 
-        "\treturn 0;$n" & "}$n"
-    WinNimMain = "N_CDECL(void, NimMain)(void) {$n" &
-        CommonMainBody & "}$n"
+      MainProcs &
+      "\treturn 0;$n" & "}$n"
+    
+    WinNimMain = "N_CDECL(void, NimMain)(void) {$n$1}$n"
+    
     WinCMain = "N_STDCALL(int, WinMain)(HINSTANCE hCurInstance, $n" &
-        "                        HINSTANCE hPrevInstance, $n" &
-        "                        LPSTR lpCmdLine, int nCmdShow) {$n" &
-        "\tNimMain();$n" & "\treturn nim_program_result;$n" & "}$n"
-    WinNimDllMain = "N_LIB_EXPORT N_CDECL(void, NimMain)(void) {$n" &
-        CommonMainBody & "}$n"
-    WinCDllMain = 
-        "BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, $n" &
-        "                    LPVOID lpvReserved) {$n" &
-          "\tif(fwdreason == DLL_PROCESS_ATTACH) NimMain();$n" &
-        "\treturn 1;$n" & "}$n"
+      "                        HINSTANCE hPrevInstance, $n" &
+      "                        LPSTR lpCmdLine, int nCmdShow) {$n" &
+      MainProcsWithResult & "}$n"
+  
+    WinNimDllMain = "N_LIB_EXPORT N_CDECL(void, NimMain)(void) {$n$1}$n"
+
+    WinCDllMain =
+      "BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, $n" &
+      "                    LPVOID lpvReserved) {$n" &
+      "\tif(fwdreason == DLL_PROCESS_ATTACH) {" & MainProcs & "}$n" &
+      "\treturn 1;$n}$n"
+
     PosixNimDllMain = WinNimDllMain
-    PosixCDllMain = 
-        "void NIM_POSIX_INIT NimMainInit(void) {$n" &
-        "\tNimMain();$n}$n"
+    
+    PosixCDllMain =
+      "void NIM_POSIX_INIT NimMainInit(void) {$n" &
+      MainProcs &
+      "}$n"
+
   var nimMain, otherMain: TFormatStr
   if platform.targetOS == osWindows and
       gGlobalOptions * {optGenGuiApp, optGenDynLib} != {}: 
@@ -1008,8 +1024,10 @@ proc genMainProc(m: BModule) =
                               platform.targetOS == osStandalone: "".toRope
                             else: ropecg(m, "\t#initStackBottom();$n")
   inc(m.labels)
-  appcg(m, m.s[cfsProcs], nimMain, [mainDatInit, initStackBottomCall,
-        gBreakpoints, mainModInit, toRope(m.labels)])
+  appcg(m, m.s[cfsProcs], "void PreMain() {$n" & PreMainBody & "}$n", [
+    mainDatInit, initStackBottomCall, gBreakpoints, otherModsInit])
+
+  appcg(m, m.s[cfsProcs], nimMain, [mainModInit, toRope(m.labels)])
   if optNoMain notin gGlobalOptions:
     appcg(m, m.s[cfsProcs], otherMain, [])
 
@@ -1030,10 +1048,14 @@ proc registerModuleToMain(m: PSym) =
                       "declare void $1() noinline$N", [init])
   appff(mainModProcs, "N_NOINLINE(void, $1)(void);$N",
                       "declare void $1() noinline$N", [datInit])
-  if not (sfSystemModule in m.flags):
-    appff(mainModInit, "\t$1();$n", "call void ()* $1$n", [init])
+  if sfSystemModule notin m.flags:
     appff(mainDatInit, "\t$1();$n", "call void ()* $1$n", [datInit])
-  
+    let initCall = ropeff("\t$1();$n", "call void ()* $1$n", [init])
+    if sfMainModule in m.flags:
+      app(mainModInit, initCall)
+    else:
+      app(otherModsInit, initCall)
+    
 proc genInitCode(m: BModule) = 
   var initname = getInitName(m.module)
   var prc = ropeff("N_NOINLINE(void, $1)(void) {$n", 
diff --git a/compiler/cgendata.nim b/compiler/cgendata.nim
index d72f9fa4d..9cd2c0d87 100644
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -114,7 +114,8 @@ type
     injectStmt*: PRope
 
 var
-  mainModProcs*, mainModInit*, mainDatInit*: PRope # parts of the main module
+  mainModProcs*, mainModInit*, otherModsInit*, mainDatInit*: PRope
+    # varuious parts of the main module
   gMapping*: PRope             # the generated mapping file (if requested)
   gModules*: seq[BModule] = @[] # list of all compiled modules
   gForwardedProcsCounter*: int = 0
diff --git a/compiler/evalffi.nim b/compiler/evalffi.nim
index 3b8ce0505..74f0663f3 100644
--- a/compiler/evalffi.nim
+++ b/compiler/evalffi.nim
@@ -87,7 +87,7 @@ proc mapType(t: ast.PType): ptr libffi.TType =
   of tyFloat, tyFloat64: result = addr libffi.type_double
   of tyFloat32: result = addr libffi.type_float
   of tyVar, tyPointer, tyPtr, tyRef, tyCString, tySequence, tyString, tyExpr,
-     tyStmt, tyTypeDesc, tyProc, tyArray, tyArrayConstr, tyNil:
+     tyStmt, tyTypeDesc, tyProc, tyArray, tyArrayConstr, tyStatic, tyNil:
     result = addr libffi.type_pointer
   of tyDistinct:
     result = mapType(t.sons[0])
diff --git a/compiler/evals.nim b/compiler/evals.nim
index b4ea973e8..151adf690 100644
--- a/compiler/evals.nim
+++ b/compiler/evals.nim
@@ -91,6 +91,7 @@ proc evalMacroCall*(c: PEvalContext, n, nOrig: PNode, sym: PSym): PNode
 proc evalAux(c: PEvalContext, n: PNode, flags: TEvalFlags): PNode
 
 proc raiseCannotEval(c: PEvalContext, info: TLineInfo): PNode =
+  if defined(debug) and gVerbosity >= 3: writeStackTrace()
   result = newNodeI(nkExceptBranch, info)
   # creating a nkExceptBranch without sons 
   # means that it could not be evaluated
@@ -263,8 +264,8 @@ proc getNullValue(typ: PType, info: TLineInfo): PNode =
     result = newNodeIT(nkUIntLit, info, t)
   of tyFloat..tyFloat128: 
     result = newNodeIt(nkFloatLit, info, t)
-  of tyVar, tyPointer, tyPtr, tyRef, tyCString, tySequence, tyString, tyExpr, 
-     tyStmt, tyTypeDesc, tyProc:
+  of tyVar, tyPointer, tyPtr, tyRef, tyCString, tySequence, tyString, tyExpr,
+     tyStmt, tyTypeDesc, tyStatic, tyProc:
     result = newNodeIT(nkNilLit, info, t)
   of tyObject: 
     result = newNodeIT(nkPar, info, t)
@@ -358,7 +359,7 @@ proc evalVar(c: PEvalContext, n: PNode): PNode =
 
 proc aliasNeeded(n: PNode, flags: TEvalFlags): bool = 
   result = efLValue in flags or n.typ == nil or 
-    n.typ.kind in {tyExpr, tyStmt, tyTypeDesc}
+    n.typ.kind in {tyExpr, tyStatic, tyStmt, tyTypeDesc}
 
 proc evalVariable(c: PStackFrame, sym: PSym, flags: TEvalFlags): PNode =
   # We need to return a node to the actual value,
@@ -905,17 +906,15 @@ proc evalParseStmt(c: PEvalContext, n: PNode): PNode =
   result = parseString(code.getStrValue, code.info.toFilename,
                        code.info.line.int)
   #result.typ = newType(tyStmt, c.module)
- 
-proc evalTypeTrait*(trait, operand: PNode, context: PSym): PNode =
-  InternalAssert operand.kind == nkSym
 
-  let typ = operand.sym.typ.skipTypes({tyTypeDesc})
+proc evalTypeTrait*(trait, operand: PNode, context: PSym): PNode =
+  let typ = operand.typ.skipTypes({tyTypeDesc})
   case trait.sym.name.s.normalize
   of "name":
     result = newStrNode(nkStrLit, typ.typeToString(preferName))
     result.typ = newType(tyString, context)
     result.info = trait.info
-  of "arity":    
+  of "arity":
     result = newIntNode(nkIntLit, typ.n.len-1)
     result.typ = newType(tyInt, context)
     result.info = trait.info
@@ -1329,7 +1328,7 @@ proc evalAux(c: PEvalContext, n: PNode, flags: TEvalFlags): PNode =
   if gNestedEvals <= 0: stackTrace(c, n.info, errTooManyIterations)
   case n.kind
   of nkSym: result = evalSym(c, n, flags)
-  of nkType..nkNilLit:
+  of nkType..nkNilLit, nkTypeOfExpr:
     # nkStrLit is VERY common in the traces, so we should avoid
     # the 'copyNode' here.
     result = n #.copyNode
diff --git a/compiler/jsgen.nim b/compiler/jsgen.nim
index c6b0b194f..b4e696d0a 100644
--- a/compiler/jsgen.nim
+++ b/compiler/jsgen.nim
@@ -129,8 +129,9 @@ proc mapType(typ: PType): TJSTypeKind =
      tyVarargs:
     result = etyObject
   of tyNil: result = etyNull
-  of tyGenericInst, tyGenericParam, tyGenericBody, tyGenericInvokation, tyNone, 
-     tyForward, tyEmpty, tyExpr, tyStmt, tyTypeDesc, tyTypeClasses: 
+  of tyGenericInst, tyGenericParam, tyGenericBody, tyGenericInvokation,
+     tyNone, tyFromExpr, tyForward, tyEmpty,
+     tyExpr, tyStmt, tyStatic, tyTypeDesc, tyTypeClasses:
     result = etyNone
   of tyProc: result = etyProc
   of tyCString: result = etyString
diff --git a/compiler/msgs.nim b/compiler/msgs.nim
index cc76f857d..d7944a182 100644
--- a/compiler/msgs.nim
+++ b/compiler/msgs.nim
@@ -93,6 +93,7 @@ type
     errNewSectionExpected, errWhitespaceExpected, errXisNoValidIndexFile, 
     errCannotRenderX, errVarVarTypeNotAllowed, errInstantiateXExplicitely,
     errOnlyACallOpCanBeDelegator, errUsingNoSymbol,
+    errDestructorNotGenericEnough,
     
     errXExpectsTwoArguments, 
     errXExpectsObjectTypes, errXcanNeverBeOfThisSubtype, errTooManyIterations, 
@@ -322,6 +323,8 @@ const
     errInstantiateXExplicitely: "instantiate '$1' explicitely",
     errOnlyACallOpCanBeDelegator: "only a call operator can be a delegator",
     errUsingNoSymbol: "'$1' is not a variable, constant or a proc name",
+    errDestructorNotGenericEnough: "Destructor signarue is too specific. " &
+                                   "A destructor must be associated will all instantiations of a generic type",
     errXExpectsTwoArguments: "\'$1\' expects two arguments", 
     errXExpectsObjectTypes: "\'$1\' expects object types",
     errXcanNeverBeOfThisSubtype: "\'$1\' can never be of this subtype", 
@@ -643,6 +646,8 @@ proc toFileLine*(info: TLineInfo): string {.inline.} =
 proc toFileLineCol*(info: TLineInfo): string {.inline.} =
   result = info.toFilename & "(" & $info.line & "," & $info.col & ")"
 
+template `$`*(info: TLineInfo): expr = toFileLineCol(info)
+
 proc `??`* (info: TLineInfo, filename: string): bool =
   # only for debugging purposes
   result = filename in info.toFilename
@@ -699,21 +704,20 @@ type
   TErrorHandling = enum doNothing, doAbort, doRaise
 
 proc handleError(msg: TMsgKind, eh: TErrorHandling, s: string) =
-  template maybeTrace =
+  template quit =
     if defined(debug) or gVerbosity >= 3 or msg == errInternal:
       writeStackTrace()
+    quit 1
 
   if msg >= fatalMin and msg <= fatalMax: 
-    maybeTrace()
-    quit(1)
+    quit()
   if msg >= errMin and msg <= errMax: 
-    maybeTrace()
     inc(gErrorCounter)
     options.gExitcode = 1'i8
     if gErrorCounter >= gErrorMax: 
-      quit(1)
+      quit()
     elif eh == doAbort and gCmd != cmdIdeTools:
-      quit(1)
+      quit()
     elif eh == doRaise:
       raiseRecoverableError(s)
 
diff --git a/compiler/options.nim b/compiler/options.nim
index f184deb69..9b0cbf0c9 100644
--- a/compiler/options.nim
+++ b/compiler/options.nim
@@ -158,8 +158,6 @@ var
 
 const oKeepVariableNames* = true
 
-const oUseLateInstantiation* = false
-
 proc mainCommandArg*: string =
   ## This is intended for commands like check or parse
   ## which will work on the main project file unless
diff --git a/compiler/parser.nim b/compiler/parser.nim
index b3a4e6963..e7a15c8ab 100644
--- a/compiler/parser.nim
+++ b/compiler/parser.nim
@@ -965,14 +965,18 @@ proc primary(p: var TParser, mode: TPrimaryMode): PNode =
   of tkTuple: result = parseTuple(p, mode == pmTypeDef)
   of tkProc: result = parseProcExpr(p, mode notin {pmTypeDesc, pmTypeDef})
   of tkIterator:
-    if mode in {pmTypeDesc, pmTypeDef}:
-      result = parseProcExpr(p, false)
-      result.kind = nkIteratorTy
+    when true:
+      if mode in {pmTypeDesc, pmTypeDef}:
+        result = parseProcExpr(p, false)
+        result.kind = nkIteratorTy
+      else:
+        # no anon iterators for now:
+        parMessage(p, errExprExpected, p.tok)
+        getTok(p)  # we must consume a token here to prevend endless loops!
+        result = ast.emptyNode
     else:
-      # no anon iterators for now:
-      parMessage(p, errExprExpected, p.tok)
-      getTok(p)  # we must consume a token here to prevend endless loops!
-      result = ast.emptyNode
+      result = parseProcExpr(p, mode notin {pmTypeDesc, pmTypeDef})
+      result.kind = nkIteratorTy
   of tkEnum:
     if mode == pmTypeDef:
       result = parseEnum(p)
@@ -995,9 +999,13 @@ proc primary(p: var TParser, mode: TPrimaryMode): PNode =
     getTokNoInd(p)
     addSon(result, primary(p, pmNormal))
   of tkStatic:
-    result = newNodeP(nkStaticExpr, p)
+    let info = parLineInfo(p)
     getTokNoInd(p)
-    addSon(result, primary(p, pmNormal))
+    let next = primary(p, pmNormal)
+    if next.kind == nkBracket and next.sonsLen == 1:
+      result = newNode(nkStaticTy, info, @[next.sons[0]])
+    else:
+      result = newNode(nkStaticExpr, info, @[next])
   of tkBind:
     result = newNodeP(nkBind, p)
     getTok(p)
diff --git a/compiler/procfind.nim b/compiler/procfind.nim
index 51bd7b937..eb0cbca3f 100644
--- a/compiler/procfind.nim
+++ b/compiler/procfind.nim
@@ -25,12 +25,12 @@ proc equalGenericParams(procA, procB: PNode): bool =
     let a = procA.sons[i].sym
     let b = procB.sons[i].sym
     if a.name.id != b.name.id or
-        not sameTypeOrNil(a.typ, b.typ, {TypeDescExactMatch}): return
+        not sameTypeOrNil(a.typ, b.typ, {ExactTypeDescValues}): return
     if a.ast != nil and b.ast != nil:
       if not exprStructuralEquivalent(a.ast, b.ast): return
   result = true
 
-proc searchForProc*(c: PContext, scope: PScope, fn: PSym): PSym =
+proc searchForProcOld*(c: PContext, scope: PScope, fn: PSym): PSym =
   # Searchs for a forward declaration or a "twin" symbol of fn
   # in the symbol table. If the parameter lists are exactly
   # the same the sym in the symbol table is returned, else nil.
@@ -63,6 +63,30 @@ proc searchForProc*(c: PContext, scope: PScope, fn: PSym): PSym =
           nil
       result = nextIdentIter(it, scope.symbols)
 
+proc searchForProcNew(c: PContext, scope: PScope, fn: PSym): PSym =
+  const flags = {ExactGenericParams, ExactTypeDescValues,
+                 ExactConstraints, IgnoreCC}
+
+  var it: TIdentIter
+  result = initIdentIter(it, scope.symbols, fn.name)
+  while result != nil:
+    if result.kind in skProcKinds and
+       sameType(result.typ, fn.typ, flags): return
+
+    result = nextIdentIter(it, scope.symbols)
+  
+  return nil
+
+proc searchForProc*(c: PContext, scope: PScope, fn: PSym): PSym =
+  result = searchForProcNew(c, scope, fn)
+  when false:
+    let old = searchForProcOld(c, scope, fn)
+    if old != result:
+      echo "Mismatch in searchForProc: ", fn.info
+      debug fn.typ
+      debug if result != nil: result.typ else: nil
+      debug if old != nil: old.typ else: nil
+ 
 when false:
   proc paramsFitBorrow(child, parent: PNode): bool = 
     var length = sonsLen(child)
diff --git a/compiler/ropes.nim b/compiler/ropes.nim
index 2be40524a..fcf5dd202 100644
--- a/compiler/ropes.nim
+++ b/compiler/ropes.nim
@@ -282,13 +282,16 @@ proc ropef(frmt: TFormatStr, args: varargs[PRope]): PRope =
       app(result, substr(frmt, start, i - 1))
   assert(ropeInvariant(result))
 
-{.push stack_trace: off, line_trace: off.}
-proc `~`*(r: expr[string]): PRope =
-  # this is the new optimized "to rope" operator
-  # the mnemonic is that `~` looks a bit like a rope :)
-  var r {.global.} = r.ropef
-  return r
-{.pop.}
+when true:
+  template `~`*(r: string): PRope = r.ropef
+else:
+  {.push stack_trace: off, line_trace: off.}
+  proc `~`*(r: static[string]): PRope =
+    # this is the new optimized "to rope" operator
+    # the mnemonic is that `~` looks a bit like a rope :)
+    var r {.global.} = r.ropef
+    return r
+  {.pop.}
 
 proc appf(c: var PRope, frmt: TFormatStr, args: varargs[PRope]) = 
   app(c, ropef(frmt, args))
diff --git a/compiler/sem.nim b/compiler/sem.nim
index a5b72e2b8..b53e7335c 100644
--- a/compiler/sem.nim
+++ b/compiler/sem.nim
@@ -158,6 +158,16 @@ 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
+
+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)
@@ -169,9 +179,39 @@ when false:
         result = newSymNode(getSysSym"void")
       else:
         result.typ = makeTypeDesc(c, result.typ)
-
+    
     result.handleIsOperator = proc (n: PNode): PNode =
-      result = IsOpImpl(c, n)
+      result = isOpImpl(c, n)
+
+proc fixupTypeAfterEval(c: PContext, evaluated, eOrig: PNode): PNode =
+  # recompute the types as 'eval' isn't guaranteed to construct types nor
+  # that the types are sound:
+  result = semExprWithType(c, evaluated)
+  #result = fitNode(c, e.typ, result) inlined with special case:
+  let arg = result
+  result = indexTypesMatch(c, eOrig.typ, arg.typ, arg)
+  if result == nil:
+    result = arg
+    # for 'tcnstseq' we support [] to become 'seq'
+    if eOrig.typ.skipTypes(abstractInst).kind == tySequence and 
+       arg.typ.skipTypes(abstractInst).kind == tyArrayConstr:
+      arg.typ = eOrig.typ
+
+proc tryConstExpr(c: PContext, n: PNode): PNode =
+  var e = semExprWithType(c, n)
+  if e == nil: return
+
+  result = getConstExpr(c.module, e)
+  if result != nil: return
+
+  try:
+    result = evalConstExpr(c.module, e)
+    if result == nil or result.kind == nkEmpty:
+      return nil
+
+    result = fixupTypeAfterEval(c, result, e)
+  except:
+    return nil
 
 proc semConstExpr(c: PContext, n: PNode): PNode =
   var e = semExprWithType(c, n)
@@ -191,18 +231,7 @@ proc semConstExpr(c: PContext, n: PNode): PNode =
       # error correction:
       result = e
     else:
-      # recompute the types as 'eval' isn't guaranteed to construct types nor
-      # that the types are sound:
-      result = semExprWithType(c, result)
-      #result = fitNode(c, e.typ, result) inlined with special case:
-      let arg = result
-      result = indexTypesMatch(c, e.typ, arg.typ, arg)
-      if result == nil:
-        result = arg
-        # for 'tcnstseq' we support [] to become 'seq'
-        if e.typ.skipTypes(abstractInst).kind == tySequence and 
-           arg.typ.skipTypes(abstractInst).kind == tyArrayConstr:
-          arg.typ = e.typ
+      result = fixupTypeAfterEval(c, result, e)
 
 include hlo, seminst, semcall
 
@@ -264,6 +293,14 @@ proc semConstBoolExpr(c: PContext, n: PNode): PNode =
     localError(n.info, errConstExprExpected)
     result = nn
 
+type
+  TSemGenericFlag = enum
+    withinBind, withinTypeDesc, withinMixin
+  TSemGenericFlags = set[TSemGenericFlag]
+
+proc semGenericStmt(c: PContext, n: PNode, flags: TSemGenericFlags,
+                    ctx: var TIntSet): PNode
+
 include semtypes, semtempl, semgnrc, semstmts, semexprs
 
 proc addCodeForGenerics(c: PContext, n: PNode) =
@@ -282,6 +319,7 @@ proc myOpen(module: PSym): PPassContext =
   c.semConstExpr = semConstExpr
   c.semExpr = semExpr
   c.semTryExpr = tryExpr
+  c.semTryConstExpr = tryConstExpr
   c.semOperand = semOperand
   c.semConstBoolExpr = semConstBoolExpr
   c.semOverloadedCall = semOverloadedCall
diff --git a/compiler/semcall.nim b/compiler/semcall.nim
index 6140d8311..5990f2e96 100644
--- a/compiler/semcall.nim
+++ b/compiler/semcall.nim
@@ -47,14 +47,14 @@ proc pickBestCandidate(c: PContext, headSymbol: PNode,
   var z: TCandidate
   
   if sym == nil: return
-  initCandidate(best, sym, initialBinding, symScope)
-  initCandidate(alt, sym, initialBinding, symScope)
+  initCandidate(c, best, sym, initialBinding, symScope)
+  initCandidate(c, alt, sym, initialBinding, symScope)
   best.state = csNoMatch
   
   while sym != nil:
     if sym.kind in filter:
       determineType(c, sym)
-      initCandidate(z, sym, initialBinding, o.lastOverloadScope)
+      initCandidate(c, z, sym, initialBinding, o.lastOverloadScope)
       z.calleeSym = sym
       matches(c, n, orig, z)
       if errors != nil:
@@ -199,15 +199,15 @@ proc instGenericConvertersSons*(c: PContext, n: PNode, x: TCandidate) =
 
 proc indexTypesMatch(c: PContext, f, a: PType, arg: PNode): PNode = 
   var m: TCandidate
-  initCandidate(m, f)
-  result = paramTypesMatch(c, m, f, a, arg, nil)
+  initCandidate(c, m, f)
+  result = paramTypesMatch(m, f, a, arg, nil)
   if m.genericConverter and result != nil:
     instGenericConvertersArg(c, result, m)
 
 proc convertTo*(c: PContext, f: PType, n: PNode): PNode = 
   var m: TCandidate
-  initCandidate(m, f)
-  result = paramTypesMatch(c, m, f, n.typ, n, nil)
+  initCandidate(c, m, f)
+  result = paramTypesMatch(m, f, n.typ, n, nil)
   if m.genericConverter and result != nil:
     instGenericConvertersArg(c, result, m)
 
@@ -243,9 +243,9 @@ proc explicitGenericInstError(n: PNode): PNode =
   result = n
 
 proc explicitGenericSym(c: PContext, n: PNode, s: PSym): PNode =
-  var x: TCandidate
-  initCandidate(x, s, n)
-  var newInst = generateInstance(c, s, x.bindings, n.info)
+  var m: TCandidate
+  initCandidate(c, m, s, n)
+  var newInst = generateInstance(c, s, m.bindings, n.info)
   markUsed(n, s)
   result = newSymNode(newInst, n.info)
 
diff --git a/compiler/semdata.nim b/compiler/semdata.nim
index 924224fee..980abb865 100644
--- a/compiler/semdata.nim
+++ b/compiler/semdata.nim
@@ -75,6 +75,7 @@ type
     semExpr*: proc (c: PContext, n: PNode, flags: TExprFlags = {}): PNode {.nimcall.}
     semTryExpr*: proc (c: PContext, n: PNode,flags: TExprFlags = {},
                        bufferErrors = false): PNode {.nimcall.}
+    semTryConstExpr*: proc (c: PContext, n: PNode): 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,
@@ -213,14 +214,40 @@ proc makeTypeSymNode*(c: PContext, typ: PType, info: TLineInfo): PNode =
   let sym = newSym(skType, idAnon, getCurrOwner(), info).linkTo(typedesc)
   return newSymNode(sym, info)
 
-proc newTypeS(kind: TTypeKind, c: PContext): PType = 
-  result = newType(kind, getCurrOwner())
+proc makeTypeFromExpr*(c: PContext, n: PNode): PType =
+  result = newTypeS(tyFromExpr, c)
+  result.n = n
 
 proc newTypeWithSons*(c: PContext, kind: TTypeKind,
                       sons: seq[PType]): PType =
   result = newType(kind, getCurrOwner())
   result.sons = sons
 
+proc makeStaticExpr*(c: PContext, n: PNode): PNode =
+  result = newNodeI(nkStaticExpr, n.info)
+  result.sons = @[n]
+  result.typ = newTypeWithSons(c, tyStatic, @[n.typ])
+
+proc makeAndType*(c: PContext, t1, t2: PType): PType =
+  result = newTypeS(tyAnd, c)
+  result.sons = @[t1, t2]
+  propagateToOwner(result, t1)
+  propagateToOwner(result, t2)
+
+proc makeOrType*(c: PContext, t1, t2: PType): PType =
+  result = newTypeS(tyOr, c)
+  result.sons = @[t1, t2]
+  propagateToOwner(result, t1)
+  propagateToOwner(result, t2)
+
+proc makeNotType*(c: PContext, t1: PType): PType =
+  result = newTypeS(tyNot, c)
+  result.sons = @[t1]
+  propagateToOwner(result, t1)
+
+proc newTypeS(kind: TTypeKind, c: PContext): PType =
+  result = newType(kind, getCurrOwner())
+
 proc errorType*(c: PContext): PType =
   ## creates a type representing an error state
   result = newTypeS(tyError, c)
diff --git a/compiler/semdestruct.nim b/compiler/semdestruct.nim
index 6965b36bc..9dbbf2940 100644
--- a/compiler/semdestruct.nim
+++ b/compiler/semdestruct.nim
@@ -9,6 +9,7 @@
 
 ## This module implements destructors.
 
+# included from sem.nim
 
 # special marker values that indicates that we are
 # 1) AnalyzingDestructor: currently analyzing the type for destructor 
@@ -25,10 +26,22 @@ var
   destructorPragma = newIdentNode(getIdent"destructor", unknownLineInfo())
   rangeDestructorProc*: PSym
 
-proc instantiateDestructor(c: PContext, typ: PType): bool
+proc instantiateDestructor(c: PContext, typ: PType): PType
 
 proc doDestructorStuff(c: PContext, s: PSym, n: PNode) =
-  let t = s.typ.sons[1].skipTypes({tyVar})
+  var t = s.typ.sons[1].skipTypes({tyVar})
+  if t.kind == tyGenericInvokation:
+    for i in 1 .. <t.sonsLen:
+      if t.sons[i].kind != tyGenericParam:
+        localError(n.info, errDestructorNotGenericEnough)
+        return
+    t = t.base
+  elif t.kind == tyCompositeTypeClass:
+    t = t.base
+    if t.kind != tyGenericBody:
+      localError(n.info, errDestructorNotGenericEnough)
+      return
+  
   t.destructor = s
   # automatically insert calls to base classes' destructors
   if n.sons[bodyPos].kind != nkEmpty:
@@ -36,15 +49,17 @@ proc doDestructorStuff(c: PContext, s: PSym, n: PNode) =
       # when inheriting directly from object
       # there will be a single nil son
       if t.sons[i] == nil: continue
-      if instantiateDestructor(c, t.sons[i]):
+      let destructableT = instantiateDestructor(c, t.sons[i])
+      if destructableT != nil:
         n.sons[bodyPos].addSon(newNode(nkCall, t.sym.info, @[
-            useSym(t.sons[i].destructor),
+            useSym(destructableT.destructor),
             n.sons[paramsPos][1][0]]))
 
 proc destroyField(c: PContext, field: PSym, holder: PNode): PNode =
-  if instantiateDestructor(c, field.typ):
+  let destructableT = instantiateDestructor(c, field.typ)
+  if destructableT != nil:
     result = newNode(nkCall, field.info, @[
-      useSym(field.typ.destructor),
+      useSym(destructableT.destructor),
       newNode(nkDotExpr, field.info, @[holder, useSym(field)])])
 
 proc destroyCase(c: PContext, n: PNode, holder: PNode): PNode =
@@ -105,26 +120,35 @@ proc generateDestructor(c: PContext, t: PType): PNode =
   # base classes' destructors will be automatically called by
   # semProcAux for both auto-generated and user-defined destructors
 
-proc instantiateDestructor(c: PContext, typ: PType): bool =
-  # returns true if the type already had a user-defined
-  # destructor or if the compiler generated a default
-  # member-wise one
-  var t = skipTypes(typ, {tyConst, tyMutable})
+proc instantiateDestructor(c: PContext, typ: PType): PType =
+  # returns nil if a variable of type `typ` doesn't require a
+  # destructor. Otherwise, returns the type, which holds the 
+  # destructor that must be used for the varialbe.
+  # The destructor is either user-defined or automatically
+  # generated by the compiler in a member-wise fashion.
+  var t = skipTypes(typ, {tyConst, tyMutable}).skipGenericAlias
+  let typeHoldingUserDefinition = if t.kind == tyGenericInst: t.base
+                                  else: t
   
-  if t.destructor != nil:
+  if typeHoldingUserDefinition.destructor != nil:
     # XXX: This is not entirely correct for recursive types, but we need
     # it temporarily to hide the "destroy is already defined" problem
-    return t.destructor notin [analyzingDestructor, destructorIsTrivial]
+    if typeHoldingUserDefinition.destructor notin
+        [analyzingDestructor, destructorIsTrivial]:
+      return typeHoldingUserDefinition
+    else:
+      return nil
   
+  t = t.skipTypes({tyGenericInst})
   case t.kind
   of tySequence, tyArray, tyArrayConstr, tyOpenArray, tyVarargs:
-    if instantiateDestructor(c, t.sons[0]):
+    if instantiateDestructor(c, t.sons[0]) != nil:
       if rangeDestructorProc == nil:
         rangeDestructorProc = searchInScopes(c, getIdent"nimDestroyRange")
       t.destructor = rangeDestructorProc
-      return true
+      return t
     else:
-      return false
+      return nil
   of tyTuple, tyObject:
     t.destructor = analyzingDestructor
     let generated = generateDestructor(c, t)
@@ -139,21 +163,21 @@ proc instantiateDestructor(c: PContext, typ: PType): bool =
           emptyNode,
           newNode(nkIdentDefs, i, @[
             newIdentNode(destructorParam, i),
-            useSym(t.sym),
+            symNodeFromType(c, makeVarType(c, t), t.sym.info),
             emptyNode]),
           ]),
         newNode(nkPragma, i, @[destructorPragma]),
         emptyNode,
         generated
         ])
-      discard semProc(c, fullDef)
-      internalAssert t.destructor != nil
-      return true
+      let semantizedDef = semProc(c, fullDef)
+      t.destructor = semantizedDef[namePos].sym
+      return t
     else:
       t.destructor = destructorIsTrivial
-      return false
+      return nil
   else:
-    return false
+    return nil
 
 proc insertDestructors(c: PContext,
                        varSection: PNode): tuple[outer, inner: PNode] =
@@ -179,9 +203,11 @@ proc insertDestructors(c: PContext,
       varId = varSection[j][0]
       varTyp = varId.sym.typ
       info = varId.info
-
-    if varTyp != nil and instantiateDestructor(c, varTyp) and 
-        sfGlobal notin varId.sym.flags:
+    
+    if varTyp == nil or sfGlobal in varId.sym.flags: continue
+    let destructableT = instantiateDestructor(c, varTyp)
+    
+    if destructableT != nil:
       var tryStmt = newNodeI(nkTryStmt, info)
 
       if j < totalVars - 1:
@@ -198,11 +224,11 @@ proc insertDestructors(c: PContext,
       else:
         result.inner = newNodeI(nkStmtList, info)
         tryStmt.addSon(result.inner)
-
+    
       tryStmt.addSon(
         newNode(nkFinally, info, @[
           semStmt(c, newNode(nkCall, info, @[
-            useSym(varTyp.destructor),
+            useSym(destructableT.destructor),
             useSym(varId.sym)]))]))
 
       result.outer = newNodeI(nkStmtList, info)
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index 082ee7583..1f7803c95 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -102,7 +102,7 @@ proc semSym(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
     # if a proc accesses a global variable, it is not side effect free:
     if sfGlobal in s.flags:
       incl(c.p.owner.flags, sfSideEffect)
-    elif s.kind == skParam and s.typ.kind == tyExpr and s.typ.n != nil:
+    elif s.kind == skParam and s.typ.kind == tyStatic and s.typ.n != nil:
       # XXX see the hack in sigmatch.nim ...
       return s.typ.n
     result = newSymNode(s, n.info)
@@ -111,7 +111,7 @@ proc semSym(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
     # var len = 0 # but won't be called
     # genericThatUsesLen(x) # marked as taking a closure?
   of skGenericParam:
-    if s.typ.kind == tyExpr:
+    if s.typ.kind == tyStatic:
       result = newSymNode(s, n.info)
       result.typ = s.typ
     elif s.ast != nil:
@@ -142,7 +142,7 @@ proc checkConversionBetweenObjects(castDest, src: PType): TConvStatus =
 const 
   IntegralTypes = {tyBool, tyEnum, tyChar, tyInt..tyUInt64}
 
-proc checkConvertible(castDest, src: PType): TConvStatus =
+proc checkConvertible(c: PContext, castDest, src: PType): TConvStatus =
   result = convOK
   if sameType(castDest, src) and castDest.sym == src.sym:
     # don't annoy conversions that may be needed on another processor:
@@ -163,7 +163,7 @@ proc checkConvertible(castDest, src: PType): TConvStatus =
     # accept conversion between integral types
   else:
     # we use d, s here to speed up that operation a bit:
-    case cmpTypes(d, s)
+    case cmpTypes(c, d, s)
     of isNone, isGeneric:
       if not compareTypes(castDest, src, dcEqIgnoreDistinct):
         result = convNotLegal
@@ -202,7 +202,7 @@ proc semConv(c: PContext, n: PNode): PNode =
   var op = result.sons[1]
   
   if not isSymChoice(op):
-    let status = checkConvertible(result.typ, op.typ)
+    let status = checkConvertible(c, result.typ, op.typ)
     case status
     of convOK: nil
     of convNotNeedeed:
@@ -213,7 +213,7 @@ proc semConv(c: PContext, n: PNode): PNode =
   else:
     for i in countup(0, sonsLen(op) - 1):
       let it = op.sons[i]
-      let status = checkConvertible(result.typ, it.typ)
+      let status = checkConvertible(c, result.typ, it.typ)
       if status == convOK:
         markUsed(n, it.sym)
         markIndirect(c, it.sym)
@@ -231,7 +231,7 @@ proc semCast(c: PContext, n: PNode): PNode =
   if not isCastable(result.typ, result.sons[1].typ): 
     localError(result.info, errExprCannotBeCastedToX, 
                typeToString(result.typ))
-  
+
 proc semLowHigh(c: PContext, n: PNode, m: TMagic): PNode = 
   const 
     opToStr: array[mLow..mHigh, string] = ["low", "high"]
@@ -239,7 +239,7 @@ proc semLowHigh(c: PContext, n: PNode, m: TMagic): PNode =
     localError(n.info, errXExpectsTypeOrValue, opToStr[m])
   else: 
     n.sons[1] = semExprWithType(c, n.sons[1], {efDetermineType})
-    var typ = skipTypes(n.sons[1].typ, abstractVarRange)
+    var typ = skipTypes(n.sons[1].typ, abstractVarRange+{tyTypeDesc})
     case typ.kind
     of tySequence, tyString, tyOpenArray, tyVarargs: 
       n.typ = getSysType(tyInt)
@@ -249,8 +249,10 @@ proc semLowHigh(c: PContext, n: PNode, m: TMagic): PNode =
       # do not skip the range!
       n.typ = n.sons[1].typ.skipTypes(abstractVar)
     of tyGenericParam:
-      # leave it for now, it will be resolved in semtypinst
-      n.typ = getSysType(tyInt)
+      # prepare this for resolving in semtypinst:
+      # we must use copyTree here in order to avoid creating a cycle
+      # that could easily turn into an infinite recursion in semtypinst
+      n.typ = makeTypeFromExpr(c, n.copyTree)
     else:
       localError(n.info, errInvalidArgForX, opToStr[m])
   result = n
@@ -301,7 +303,7 @@ proc semOf(c: PContext, n: PNode): PNode =
 
 proc isOpImpl(c: PContext, n: PNode): PNode =
   internalAssert n.sonsLen == 3 and
-    n[1].typ != nil and
+    n[1].typ != nil and n[1].typ.kind == tyTypeDesc and
     n[2].kind in {nkStrLit..nkTripleStrLit, nkType}
   
   let t1 = n[1].typ.skipTypes({tyTypeDesc})
@@ -324,15 +326,15 @@ proc isOpImpl(c: PContext, n: PNode): PNode =
     case t2.kind
     of tyTypeClasses:
       var m: TCandidate
-      initCandidate(m, t2)
+      initCandidate(c, m, t2)
       match = matchUserTypeClass(c, m, emptyNode, t2, t1) != nil
     of tyOrdinal:
       var m: TCandidate
-      initCandidate(m, t2)
+      initCandidate(c, m, t2)
       match = isOrdinalType(t1)
     of tySequence, tyArray, tySet:
       var m: TCandidate
-      initCandidate(m, t2)
+      initCandidate(c, m, t2)
       match = typeRel(m, t2, t1) != isNone
     else:
       match = sameType(t1, t2)
@@ -668,6 +670,7 @@ proc semOverloadedCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
   else:
     result = semOverloadedCall(c, n, nOrig, 
       {skProc, skMethod, skConverter, skMacro, skTemplate})
+ 
   if result != nil:
     if result.sons[0].kind != nkSym: 
       internalError("semOverloadedCallAnalyseEffects")
@@ -706,7 +709,7 @@ proc semIndirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
   if t != nil and t.kind == tyProc:
     # This is a proc variable, apply normal overload resolution
     var m: TCandidate
-    initCandidate(m, t)
+    initCandidate(c, m, t)
     matches(c, n, nOrig, m)
     if m.state != csMatch:
       if c.inCompilesContext > 0:
@@ -939,7 +942,7 @@ proc builtinFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
         let tParam = tbody.sons[s]
         if tParam.sym.name == i:
           let rawTyp = ty.sons[s + 1]
-          if rawTyp.kind == tyExpr:
+          if rawTyp.kind == tyStatic:
             return rawTyp.n
           else:
             let foundTyp = makeTypeDesc(c, rawTyp)
@@ -1163,8 +1166,8 @@ proc semAsgn(c: PContext, n: PNode): PNode =
         if lhsIsResult: {efAllowDestructor} else: {})
     if lhsIsResult:
       n.typ = enforceVoidContext
-      if lhs.sym.typ.kind == tyGenericParam:
-        if matchTypeClass(lhs.typ, rhs.typ):
+      if lhs.sym.typ.isMetaType and lhs.sym.typ.kind != tyTypeDesc:
+        if cmpTypes(c, lhs.typ, rhs.typ) == isGeneric:
           internalAssert c.p.resultSym != nil
           lhs.typ = rhs.typ
           c.p.resultSym.typ = rhs.typ
@@ -1884,7 +1887,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
   of nkBind:
     message(n.info, warnDeprecated, "bind")
     result = semExpr(c, n.sons[0], flags)
-  of nkTypeOfExpr, nkTupleTy, nkRefTy..nkEnumTy:
+  of nkTypeOfExpr, nkTupleTy, nkRefTy..nkEnumTy, nkStaticTy:
     var typ = semTypeNode(c, n, nil).skipTypes({tyTypeDesc})
     result.typ = makeTypeDesc(c, typ)
     #result = symNodeFromType(c, typ, n.info)
@@ -1945,7 +1948,9 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
       # type parameters: partial generic specialization
       n.sons[0] = semSymGenericInstantiation(c, n.sons[0], s)
       result = explicitGenericInstantiation(c, n, s)
-    else: 
+    elif s != nil and s.kind in {skType}:
+      result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
+    else:
       result = semArrayAccess(c, n, flags)
   of nkCurlyExpr:
     result = semExpr(c, buildOverloadedSubscripts(n, getIdent"{}"), flags)
diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index 731085c3a..1d03e6888 100644
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -230,6 +230,7 @@ discard """
 """
 
 proc evalIs(n, a: PNode): PNode =
+  # XXX: This should use the standard isOpImpl
   internalAssert a.kind == nkSym and a.sym.kind == skType
   internalAssert n.sonsLen == 3 and
     n[2].kind in {nkStrLit..nkTripleStrLit, nkType}
@@ -251,7 +252,7 @@ proc evalIs(n, a: PNode): PNode =
   else:
     # XXX semexprs.isOpImpl is slightly different and requires a context. yay.
     let t2 = n[2].typ
-    var match = if t2.kind == tyTypeClass: matchTypeClass(t2, t1)
+    var match = if t2.kind == tyTypeClass: true
                 else: sameType(t1, t2)
     result = newIntNode(nkIntLit, ord(match))
   result.typ = n.typ
@@ -612,9 +613,10 @@ proc getConstExpr(m: PSym, n: PNode): PNode =
     of skType:
       result = newSymNodeTypeDesc(s, n.info)
     of skGenericParam:
-      if s.typ.kind == tyExpr:
-        result = s.typ.n
-        result.typ = s.typ.sons[0]
+      if s.typ.kind == tyStatic:
+        if s.typ.n != nil:
+          result = s.typ.n
+          result.typ = s.typ.sons[0]
       else:
         result = newSymNodeTypeDesc(s, n.info)
     else: discard
diff --git a/compiler/semgnrc.nim b/compiler/semgnrc.nim
index 9f477492c..b40e86cbf 100644
--- a/compiler/semgnrc.nim
+++ b/compiler/semgnrc.nim
@@ -17,11 +17,6 @@
 
 # included from sem.nim
 
-type
-  TSemGenericFlag = enum
-    withinBind, withinTypeDesc, withinMixin
-  TSemGenericFlags = set[TSemGenericFlag]
-
 proc getIdentNode(n: PNode): PNode =
   case n.kind
   of nkPostfix: result = getIdentNode(n.sons[1])
@@ -31,8 +26,6 @@ proc getIdentNode(n: PNode): PNode =
     illFormedAst(n)
     result = n
   
-proc semGenericStmt(c: PContext, n: PNode, flags: TSemGenericFlags,
-                    ctx: var TIntSet): PNode
 proc semGenericStmtScope(c: PContext, n: PNode, 
                          flags: TSemGenericFlags,
                          ctx: var TIntSet): PNode = 
diff --git a/compiler/seminst.nim b/compiler/seminst.nim
index 1025457fd..8faf1d21a 100644
--- a/compiler/seminst.nim
+++ b/compiler/seminst.nim
@@ -20,7 +20,7 @@ proc instantiateGenericParamList(c: PContext, n: PNode, pt: TIdTable,
     if a.kind != nkSym: 
       internalError(a.info, "instantiateGenericParamList; no symbol")
     var q = a.sym
-    if q.typ.kind notin {tyTypeDesc, tyGenericParam, tyExpr}+tyTypeClasses:
+    if q.typ.kind notin {tyTypeDesc, tyGenericParam, tyStatic}+tyTypeClasses:
       continue
     var s = newSym(skType, q.name, getCurrOwner(), q.info)
     s.flags = s.flags + {sfUsed, sfFromGeneric}
@@ -47,7 +47,7 @@ proc sameInstantiation(a, b: TInstantiation): bool =
   if a.concreteTypes.len == b.concreteTypes.len:
     for i in 0..a.concreteTypes.high:
       if not compareTypes(a.concreteTypes[i], b.concreteTypes[i],
-                          flags = {TypeDescExactMatch}): return
+                          flags = {ExactTypeDescValues}): return
     result = true
 
 proc genericCacheGet(genericSym: PSym, entry: TInstantiation): PSym =
@@ -131,139 +131,25 @@ proc sideEffectsCheck(c: PContext, s: PSym) =
       s.ast.sons[genericParamsPos].kind == nkEmpty:
     c.threadEntries.add(s)
 
-proc lateInstantiateGeneric(c: PContext, invocation: PType, info: TLineInfo): PType =
-  internalAssert invocation.kind == tyGenericInvokation
-  
-  let cacheHit = searchInstTypes(invocation)
-  if cacheHit != nil:
-    result = cacheHit
-  else:
-    let s = invocation.sons[0].sym
-    let oldScope = c.currentScope
-    c.currentScope = s.typScope
-    openScope(c)
-    pushInfoContext(info)
-    for i in 0 .. <s.typ.n.sons.len:
-      let genericParam = s.typ.n[i].sym
-      let symKind = if genericParam.typ.kind == tyExpr: skConst
-                    else: skType
-
-      var boundSym = newSym(symKind, s.typ.n[i].sym.name, s, info)
-      boundSym.typ = invocation.sons[i+1].skipTypes({tyExpr})
-      boundSym.ast = invocation.sons[i+1].n
-      addDecl(c, boundSym)
-    # XXX: copyTree would have been unnecessary here if semTypeNode
-    # didn't modify its input parameters. Currently, it does modify
-    # at least the record lists of the passed object and tuple types
-    var instantiated = semTypeNode(c, copyTree(s.ast[2]), nil)
-    popInfoContext()
-    closeScope(c)
-    c.currentScope = oldScope
-    if instantiated != nil:
-      result = invocation
-      result.kind = tyGenericInst
-      result.sons.add instantiated
-      cacheTypeInst result
-
-proc instGenericContainer(c: PContext, info: TLineInfo, header: PType): PType =
-  when oUseLateInstantiation:
-    lateInstantiateGeneric(c, header, info)
-  else:
-    var cl: TReplTypeVars
-    initIdTable(cl.symMap)
-    initIdTable(cl.typeMap)
-    cl.info = info
-    cl.c = c
-    result = replaceTypeVarsT(cl, header)
+proc instGenericContainer(c: PContext, info: TLineInfo, header: PType,
+                          allowMetaTypes = false): PType =
+  var cl: TReplTypeVars
+  initIdTable(cl.symMap)
+  initIdTable(cl.typeMap)
+  initIdTable(cl.localCache)
+  cl.info = info
+  cl.c = c
+  cl.allowMetaTypes = allowMetaTypes
+  result = replaceTypeVarsT(cl, header)
 
 proc instGenericContainer(c: PContext, n: PNode, header: PType): PType =
   result = instGenericContainer(c, n.info, header)
 
-proc fixupProcType(c: PContext, genericType: PType,
-                   inst: TInstantiation): PType =
-  # XXX: This is starting to look suspiciously like ReplaceTypeVarsT
-  # there are few apparent differences, but maybe the code could be
-  # moved over.
-  # * the code here uses the new genericSym.position property when
-  #   doing lookups. 
-  # * the handling of tyTypeDesc seems suspicious in ReplaceTypeVarsT
-  #   typedesc params were previously handled in the second pass of
-  #   semParamList
-  # * void (nkEmpty) params doesn't seem to be stripped in ReplaceTypeVarsT
-  result = genericType
-  if result == nil: return
-
-  case genericType.kind
-  of tyGenericParam, tyTypeClasses:
-    result = inst.concreteTypes[genericType.sym.position]
-  of tyTypeDesc:
-    result = inst.concreteTypes[genericType.sym.position]
-    if tfUnresolved in genericType.flags:
-      result = result.sons[0]
-  of tyExpr:
-    result = inst.concreteTypes[genericType.sym.position]
-  of tyOpenArray, tyArray, tySet, tySequence, tyTuple, tyProc,
-     tyPtr, tyVar, tyRef, tyOrdinal, tyRange, tyVarargs:
-    if genericType.sons == nil: return
-    var head = 0
-    for i in 0 .. <genericType.sons.len:
-      let origType = genericType.sons[i]
-      var changed = fixupProcType(c, origType, inst)
-      if changed != genericType.sons[i]:
-        var changed = changed.skipIntLit
-        if result == genericType:
-          # the first detected change initializes the result
-          result = copyType(genericType, genericType.owner, false)
-          if genericType.n != nil:
-            result.n = copyTree(genericType.n)
-
-        # XXX: doh, we have to treat seq and arrays as special case
-        # because sometimes the `@` magic will be applied to an empty
-        # sequence having the type tySequence(tyEmpty)
-        if changed.kind == tyEmpty and
-           genericType.kind notin {tyArray, tySequence}:
-          if genericType.kind == tyProc and i == 0:
-            # return types of procs are overwritten with nil
-            changed = nil
-          else:
-            # otherwise, `empty` is just erased from the signature
-            result.sons[i..i] = []
-            if result.n != nil: result.n.sons[i..i] = []
-            continue
-        
-        result.sons[head] = changed
-        
-        if result.n != nil:
-          if result.n.kind == nkRecList:
-            for son in result.n.sons:
-              if son.typ == origType:
-                son.typ = changed
-                son.sym = copySym(son.sym, true)
-                son.sym.typ = changed
-          if result.n.kind == nkFormalParams:
-            if i != 0:
-              let origParam = result.n.sons[head].sym
-              var param = copySym(origParam)
-              param.typ = changed
-              param.ast = origParam.ast
-              result.n.sons[head] = newSymNode(param)
-
-      # won't be advanced on empty (void) nodes
-      inc head
-  
-  of tyGenericInvokation:
-    result = newTypeWithSons(c, tyGenericInvokation, genericType.sons)
-    for i in 1 .. <genericType.sons.len:
-      result.sons[i] = fixupProcType(c, result.sons[i], inst)
-    result = instGenericContainer(c, getInfoContext(-1), result)
-  
-  else: discard
-
 proc generateInstance(c: PContext, fn: PSym, pt: TIdTable,
                       info: TLineInfo): PSym =
   # no need to instantiate generic templates/macros:
   if fn.kind in {skTemplate, skMacro}: return fn
-  
+ 
   # generates an instantiated proc
   if c.instCounter > 1000: internalError(fn.ast.info, "nesting too deep")
   inc(c.instCounter)
@@ -281,14 +167,13 @@ proc generateInstance(c: PContext, fn: PSym, pt: TIdTable,
   result.ast = n
   pushOwner(result)
   openScope(c)
-  if n.sons[genericParamsPos].kind == nkEmpty: 
-    internalError(n.info, "generateInstance")
+  internalAssert n.sons[genericParamsPos].kind != nkEmpty
   n.sons[namePos] = newSymNode(result)
   pushInfoContext(info)
   var entry = TInstantiation.new
   entry.sym = result
   instantiateGenericParamList(c, n.sons[genericParamsPos], pt, entry[])
-  result.typ = fixupProcType(c, fn.typ, entry[])
+  result.typ = generateTypeInstance(c, pt, info, fn.typ)
   n.sons[genericParamsPos] = ast.emptyNode
   var oldPrc = genericCacheGet(fn, entry[])
   if oldPrc == nil:
diff --git a/compiler/semmagic.nim b/compiler/semmagic.nim
index 9a2645f7e..a1af94971 100644
--- a/compiler/semmagic.nim
+++ b/compiler/semmagic.nim
@@ -31,7 +31,6 @@ proc semInstantiationInfo(c: PContext, n: PNode): PNode =
   line.intVal = toLinenumber(info)
   result.add(filename)
   result.add(line)
-
  
 proc evalTypeTrait(trait: PNode, operand: PType, context: PSym): PNode =
   let typ = operand.skipTypes({tyTypeDesc})
@@ -40,7 +39,7 @@ proc evalTypeTrait(trait: PNode, operand: PType, context: PSym): PNode =
     result = newStrNode(nkStrLit, typ.typeToString(preferName))
     result.typ = newType(tyString, context)
     result.info = trait.info
-  of "arity":    
+  of "arity":
     result = newIntNode(nkIntLit, typ.n.len-1)
     result.typ = newType(tyInt, context)
     result.info = trait.info
@@ -50,11 +49,11 @@ proc evalTypeTrait(trait: PNode, operand: PType, context: PSym): PNode =
 proc semTypeTraits(c: PContext, n: PNode): PNode =
   checkMinSonsLen(n, 2)
   let t = n.sons[1].typ
-  internalAssert t != nil
-  if t.kind == tyTypeDesc and t.len == 0:
-    result = n
-  elif not containsGenericType(t):
-    result = evalTypeTrait(n[0], t, getCurrOwner())
+  internalAssert t != nil and t.kind == tyTypeDesc
+  if t.sonsLen > 0:
+    # This is either a type known to sem or a typedesc
+    # param to a regular proc (again, known at instantiation)
+    result = evalTypeTrait(n[0], t, GetCurrOwner())
   else:
     # a typedesc variable, pass unmodified to evals
     result = n
@@ -102,7 +101,7 @@ proc semLocals(c: PContext, n: PNode): PNode =
       #if it.owner != c.p.owner: return result
       if it.kind in skLocalVars and
           it.typ.skipTypes({tyGenericInst, tyVar}).kind notin
-              {tyVarargs, tyOpenArray, tyTypeDesc, tyExpr, tyStmt, tyEmpty}:
+            {tyVarargs, tyOpenArray, tyTypeDesc, tyStatic, tyExpr, tyStmt, tyEmpty}:
 
         var field = newSym(skField, it.name, getCurrOwner(), n.info)
         field.typ = it.typ.skipTypes({tyGenericInst, tyVar})
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index 1766c4446..f0007d01e 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -86,7 +86,7 @@ include semdestruct
 
 proc semDestructorCheck(c: PContext, n: PNode, flags: TExprFlags) {.inline.} =
   if efAllowDestructor notin flags and n.kind in nkCallKinds+{nkObjConstr}:
-    if instantiateDestructor(c, n.typ):
+    if instantiateDestructor(c, n.typ) != nil:
       localError(n.info, errGenerated,
         "usage of a type with a destructor in a non destructible context")
   # This still breaks too many things:
@@ -740,16 +740,12 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
       # like: mydata.seq
       rawAddSon(s.typ, newTypeS(tyEmpty, c))
       s.ast = a
-      when oUseLateInstantiation:
-        var body: PType = nil
-        s.typScope = c.currentScope.parent
-      else:
-        inc c.inGenericContext
-        var body = semTypeNode(c, a.sons[2], nil)
-        dec c.inGenericContext
-        if body != nil:
-          body.sym = s
-          body.size = -1 # could not be computed properly
+      inc c.inGenericContext
+      var body = semTypeNode(c, a.sons[2], nil)
+      dec c.inGenericContext
+      if body != nil:
+        body.sym = s
+        body.size = -1 # could not be computed properly
       s.typ.sons[sonsLen(s.typ) - 1] = body
       popOwner()
       closeScope(c)
@@ -1037,12 +1033,16 @@ proc semProcAux(c: PContext, n: PNode, kind: TSymKind,
     pushOwner(s)
   s.options = gOptions
   if sfDestructor in s.flags: doDestructorStuff(c, s, n)
-  if n.sons[bodyPos].kind != nkEmpty: 
+  if n.sons[bodyPos].kind != nkEmpty:
     # for DLL generation it is annoying to check for sfImportc!
-    if sfBorrow in s.flags: 
+    if sfBorrow in s.flags:
       localError(n.sons[bodyPos].info, errImplOfXNotAllowed, s.name.s)
-    if n.sons[genericParamsPos].kind == nkEmpty: 
-      paramsTypeCheck(c, s.typ)
+    let usePseudoGenerics = kind in {skMacro, skTemplate}
+    # Macros and Templates can have generic parameters, but they are
+    # only used for overload resolution (there is no instantiation of
+    # the symbol, so we must process the body now)
+    if n.sons[genericParamsPos].kind == nkEmpty or usePseudoGenerics:
+      if not usePseudoGenerics: paramsTypeCheck(c, s.typ)
       pushProcCon(c, s)
       maybeAddResult(c, s, n)
       if sfImportc notin s.flags:
@@ -1052,13 +1052,13 @@ proc semProcAux(c: PContext, n: PNode, kind: TSymKind,
         # context as it may even be evaluated in 'system.compiles':
         n.sons[bodyPos] = transformBody(c.module, semBody, s)
       popProcCon(c)
-    else: 
+    else:
       if s.typ.sons[0] != nil and kind != skIterator:
         addDecl(c, newSym(skUnknown, getIdent"result", nil, n.info))
       var toBind = initIntSet()
       n.sons[bodyPos] = semGenericStmtScope(c, n.sons[bodyPos], {}, toBind)
       fixupInstantiatedSymbols(c, s)
-    if sfImportc in s.flags: 
+    if sfImportc in s.flags:
       # so we just ignore the body after semantic checking for importc:
       n.sons[bodyPos] = ast.emptyNode
   else:
diff --git a/compiler/semtempl.nim b/compiler/semtempl.nim
index da38f8625..569d92d33 100644
--- a/compiler/semtempl.nim
+++ b/compiler/semtempl.nim
@@ -421,6 +421,7 @@ proc semTemplateDef(c: PContext, n: PNode): PNode =
   else:
     s = semIdentVis(c, skTemplate, n.sons[0], {})
   # check parameter list:
+  s.scope = c.currentScope
   pushOwner(s)
   openScope(c)
   n.sons[namePos] = newSymNode(s, n.sons[namePos].info)
diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index 4fdd84841..64c8f81e2 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -18,7 +18,7 @@ proc newOrPrevType(kind: TTypeKind, prev: PType, c: PContext): PType =
     if result.kind == tyForward: result.kind = kind
 
 proc newConstraint(c: PContext, k: TTypeKind): PType = 
-  result = newTypeS(tyTypeClass, c)
+  result = newTypeS(tyBuiltInTypeClass, c)
   result.addSonSkipIntLit(newTypeS(k, c))
 
 proc semEnum(c: PContext, n: PNode, prev: PType): PType =
@@ -186,6 +186,11 @@ proc semRange(c: PContext, n: PNode, prev: PType): PType =
     localError(n.info, errXExpectsOneTypeParam, "range")
     result = newOrPrevType(tyError, prev, c)
 
+proc nMinusOne(n: PNode): PNode =
+  result = newNode(nkCall, n.info, @[
+    newSymNode(getSysMagic("<", mUnaryLt)),
+    n])
+
 proc semArray(c: PContext, n: PNode, prev: PType): PType = 
   var indx, base: PType
   result = newOrPrevType(tyArray, prev, c)
@@ -194,19 +199,35 @@ proc semArray(c: PContext, n: PNode, prev: PType): PType =
     if isRange(n[1]): indx = semRangeAux(c, n[1], nil)
     else:
       let e = semExprWithType(c, n.sons[1], {efDetermineType})
-      if e.kind in {nkIntLit..nkUInt64Lit}:
+      if e.typ.kind == tyFromExpr:
+        indx = e.typ
+      elif e.kind in {nkIntLit..nkUInt64Lit}:
         indx = makeRangeType(c, 0, e.intVal-1, n.info, e.typ)
-      elif e.kind == nkSym and e.typ.kind == tyExpr:
+      elif e.kind == nkSym and e.typ.kind == tyStatic:
         if e.sym.ast != nil: return semArray(c, e.sym.ast, nil)
         internalAssert c.inGenericContext > 0
         if not isOrdinalType(e.typ.lastSon):
           localError(n[1].info, errOrdinalTypeExpected)
         indx = e.typ
+      elif e.kind in nkCallKinds and hasGenericArguments(e):
+        if not isOrdinalType(e.typ):
+          localError(n[1].info, errOrdinalTypeExpected)
+        # This is an int returning call, depending on an
+        # yet unknown generic param (see tgenericshardcases).
+        # We are going to construct a range type that will be
+        # properly filled-out in semtypinst (see how tyStaticExpr
+        # is handled there).
+        let intType = getSysType(tyInt)
+        indx = newTypeS(tyRange, c)
+        indx.sons = @[intType]
+        indx.n = newNode(nkRange, n.info, @[
+          newIntTypeNode(nkIntLit, 0, intType),
+          makeStaticExpr(c, e.nMinusOne)])
       else:
         indx = e.typ.skipTypes({tyTypeDesc})
     addSonSkipIntLit(result, indx)
     if indx.kind == tyGenericInst: indx = lastSon(indx)
-    if indx.kind notin {tyGenericParam, tyExpr}:
+    if indx.kind notin {tyGenericParam, tyStatic, tyFromExpr}:
       if not isOrdinalType(indx):
         localError(n.sons[1].info, errOrdinalTypeExpected)
       elif enumHasHoles(indx): 
@@ -579,9 +600,9 @@ proc semObjectNode(c: PContext, n: PNode, prev: PType): PType =
     pragma(c, s, n.sons[0], typePragmas)
   if base == nil and tfInheritable notin result.flags:
     incl(result.flags, tfFinal)
-  
+
 proc addParamOrResult(c: PContext, param: PSym, kind: TSymKind) =
-  if kind == skMacro and param.typ.kind != tyTypeDesc:
+  if kind == skMacro and param.typ.kind notin {tyTypeDesc, tyStatic}:
     # within a macro, every param has the type PNimrodNode!
     # and param.typ.kind in {tyTypeDesc, tyExpr, tyStmt}:
     let nn = getSysSym"PNimrodNode"
@@ -593,18 +614,22 @@ proc addParamOrResult(c: PContext, param: PSym, kind: TSymKind) =
 
 let typedescId = getIdent"typedesc"
 
+template shouldHaveMeta(t) =
+  InternalAssert tfHasMeta in t.flags
+  # result.lastSon.flags.incl tfHasMeta
+
 proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
                    paramType: PType, paramName: string,
                    info: TLineInfo, anon = false): PType =
-  if procKind in {skMacro, skTemplate}:
-    # generic param types in macros and templates affect overload
-    # resolution, but don't work as generic params when it comes
-    # to proc instantiation. We don't need to lift such params here.  
-    return
+  if paramType == nil: return # (e.g. proc return type)
 
   proc addImplicitGenericImpl(typeClass: PType, typId: PIdent): PType =
     let finalTypId = if typId != nil: typId
                      else: getIdent(paramName & ":type")
+    if genericParams == nil:
+      # This happens with anonymous proc types appearing in signatures
+      # XXX: we need to lift these earlier
+      return
     # is this a bindOnce type class already present in the param list?
     for i in countup(0, genericParams.len - 1):
       if genericParams.sons[i].sym.name.id == finalTypId.id:
@@ -615,10 +640,11 @@ proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
     var s = newSym(skType, finalTypId, owner, info)
     if typId == nil: s.flags.incl(sfAnon)
     s.linkTo(typeClass)
+    typeClass.flags.incl tfImplicitTypeParam
     s.position = genericParams.len
     genericParams.addSon(newSymNode(s))
     result = typeClass
-
+ 
   # XXX: There are codegen errors if this is turned into a nested proc
   template liftingWalk(typ: PType, anonFlag = false): expr =
     liftParamType(c, procKind, genericParams, typ, paramName, info, anonFlag)
@@ -631,34 +657,38 @@ proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
     addImplicitGenericImpl(e, paramTypId)
 
   case paramType.kind:
-  of tyExpr:
-    if paramType.sonsLen == 0:
-      # proc(a, b: expr)
-      # no constraints, treat like generic param
-      result = addImplicitGeneric(newTypeS(tyGenericParam, c))
-    else:
-      # proc(a: expr{string}, b: expr{nkLambda})
-      # overload on compile time values and AST trees
-      result = addImplicitGeneric(c.newTypeWithSons(tyExpr, paramType.sons))
+  of tyAnything:
+    result = addImplicitGeneric(newTypeS(tyGenericParam, c))
+  
+  of tyStatic:
+    # proc(a: expr{string}, b: expr{nkLambda})
+    # overload on compile time values and AST trees
+    result = addImplicitGeneric(c.newTypeWithSons(tyStatic, paramType.sons))
+    result.flags.incl tfHasStatic
+  
   of tyTypeDesc:
     if tfUnresolved notin paramType.flags:
       # naked typedescs are not bindOnce types
       if paramType.sonsLen == 0 and paramTypId != nil and
          paramTypId.id == typedescId.id: paramTypId = nil
       result = addImplicitGeneric(c.newTypeWithSons(tyTypeDesc, paramType.sons))
+  
   of tyDistinct:
     if paramType.sonsLen == 1:
       # disable the bindOnce behavior for the type class
       result = liftingWalk(paramType.sons[0], true)
-  of tySequence, tySet, tyArray, tyOpenArray:
+  
+  of tySequence, tySet, tyArray, tyOpenArray,
+     tyVar, tyPtr, tyRef, tyProc:
     # XXX: this is a bit strange, but proc(s: seq)
     # produces tySequence(tyGenericParam, null).
     # This also seems to be true when creating aliases
     # like: type myseq = distinct seq.
     # Maybe there is another better place to associate
     # the seq type class with the seq identifier.
-    if paramType.lastSon == nil:
-      let typ = c.newTypeWithSons(tyTypeClass, @[newTypeS(paramType.kind, c)])
+    if paramType.kind == tySequence and paramType.lastSon == nil:
+      let typ = c.newTypeWithSons(tyBuiltInTypeClass,
+                                  @[newTypeS(paramType.kind, c)])
       result = addImplicitGeneric(typ)
     else:
       for i in 0 .. <paramType.sons.len:
@@ -666,29 +696,55 @@ proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
         if lifted != nil:
           paramType.sons[i] = lifted
           result = paramType
+  
   of tyGenericBody:
-    # type Foo[T] = object
-    # proc x(a: Foo, b: Foo) 
-    var typ = newTypeS(tyTypeClass, c)
-    typ.addSonSkipIntLit(paramType)
-    result = addImplicitGeneric(typ)
+    result = newTypeS(tyGenericInvokation, c)
+    result.rawAddSon(paramType)
+    for i in 0 .. paramType.sonsLen - 2:
+      result.rawAddSon newTypeS(tyAnything, c)
+      # result.rawAddSon(copyType(paramType.sons[i], getCurrOwner(), true))
+    result = instGenericContainer(c, paramType.sym.info, result,
+                                  allowMetaTypes = true)
+    result.lastSon.shouldHaveMeta
+    result = newTypeWithSons(c, tyCompositeTypeClass, @[paramType, result])
+    result = addImplicitGeneric(result)
+  
   of tyGenericInst:
     for i in 1 .. (paramType.sons.len - 2):
       var lifted = liftingWalk(paramType.sons[i])
       if lifted != nil:
         paramType.sons[i] = lifted
         result = paramType
+        result.lastSon.shouldHaveMeta
+
+    let liftBody = liftingWalk(paramType.lastSon)
+    if liftBody != nil:
+      result = liftBody
+      result.shouldHaveMeta
+ 
+  of tyGenericInvokation:
+    for i in 1 .. <paramType.sonsLen:
+      let lifted = liftingWalk(paramType.sons[i])
+      if lifted != nil: paramType.sons[i] = lifted
+
+    let expanded = instGenericContainer(c, info, paramType,
+                                        allowMetaTypes = true)
+    result = liftingWalk(expanded)
 
-    if paramType.lastSon.kind == tyTypeClass:
-      result = paramType
-      result.kind = tyParametricTypeClass
-      result = addImplicitGeneric(copyType(result,
-                                           getCurrOwner(), false))
-    elif result != nil:
-      result.kind = tyGenericInvokation
-      result.sons.setLen(result.sons.len - 1)
-  of tyTypeClass:
-    result = addImplicitGeneric(copyType(paramType, getCurrOwner(), false))
+  of tyTypeClass, tyBuiltInTypeClass, tyAnd, tyOr, tyNot:
+    result = addImplicitGeneric(copyType(paramType, getCurrOwner(), true))
+  
+  of tyExpr:
+    if procKind notin {skMacro, skTemplate}:
+      result = addImplicitGeneric(newTypeS(tyAnything, c))
+  
+  of tyGenericParam:
+    if tfGenericTypeParam in paramType.flags and false:
+      if paramType.sonsLen > 0:
+        result = liftingWalk(paramType.lastSon)
+      else:
+        result = addImplicitGeneric(newTypeS(tyAnything, c))
+ 
   else: nil
 
   # result = liftingWalk(paramType)
@@ -745,8 +801,9 @@ proc semProcTypeNode(c: PContext, n, genericParams: PNode,
         if not containsGenericType(typ):
           def = fitNode(c, typ, def)
     if not (hasType or hasDefault):
-      typ = newTypeS(tyExpr, c)
-      
+      let tdef = if kind in {skTemplate, skMacro}: tyExpr else: tyAnything
+      typ = newTypeS(tdef, c)
+
     if skipTypes(typ, {tyGenericInst}).kind == tyEmpty: continue
     for j in countup(0, length-3): 
       var arg = newSymG(skParam, a.sons[j], c)
@@ -804,28 +861,12 @@ proc semBlockType(c: PContext, n: PNode, prev: PType): PType =
   dec(c.p.nestedBlockCounter)
 
 proc semGenericParamInInvokation(c: PContext, n: PNode): PType =
-  # XXX hack 1022 for generics ... would have been nice if the compiler had
-  # been designed with them in mind from start ...
-  when false:
-    if n.kind == nkSym:
-      # for generics we need to lookup the type var again:
-      var s = searchInScopes(c, n.sym.name)
-      if s != nil:
-        if s.kind == skType and s.typ != nil:
-          var t = n.sym.typ
-          echo "came here"
-          return t
-        else:
-          echo "s is crap:"
-          debug(s)
-      else:
-        echo "s is nil!!!!"
   result = semTypeNode(c, n, nil)
 
 proc semGeneric(c: PContext, n: PNode, s: PSym, prev: PType): PType = 
   result = newOrPrevType(tyGenericInvokation, prev, c)
   addSonSkipIntLit(result, s.typ)
-  
+ 
   template addToResult(typ) =
     if typ.isNil:
       internalAssert false
@@ -842,7 +883,7 @@ proc semGeneric(c: PContext, n: PNode, s: PSym, prev: PType): PType =
   else:
     internalAssert s.typ.kind == tyGenericBody
 
-    var m = newCandidate(s, n)
+    var m = newCandidate(c, s, n)
     matches(c, n, copyTree(n), m)
     
     if m.state != csMatch:
@@ -853,7 +894,7 @@ proc semGeneric(c: PContext, n: PNode, s: PSym, prev: PType): PType =
       return newOrPrevType(tyError, prev, c)
 
     var isConcrete = true
-  
+ 
     for i in 1 .. <m.call.len:
       let typ = m.call[i].typ.skipTypes({tyTypeDesc})
       if containsGenericType(typ): isConcrete = false
@@ -864,15 +905,13 @@ proc semGeneric(c: PContext, n: PNode, s: PSym, prev: PType): PType =
         localError(n.info, errCannotInstantiateX, s.name.s)
         result = newOrPrevType(tyError, prev, c)
       else:
-        when oUseLateInstantiation:
-          result = lateInstantiateGeneric(c, result, n.info)
-        else:
-          result = instGenericContainer(c, n, result)
+        result = instGenericContainer(c, n.info, result,
+                                      allowMetaTypes = false)
 
 proc semTypeExpr(c: PContext, n: PNode): PType =
   var n = semExprWithType(c, n, {efDetermineType})
-  if n.kind == nkSym and n.sym.kind == skType:
-    result = n.sym.typ
+  if n.typ.kind == tyTypeDesc:
+    result = n.typ.base
   else:
     localError(n.info, errTypeExpected, n.renderTree)
 
@@ -921,24 +960,27 @@ proc semTypeNode(c: PContext, n: PNode, prev: PType): PType =
         var
           t1 = semTypeNode(c, n.sons[1], nil)
           t2 = semTypeNode(c, n.sons[2], nil)
-        if t1 == nil: 
+        if t1 == nil:
           localError(n.sons[1].info, errTypeExpected)
           result = newOrPrevType(tyError, prev, c)
-        elif t2 == nil: 
+        elif t2 == nil:
           localError(n.sons[2].info, errTypeExpected)
           result = newOrPrevType(tyError, prev, c)
         else:
-          result = newTypeS(tyTypeClass, c)
-          result.addSonSkipIntLit(t1)
-          result.addSonSkipIntLit(t2)
-          result.flags.incl(if op.id == ord(wAnd): tfAll else: tfAny)
-          result.flags.incl(tfHasMeta)
+          result = if op.id == ord(wAnd): makeAndType(c, t1, t2)
+                   else: makeOrType(c, t1, t2)
       elif op.id == ord(wNot):
-        checkSonsLen(n, 3)
-        result = semTypeNode(c, n.sons[1], prev)
-        if result.kind in NilableTypes and n.sons[2].kind == nkNilLit:
-          result = freshType(result, prev)
-          result.flags.incl(tfNotNil)
+        case n.len
+        of 3:
+          result = semTypeNode(c, n.sons[1], prev)
+          if result.kind in NilableTypes and n.sons[2].kind == nkNilLit:
+            result = freshType(result, prev)
+            result.flags.incl(tfNotNil)
+          else:
+            LocalError(n.info, errGenerated, "invalid type")
+        of 2:
+          let negated = semTypeNode(c, n.sons[1], prev)
+          result = makeNotType(c, negated)
         else:
           localError(n.info, errGenerated, "invalid type")
       else:
@@ -968,6 +1010,12 @@ proc semTypeNode(c: PContext, n: PNode, prev: PType): PType =
           result.rawAddSon(semTypeNode(c, n.sons[i], nil))
     else: result = semGeneric(c, n, s, prev)
   of nkIdent, nkDotExpr, nkAccQuoted: 
+    if n.kind == nkDotExpr:
+      let head = qualifiedLookUp(c, n[0], {checkAmbiguity, checkUndeclared})
+      if head.kind in {skType}:
+        var toBind = initIntSet()
+        var preprocessed = semGenericStmt(c, n, {}, toBind)
+        return makeTypeFromExpr(c, preprocessed)
     var s = semTypeIdent(c, n)
     if s.typ == nil: 
       if s.kind != skError: localError(n.info, errTypeExpected)
@@ -1004,6 +1052,11 @@ proc semTypeNode(c: PContext, n: PNode, prev: PType): PType =
   of nkPtrTy: result = semAnyRef(c, n, tyPtr, prev)
   of nkVarTy: result = semVarType(c, n, prev)
   of nkDistinctTy: result = semDistinct(c, n, prev)
+  of nkStaticTy:
+    result = newOrPrevType(tyStatic, prev, c)
+    var base = semTypeNode(c, n.sons[0], nil)
+    result.rawAddSon(base)
+    result.flags.incl tfHasStatic
   of nkProcTy, nkIteratorTy:
     if n.sonsLen == 0:
       result = newConstraint(c, tyProc)
@@ -1088,11 +1141,7 @@ proc processMagicType(c: PContext, m: PSym) =
   else: localError(m.info, errTypeExpected)
   
 proc semGenericConstraints(c: PContext, x: PType): PType =
-  if x.kind in StructuralEquivTypes and (
-      sonsLen(x) == 0 or x.sons[0].kind in {tyGenericParam, tyEmpty}):
-    result = newConstraint(c, x.kind)
-  else:
-    result = newTypeWithSons(c, tyGenericParam, @[x])
+  result = newTypeWithSons(c, tyGenericParam, @[x])
 
 proc semGenericParamList(c: PContext, n: PNode, father: PType = nil): PNode = 
   result = copyNode(n)
@@ -1109,7 +1158,7 @@ proc semGenericParamList(c: PContext, n: PNode, father: PType = nil): PNode =
     
     if constraint.kind != nkEmpty:
       typ = semTypeNode(c, constraint, nil)
-      if typ.kind != tyExpr or typ.len == 0:
+      if typ.kind != tyStatic or typ.len == 0:
         if typ.kind == tyTypeDesc:
           if typ.len == 0:
             typ = newTypeS(tyTypeDesc, c)
@@ -1120,14 +1169,16 @@ proc semGenericParamList(c: PContext, n: PNode, father: PType = nil): PNode =
       def = semConstExpr(c, def)
       if typ == nil:
         if def.typ.kind != tyTypeDesc:
-          typ = newTypeWithSons(c, tyExpr, @[def.typ])
+          typ = newTypeWithSons(c, tyStatic, @[def.typ])
       else:
         if not containsGenericType(def.typ):
           def = fitNode(c, typ, def)
     
     if typ == nil:
       typ = newTypeS(tyGenericParam, c)
-    
+
+    typ.flags.incl tfGenericTypeParam
+
     for j in countup(0, L-3):
       let finalType = if j == 0: typ
                       else: copyType(typ, typ.owner, false)
@@ -1136,7 +1187,7 @@ proc semGenericParamList(c: PContext, n: PNode, father: PType = nil): PNode =
                       # of the parameter will be stored in the
                       # attached symbol.
       var s = case finalType.kind
-        of tyExpr:
+        of tyStatic:
           newSymG(skGenericParam, a.sons[j], c).linkTo(finalType)
         else:
           newSymG(skType, a.sons[j], c).linkTo(finalType)
diff --git a/compiler/semtypinst.nim b/compiler/semtypinst.nim
index 2e2d54b5b..b08119d4a 100644
--- a/compiler/semtypinst.nim
+++ b/compiler/semtypinst.nim
@@ -11,20 +11,23 @@
 
 import ast, astalgo, msgs, types, magicsys, semdata, renderer
 
+const
+  tfInstClearedFlags = {tfHasMeta}
+
 proc checkPartialConstructedType(info: TLineInfo, t: PType) =
   if tfAcyclic in t.flags and skipTypes(t, abstractInst).kind != tyObject:
     localError(info, errInvalidPragmaX, "acyclic")
   elif t.kind == tyVar and t.sons[0].kind == tyVar:
     localError(info, errVarVarTypeNotAllowed)
 
-proc checkConstructedType*(info: TLineInfo, typ: PType) = 
+proc checkConstructedType*(info: TLineInfo, typ: PType) =
   var t = typ.skipTypes({tyDistinct})
-  if t.kind in {tyTypeClass}: nil
+  if t.kind in tyTypeClasses: nil
   elif tfAcyclic in t.flags and skipTypes(t, abstractInst).kind != tyObject: 
     localError(info, errInvalidPragmaX, "acyclic")
   elif t.kind == tyVar and t.sons[0].kind == tyVar: 
     localError(info, errVarVarTypeNotAllowed)
-  elif computeSize(t) < 0:
+  elif computeSize(t) == szIllegalRecursion:
     localError(info, errIllegalRecursionInTypeX, typeToString(t))
   when false:
     if t.kind == tyObject and t.sons[0] != nil:
@@ -50,9 +53,10 @@ proc searchInstTypes*(key: PType): PType =
     block matchType:
       for j in 1 .. high(key.sons):
         # XXX sameType is not really correct for nested generics?
-        if not sameType(inst.sons[j], key.sons[j]):
+        if not compareTypes(inst.sons[j], key.sons[j],
+                            flags = {ExactGenericParams}):
           break matchType
-      
+       
       return inst
 
 proc cacheTypeInst*(inst: PType) =
@@ -66,25 +70,84 @@ type
     c*: PContext
     typeMap*: TIdTable        # map PType to PType
     symMap*: TIdTable         # map PSym to PSym
+    localCache*: TIdTable     # local cache for remembering alraedy replaced
+                              # types during instantiation of meta types
+                              # (they are not stored in the global cache)
     info*: TLineInfo
+    allowMetaTypes*: bool     # allow types such as seq[Number]
+                              # i.e. the result contains unresolved generics
 
-proc replaceTypeVarsT*(cl: var TReplTypeVars, t: PType): PType
+proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType): PType
 proc replaceTypeVarsS(cl: var TReplTypeVars, s: PSym): PSym
 proc replaceTypeVarsN(cl: var TReplTypeVars, n: PNode): PNode
 
+template checkMetaInvariants(cl: TReplTypeVars, t: PType) =
+  when false:
+    if t != nil and tfHasMeta in t.flags and
+       cl.allowMetaTypes == false:
+      echo "UNEXPECTED META ", t.id, " ", instantiationInfo(-1)
+      debug t
+      writeStackTrace()
+      quit 1
+
+proc replaceTypeVarsT*(cl: var TReplTypeVars, t: PType): PType =
+  result = replaceTypeVarsTAux(cl, t)
+  checkMetaInvariants(cl, result)
+
 proc prepareNode(cl: var TReplTypeVars, n: PNode): PNode =
   result = copyNode(n)
   result.typ = replaceTypeVarsT(cl, n.typ)
   if result.kind == nkSym: result.sym = replaceTypeVarsS(cl, n.sym)
-  for i in 0 .. safeLen(n)-1: 
-    # XXX HACK: ``f(a, b)``, avoid to instantiate `f` 
-    if i == 0: result.add(n[i])
+  let isCall = result.kind in nkCallKinds
+  for i in 0 .. <n.safeLen:
+    # XXX HACK: ``f(a, b)``, avoid to instantiate `f`
+    if isCall and i == 0: result.add(n[i])
     else: result.add(prepareNode(cl, n[i]))
 
+proc isTypeParam(n: PNode): bool =
+  # XXX: generic params should use skGenericParam instead of skType
+  return n.kind == nkSym and
+         (n.sym.kind == skGenericParam or
+           (n.sym.kind == skType and sfFromGeneric in n.sym.flags))
+
+proc hasGenericArguments*(n: PNode): bool =
+  if n.kind == nkSym:
+    return n.sym.kind == skGenericParam or
+           (n.sym.kind == skType and
+            n.sym.typ.flags * {tfGenericTypeParam, tfImplicitTypeParam} != {})
+  else:
+    for s in n.sons:
+      if hasGenericArguments(s): return true
+    return false
+
+proc reResolveCallsWithTypedescParams(cl: var TReplTypeVars, n: PNode): PNode =
+  # This is needed fo tgenericshardcases
+  # It's possible that a generic param will be used in a proc call to a
+  # typedesc accepting proc. After generic param substitution, such procs
+  # should be optionally instantiated with the correct type. In order to
+  # perform this instantiation, we need to re-run the generateInstance path
+  # in the compiler, but it's quite complicated to do so at the moment so we
+  # resort to a mild hack; the head symbol of the call is temporary reset and
+  # overload resolution is executed again (which may trigger generateInstance).
+  if n.kind in nkCallKinds and sfFromGeneric in n[0].sym.flags:
+    var needsFixing = false
+    for i in 1 .. <n.safeLen:
+      if isTypeParam(n[i]): needsFixing = true
+    if needsFixing:
+      n.sons[0] = newSymNode(n.sons[0].sym.owner)
+      return cl.c.semOverloadedCall(cl.c, n, n, {skProc})
+  
+  for i in 0 .. <n.safeLen:
+    n.sons[i] = reResolveCallsWithTypedescParams(cl, n[i])
+
+  return n
+
 proc replaceTypeVarsN(cl: var TReplTypeVars, n: PNode): PNode =
   if n == nil: return
   result = copyNode(n)
-  result.typ = replaceTypeVarsT(cl, n.typ)
+  if n.typ != nil:
+    result.typ = replaceTypeVarsT(cl, n.typ)
+    checkMetaInvariants(cl, result.typ)
   case n.kind
   of nkNone..pred(nkSym), succ(nkSym)..nkNilLit:
     discard
@@ -111,6 +174,10 @@ proc replaceTypeVarsN(cl: var TReplTypeVars, n: PNode): PNode =
       result = replaceTypeVarsN(cl, branch)
     else:
       result = newNodeI(nkRecList, n.info)
+  of nkStaticExpr:
+    var n = prepareNode(cl, n)
+    n = reResolveCallsWithTypedescParams(cl, n)
+    result = cl.c.semExpr(cl.c, n)
   else:
     var length = sonsLen(n)
     if length > 0:
@@ -132,11 +199,18 @@ proc replaceTypeVarsS(cl: var TReplTypeVars, s: PSym): PSym =
 proc lookupTypeVar(cl: TReplTypeVars, t: PType): PType = 
   result = PType(idTableGet(cl.typeMap, t))
   if result == nil:
+    if cl.allowMetaTypes or tfRetType in t.flags: return
     localError(t.sym.info, errCannotInstantiateX, typeToString(t))
     result = errorType(cl.c)
-  elif result.kind == tyGenericParam: 
+  elif result.kind == tyGenericParam and not cl.allowMetaTypes:
     internalError(cl.info, "substitution with generic parameter")
-  
+
+proc instCopyType(cl: var TReplTypeVars, t: PType): PType =
+  # XXX: relying on allowMetaTypes is a kludge
+  result = copyType(t, t.owner, cl.allowMetaTypes)
+  result.flags.incl tfFromGeneric
+  result.flags.excl tfInstClearedFlags
+
 proc handleGenericInvokation(cl: var TReplTypeVars, t: PType): PType = 
   # tyGenericInvokation[A, tyGenericInvokation[A, B]]
   # is difficult to handle: 
@@ -144,29 +218,37 @@ proc handleGenericInvokation(cl: var TReplTypeVars, t: PType): PType =
   if body.kind != tyGenericBody: internalError(cl.info, "no generic body")
   var header: PType = nil
   # search for some instantiation here:
-  result = searchInstTypes(t)
+  if cl.allowMetaTypes:
+    result = PType(idTableGet(cl.localCache, t))
+  else:
+    result = searchInstTypes(t)
   if result != nil: return
   for i in countup(1, sonsLen(t) - 1):
     var x = t.sons[i]
     if x.kind == tyGenericParam:
       x = lookupTypeVar(cl, x)
-      if header == nil: header = copyType(t, t.owner, false)
-      header.sons[i] = x
-      propagateToOwner(header, x)
-      #idTablePut(cl.typeMap, body.sons[i-1], x)  
-
+      if x != nil:
+        if header == nil: header = instCopyType(cl, t)
+        header.sons[i] = x
+        propagateToOwner(header, x)
+  
   if header != nil:
     # search again after first pass:
     result = searchInstTypes(header)
     if result != nil: return
   else:
-    header = copyType(t, t.owner, false)
+    header = instCopyType(cl, t)
+  
+  result = newType(tyGenericInst, t.sons[0].owner)
+  # be careful not to propagate unnecessary flags here (don't use rawAddSon)
+  result.sons = @[header.sons[0]]
   # ugh need another pass for deeply recursive generic types (e.g. PActor)
   # we need to add the candidate here, before it's fully instantiated for
   # recursive instantions:
-  result = newType(tyGenericInst, t.sons[0].owner)
-  result.rawAddSon(header.sons[0])
-  cacheTypeInst(result)
+  if not cl.allowMetaTypes:
+    cacheTypeInst(result)
+  else:
+    idTablePut(cl.localCache, t, result)
 
   for i in countup(1, sonsLen(t) - 1):
     var x = replaceTypeVarsT(cl, t.sons[i])
@@ -175,70 +257,165 @@ proc handleGenericInvokation(cl: var TReplTypeVars, t: PType): PType =
     propagateToOwner(header, x)
     idTablePut(cl.typeMap, body.sons[i-1], x)
   
-  for i in countup(1, sonsLen(t) - 1): 
+  for i in countup(1, sonsLen(t) - 1):
     # if one of the params is not concrete, we cannot do anything
     # but we already raised an error!
     rawAddSon(result, header.sons[i])
-  
+
   var newbody = replaceTypeVarsT(cl, lastSon(body))
-  newbody.flags = newbody.flags + t.flags + body.flags
+  newbody.flags = newbody.flags + (t.flags + body.flags - tfInstClearedFlags)
   result.flags = result.flags + newbody.flags
   newbody.callConv = body.callConv
-  newbody.n = replaceTypeVarsN(cl, lastSon(body).n)
   # This type may be a generic alias and we want to resolve it here.
   # One step is enough, because the recursive nature of
   # handleGenericInvokation will handle the alias-to-alias-to-alias case
   if newbody.isGenericAlias: newbody = newbody.skipGenericAlias
   rawAddSon(result, newbody)
   checkPartialConstructedType(cl.info, newbody)
+
+proc eraseVoidParams(t: PType) =
+  if t.sons[0] != nil and t.sons[0].kind == tyEmpty:
+    t.sons[0] = nil
   
-proc replaceTypeVarsT*(cl: var TReplTypeVars, t: PType): PType = 
+  for i in 1 .. <t.sonsLen:
+    # don't touch any memory unless necessary
+    if t.sons[i].kind == tyEmpty:
+      var pos = i
+      for j in i+1 .. <t.sonsLen:
+        if t.sons[j].kind != tyEmpty:
+          t.sons[pos] = t.sons[j]
+          t.n.sons[pos] = t.n.sons[j]
+          inc pos
+      setLen t.sons, pos
+      setLen t.n.sons, pos
+      return
+
+proc skipIntLiteralParams(t: PType) =
+  for i in 0 .. <t.sonsLen:
+    let p = t.sons[i]
+    if p == nil: continue
+    let skipped = p.skipIntLit
+    if skipped != p:
+      t.sons[i] = skipped
+      if i > 0: t.n.sons[i].sym.typ = skipped
+
+proc propagateFieldFlags(t: PType, n: PNode) =
+  # This is meant for objects and tuples
+  # The type must be fully instantiated!
+  internalAssert n.kind != nkRecWhen
+  case n.kind
+  of nkSym:
+    propagateToOwner(t, n.sym.typ)
+  of nkRecList, nkRecCase, nkOfBranch, nkElse:
+    if n.sons != nil:
+      for son in n.sons:
+        propagateFieldFlags(t, son)
+  else: discard
+
+proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType): PType =
   result = t
-  if t == nil: return 
+  if t == nil: return
+
+  if t.kind in {tyStatic, tyGenericParam} + tyTypeClasses:
+    let lookup = PType(idTableGet(cl.typeMap, t))
+    if lookup != nil: return lookup
+  
   case t.kind
-  of tyTypeClass: discard
-  of tyGenericParam:
-    result = lookupTypeVar(cl, t)
-    if result.kind == tyGenericInvokation:
-      result = handleGenericInvokation(cl, result)
-  of tyExpr:
-    if t.sym != nil and t.sym.kind == skGenericParam:
-      result = lookupTypeVar(cl, t)
-  of tyGenericInvokation: 
+  of tyGenericInvokation:
     result = handleGenericInvokation(cl, t)
+
   of tyGenericBody:
-    internalError(cl.info, "ReplaceTypeVarsT: tyGenericBody")
+    internalError(cl.info, "ReplaceTypeVarsT: tyGenericBody" )
     result = replaceTypeVarsT(cl, lastSon(t))
+
+  of tyFromExpr:
+    var n = prepareNode(cl, t.n)
+    n = cl.c.semConstExpr(cl.c, n)
+    if n.typ.kind == tyTypeDesc:
+      # XXX: sometimes, chained typedescs enter here.
+      # It may be worth investigating why this is happening,
+      # because it may cause other bugs elsewhere.
+      result = n.typ.skipTypes({tyTypeDesc})
+      # result = n.typ.base
+    else:
+      if n.typ.kind != tyStatic:
+        # XXX: In the future, semConstExpr should
+        # return tyStatic values to let anyone make
+        # use of this knowledge. The patching here
+        # won't be necessary then.
+        result = newTypeS(tyStatic, cl.c)
+        result.sons = @[n.typ]
+        result.n = n
+      else:
+        result = n.typ
+
   of tyInt:
     result = skipIntLit(t)
     # XXX now there are also float literals
+  
+  of tyTypeDesc:
+    let lookup = PType(idTableGet(cl.typeMap, t)) # lookupTypeVar(cl, t)
+    if lookup != nil:
+      result = lookup
+      if tfUnresolved in t.flags: result = result.base
+    elif t.sonsLen > 0:
+      result = makeTypeDesc(cl.c, replaceTypeVarsT(cl, t.sons[0]))
+  
+  of tyGenericInst:
+    result = instCopyType(cl, t)
+    for i in 1 .. <result.sonsLen:
+      result.sons[i] = ReplaceTypeVarsT(cl, result.sons[i])
+    propagateToOwner(result, result.lastSon)
+  
   else:
-    if t.kind == tyArray:
-      let idxt = t.sons[0]
-      if idxt.kind == tyExpr and 
-         idxt.sym != nil and idxt.sym.kind == skGenericParam:
-        let value = lookupTypeVar(cl, idxt).n
-        t.sons[0] = makeRangeType(cl.c, 0, value.intVal - 1, value.info)
     if containsGenericType(t):
-      result = copyType(t, t.owner, false)
-      incl(result.flags, tfFromGeneric)
+      result = instCopyType(cl, t)
       result.size = -1 # needs to be recomputed
+      
       for i in countup(0, sonsLen(result) - 1):
-        result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
+        if result.sons[i] != nil:
+          result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
+          propagateToOwner(result, result.sons[i])
+
       result.n = replaceTypeVarsN(cl, result.n)
-      if result.kind in GenericTypes:
-        localError(cl.info, errCannotInstantiateX, typeToString(t, preferName))
-      if result.kind == tyProc and result.sons[0] != nil:
-        if result.sons[0].kind == tyEmpty:
-          result.sons[0] = nil
-  
-proc generateTypeInstance*(p: PContext, pt: TIdTable, arg: PNode, 
-                           t: PType): PType = 
+      
+      # XXX: This is not really needed?
+      # if result.kind in GenericTypes:
+      #   localError(cl.info, errCannotInstantiateX, typeToString(t, preferName))
+
+      case result.kind
+      of tyArray:
+        let idx = result.sons[0]
+        if idx.kind == tyStatic:
+          if idx.n == nil:
+            let lookup = lookupTypeVar(cl, idx)
+            internalAssert lookup != nil
+            idx.n = lookup.n
+
+          result.sons[0] = makeRangeType(cl.c, 0, idx.n.intVal - 1, idx.n.info)
+       
+      of tyObject, tyTuple:
+        propagateFieldFlags(result, result.n)
+      
+      of tyProc:
+        eraseVoidParams(result)
+        skipIntLiteralParams(result)
+      
+      else: discard
+
+proc generateTypeInstance*(p: PContext, pt: TIdTable, info: TLineInfo,
+                           t: PType): PType =
   var cl: TReplTypeVars
   initIdTable(cl.symMap)
   copyIdTable(cl.typeMap, pt)
-  cl.info = arg.info
+  initIdTable(cl.localCache)
+  cl.info = info
   cl.c = p
-  pushInfoContext(arg.info)
+  pushInfoContext(info)
   result = replaceTypeVarsT(cl, t)
   popInfoContext()
+
+template generateTypeInstance*(p: PContext, pt: TIdTable, arg: PNode,
+                               t: PType): expr =
+  generateTypeInstance(p, pt, arg.info, t)
+
diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index 201f61dec..7066c5afd 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -21,7 +21,8 @@ type
   TCandidateState* = enum 
     csEmpty, csMatch, csNoMatch
 
-  TCandidate* {.final.} = object 
+  TCandidate* {.final.} = object
+    c*: PContext
     exactMatches*: int       # also misused to prefer iters over procs
     genericMatches: int      # also misused to prefer constraints
     subtypeMatches: int
@@ -30,7 +31,8 @@ type
     state*: TCandidateState
     callee*: PType           # may not be nil!
     calleeSym*: PSym         # may be nil
-    calleeScope: int         # may be -1 for unknown scope
+    calleeScope*: int        # scope depth:
+                             # is this a top-level symbol or a nested proc?
     call*: PNode             # modified call
     bindings*: TIdTable      # maps types to types
     baseTypeMatch: bool      # needed for conversions from T to openarray[T]
@@ -58,7 +60,9 @@ const
     
 proc markUsed*(n: PNode, s: PSym)
 
-proc initCandidateAux(c: var TCandidate, callee: PType) {.inline.} = 
+proc initCandidateAux(ctx: PContext,
+                      c: var TCandidate, callee: PType) {.inline.} =
+  c.c = ctx
   c.exactMatches = 0
   c.subtypeMatches = 0
   c.convMatches = 0
@@ -71,32 +75,44 @@ proc initCandidateAux(c: var TCandidate, callee: PType) {.inline.} =
   c.genericConverter = false
   c.inheritancePenalty = 0
 
-proc initCandidate*(c: var TCandidate, callee: PType) = 
-  initCandidateAux(c, callee)
+proc initCandidate*(ctx: PContext, c: var TCandidate, callee: PType) =
+  initCandidateAux(ctx, c, callee)
   c.calleeSym = nil
   initIdTable(c.bindings)
 
 proc put(t: var TIdTable, key, val: PType) {.inline.} =
   idTablePut(t, key, val)
 
-proc initCandidate*(c: var TCandidate, callee: PSym, binding: PNode, 
-                    calleeScope = -1) =
-  initCandidateAux(c, callee.typ)
+proc initCandidate*(ctx: PContext, c: var TCandidate, callee: PSym,
+                    binding: PNode, calleeScope = -1) =
+  initCandidateAux(ctx, c, callee.typ)
   c.calleeSym = callee
-  c.calleeScope = calleeScope
+  if callee.kind in skProcKinds and calleeScope == -1:
+    if callee.originatingModule == ctx.module:
+      let rootSym = if sfFromGeneric notin callee.flags: callee
+                    else: callee.owner
+      c.calleeScope = rootSym.scope.depthLevel
+    else:
+      c.calleeScope = 1
+  else:
+    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):
       var formalTypeParam = typeParams.sons[i-1].typ
-      #debug(formalTypeParam)
-      put(c.bindings, formalTypeParam, binding[i].typ)
+      var bound = binding[i].typ
+      if formalTypeParam.kind != tyTypeDesc:
+        bound = bound.skipTypes({tyTypeDesc})
+      put(c.bindings, formalTypeParam, bound)
 
-proc newCandidate*(callee: PSym, binding: PNode, calleeScope = -1): TCandidate =
-  initCandidate(result, callee, binding, calleeScope)
+proc newCandidate*(ctx: PContext, callee: PSym,
+                   binding: PNode, calleeScope = -1): TCandidate =
+  initCandidate(ctx, result, callee, binding, calleeScope)
 
 proc copyCandidate(a: var TCandidate, b: TCandidate) = 
+  a.c = b.c
   a.exactMatches = b.exactMatches
   a.subtypeMatches = b.subtypeMatches
   a.convMatches = b.convMatches
@@ -124,7 +140,7 @@ proc sumGeneric(t: PType): int =
       result = ord(t.kind == tyGenericInvokation)
       for i in 0 .. <t.len: result += t.sons[i].sumGeneric
       break
-    of tyGenericParam, tyExpr, tyStmt, tyTypeDesc, tyTypeClass: break
+    of tyGenericParam, tyExpr, tyStatic, tyStmt, tyTypeDesc, tyTypeClass: break
     else: return 0
 
 proc complexDisambiguation(a, b: PType): int =
@@ -159,9 +175,8 @@ proc cmpCandidates*(a, b: TCandidate): int =
   if result != 0: return
   result = a.convMatches - b.convMatches
   if result != 0: return
-  if (a.calleeScope != -1) and (b.calleeScope != -1):
-    result = a.calleeScope - b.calleeScope
-    if result != 0: return
+  result = a.calleeScope - b.calleeScope
+  if result != 0: return
   # the other way round because of other semantics:
   result = b.inheritancePenalty - a.inheritancePenalty
   if result != 0: return
@@ -203,7 +218,7 @@ 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, doBind = true): TTypeRelation
+proc typeRel*(c: var TCandidate, f, aOrig: PType, doBind = true): TTypeRelation
 proc concreteType(c: TCandidate, t: PType): PType = 
   case t.kind
   of tyArrayConstr: 
@@ -296,24 +311,27 @@ proc minRel(a, b: TTypeRelation): TTypeRelation =
   if a <= b: result = a
   else: result = b
   
-proc tupleRel(c: var TCandidate, f, a: PType): TTypeRelation =
+proc recordRel(c: var TCandidate, f, a: PType): TTypeRelation =
   result = isNone
-  if sameType(f, a):
-    result = isEqual
+  if sameType(f, a): result = isEqual
   elif sonsLen(a) == sonsLen(f):
     result = isEqual
-    for i in countup(0, sonsLen(f) - 1):
+    let firstField = if f.kind == tyTuple: 0
+                     else: 1 
+    for i in countup(firstField, sonsLen(f) - 1):
       var m = typeRel(c, f.sons[i], a.sons[i])
       if m < isSubtype: return isNone
       result = minRel(result, m)
     if f.n != nil and a.n != nil:
       for i in countup(0, sonsLen(f.n) - 1):
         # check field names:
-        if f.n.sons[i].kind != nkSym: internalError(f.n.info, "tupleRel")
-        elif a.n.sons[i].kind != nkSym: internalError(a.n.info, "tupleRel")
+        if f.n.sons[i].kind != nkSym: internalError(f.n.info, "recordRel")
+        elif a.n.sons[i].kind != nkSym: internalError(a.n.info, "recordRel")
         else:
           var x = f.n.sons[i].sym
           var y = a.n.sons[i].sym
+          if f.kind == tyObject and typeRel(c, x.typ, y.typ) < isSubtype:
+            return isNone
           if x.name.id != y.name.id: return isNone
 
 proc allowsNil(f: PType): TTypeRelation {.inline.} =
@@ -365,10 +383,6 @@ proc procTypeRel(c: var TCandidate, f, a: PType): TTypeRelation =
   of tyNil: result = f.allowsNil
   else: nil
 
-proc matchTypeClass(c: var TCandidate, f, a: PType): TTypeRelation =
-  result = if matchTypeClass(c.bindings, f, a): isGeneric
-           else: isNone
-
 proc typeRangeRel(f, a: PType): TTypeRelation {.noinline.} =
   let
     a0 = firstOrd(a)
@@ -385,7 +399,7 @@ proc typeRangeRel(f, a: PType): TTypeRelation {.noinline.} =
   else:
     result = isNone
 
-proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
+proc typeRel(c: var TCandidate, f, aOrig: PType, doBind = true): TTypeRelation =
   # typeRel can be used to establish various relationships between types:
   #
   # 1) When used with concrete types, it will check for type equivalence
@@ -401,22 +415,31 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
   # order to give preferrence to the most specific one:
   #
   # seq[seq[any]] is a strict subset of seq[any] and hence more specific.
-  
+
   result = isNone
   assert(f != nil)
-  assert(a != nil)
+  assert(aOrig != nil)
+
+  # var and static arguments match regular modifier-free types
+  let a = aOrig.skipTypes({tyStatic, tyVar})
+  
   if a.kind == tyGenericInst and
       skipTypes(f, {tyVar}).kind notin {
         tyGenericBody, tyGenericInvokation,
-        tyGenericParam, tyTypeClass}:
+        tyGenericInst, tyGenericParam} + tyTypeClasses:
     return typeRel(c, f, lastSon(a))
-  if a.kind == tyVar and f.kind != tyVar:
-    return typeRel(c, f, a.sons[0])
-  
+
   template bindingRet(res) =
-    when res == isGeneric: put(c.bindings, f, a)
+    when res == isGeneric:
+      let bound = aOrig.skipTypes({tyRange}).skipIntLit
+      put(c.bindings, f, bound)
     return res
- 
+
+  template considerPreviousT(body: stmt) {.immediate.} =
+    var prev = PType(idTableGet(c.bindings, f))
+    if prev == nil: body
+    else: return typeRel(c, prev, a)
+
   case a.kind
   of tyOr:
     # seq[int|string] vs seq[number]
@@ -457,10 +480,10 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
   else: nil
 
   case f.kind
-  of tyEnum: 
+  of tyEnum:
     if a.kind == f.kind and sameEnumTypes(f, a): result = isEqual
     elif sameEnumTypes(f, skipTypes(a, {tyRange})): result = isSubtype
-  of tyBool, tyChar: 
+  of tyBool, tyChar:
     if a.kind == f.kind: result = isEqual
     elif skipTypes(a, {tyRange}).kind == f.kind: result = isSubtype
   of tyRange:
@@ -488,9 +511,9 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
   of tyFloat32:  result = handleFloatRange(f, a)
   of tyFloat64:  result = handleFloatRange(f, a)
   of tyFloat128: result = handleFloatRange(f, a)
-  of tyVar: 
-    if a.kind == f.kind: result = typeRel(c, base(f), base(a))
-    else: result = typeRel(c, base(f), a)
+  of tyVar:
+    if aOrig.kind == tyVar: result = typeRel(c, f.base, aOrig.base)
+    else: result = typeRel(c, f.base, aOrig)
   of tyArray, tyArrayConstr:
     # tyArrayConstr cannot happen really, but
     # we wanna be safe here
@@ -544,7 +567,6 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
   of tyOrdinal:
     if isOrdinalType(a):
       var x = if a.kind == tyOrdinal: a.sons[0] else: a
-     
       if f.sonsLen == 0:
         result = isGeneric
       else:
@@ -556,10 +578,12 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
   of tyNil:
     if a.kind == f.kind: result = isEqual
   of tyTuple: 
-    if a.kind == tyTuple: result = tupleRel(c, f, a)
+    if a.kind == tyTuple: result = recordRel(c, f, a)
   of tyObject:
     if a.kind == tyObject:
-      if sameObjectTypes(f, a): result = isEqual
+      if sameObjectTypes(f, a):
+        result = isEqual
+        # elif tfHasMeta in f.flags: result = recordRel(c, f, a)
       else:
         var depth = isObjectSubtype(a, f)
         if depth > 0:
@@ -641,11 +665,26 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
     if a.kind == tyEmpty: result = isEqual
 
   of tyGenericInst:
-    result = typeRel(c, lastSon(f), a)
+    let roota = a.skipGenericAlias
+    let rootf = f.skipGenericAlias
+    if a.kind == tyGenericInst and roota.base == rootf.base :
+      for i in 1 .. rootf.sonsLen-2:
+        let ff = rootf.sons[i]
+        let aa = roota.sons[i]
+        result = typeRel(c, ff, aa)
+        if result == isNone: return        
+        if ff.kind == tyRange and result != isEqual: return isNone
+
+      result = isGeneric
+    else:
+      result = typeRel(c, lastSon(f), a)
 
   of tyGenericBody:
-    let ff = lastSon(f)
-    if ff != nil: result = typeRel(c, ff, a)
+    considerPreviousT:
+      if a.kind == tyGenericInst and a.sons[0] == f:
+        bindingRet isGeneric
+      let ff = lastSon(f)
+      if ff != nil: result = typeRel(c, ff, a)
 
   of tyGenericInvokation:
     var x = a.skipGenericAlias
@@ -672,36 +711,54 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
           put(c.bindings, f.sons[i], x)
   
   of tyAnd:
-    for branch in f.sons:
-      if typeRel(c, branch, a) == isNone:
-        return isNone
+    considerPreviousT:
+      for branch in f.sons:
+        if typeRel(c, branch, aOrig) == isNone:
+          return isNone
 
-    bindingRet isGeneric
+      bindingRet isGeneric
 
   of tyOr:
-    for branch in f.sons:
-      if typeRel(c, branch, a) != isNone:
-        bindingRet isGeneric
-
-    return isNone
+    considerPreviousT:
+      for branch in f.sons:
+        if typeRel(c, branch, aOrig) != isNone:
+          bindingRet isGeneric
+       
+      return isNone
 
   of tyNot:
-    for branch in f.sons:
-      if typeRel(c, branch, a) != isNone:
-        return isNone
-    
-    bindingRet isGeneric
+    considerPreviousT:
+      for branch in f.sons:
+        if typeRel(c, branch, aOrig) != isNone:
+          return isNone
+      
+      bindingRet isGeneric
 
   of tyAnything:
-    var prev = PType(idTableGet(c.bindings, f))
-    if prev == nil:
+    considerPreviousT:
       var concrete = concreteType(c, a)
       if concrete != nil and doBind:
         put(c.bindings, f, concrete)
       return isGeneric
-    else:
-      return typeRel(c, prev, a)
-    
+
+  of tyBuiltInTypeClass:
+    considerPreviousT:
+      let targetKind = f.sons[0].kind
+      if targetKind == a.skipTypes({tyRange, tyGenericInst}).kind or
+         (targetKind in {tyProc, tyPointer} and a.kind == tyNil):
+        put(c.bindings, f, a)
+        return isGeneric
+      else:
+        return isNone
+
+  of tyCompositeTypeClass:
+    considerPreviousT:
+      if typeRel(c, f.sons[1], a) != isNone:
+        put(c.bindings, f, a)
+        return isGeneric
+      else:
+        return isNone
+
   of tyGenericParam, tyTypeClass:
     var x = PType(idTableGet(c.bindings, f))
     if x == nil:
@@ -722,11 +779,11 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
         else:
           result = isNone
       else:
-        if a.kind == tyTypeClass:
-          result = isGeneric
+        if f.sonsLen > 0:
+          result = typeRel(c, f.lastSon, a)
         else:
-          result = matchTypeClass(c, f, a)
-        
+          result = isGeneric
+
       if result == isGeneric:
         var concrete = concreteType(c, a)
         if concrete == nil:
@@ -739,6 +796,14 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
       result = isGeneric
     else:
       result = typeRel(c, x, a) # check if it fits
+  
+  of tyStatic:
+    if aOrig.kind == tyStatic:
+      result = typeRel(c, f.lastSon, a)
+      if result != isNone: put(c.bindings, f, aOrig)
+    else:
+      result = isNone
+
   of tyTypeDesc:
     var prev = PType(idTableGet(c.bindings, f))
     if prev == nil:
@@ -746,8 +811,8 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
         if f.sonsLen == 0:
           result = isGeneric
         else:
-          result = matchTypeClass(c, f, a.sons[0])
-        if result == isGeneric:
+          result = typeRel(c, f.sons[0], a.sons[0])
+        if result != isNone:
           put(c.bindings, f, a)
       else:
         result = isNone
@@ -756,16 +821,19 @@ proc typeRel(c: var TCandidate, f, a: PType, doBind = true): TTypeRelation =
       let toMatch = if tfUnresolved in f.flags: a
                     else: a.sons[0]
       result = typeRel(c, prev.sons[0], toMatch)
+  
   of tyExpr, tyStmt:
     result = isGeneric
+  
   of tyProxy:
     result = isEqual
+  
   else: internalError("typeRel: " & $f.kind)
   
-proc cmpTypes*(f, a: PType): TTypeRelation = 
-  var c: TCandidate
-  initCandidate(c, f)
-  result = typeRel(c, f, a)
+proc cmpTypes*(c: PContext, f, a: PType): TTypeRelation = 
+  var m: TCandidate
+  initCandidate(c, m, f)
+  result = typeRel(m, f, a)
 
 proc getInstantiatedType(c: PContext, arg: PNode, m: TCandidate, 
                          f: PType): PType = 
@@ -887,47 +955,34 @@ proc matchUserTypeClass*(c: PContext, m: var TCandidate,
   result = arg
   put(m.bindings, f, a)
 
-proc paramTypesMatchAux(c: PContext, m: var TCandidate, f, argType: PType,
+proc paramTypesMatchAux(m: var TCandidate, f, argType: PType,
                         argSemantized, argOrig: PNode): PNode =
   var
-    r: TTypeRelation
+    fMaybeStatic = f.skipTypes({tyDistinct})
     arg = argSemantized
-
-  let
-    a = if c.inTypeClass > 0: argType.skipTypes({tyTypeDesc})
+    argType = argType
+    c = m.c
+
+  if tfHasStatic in fMaybeStatic.flags:
+    # XXX: When implicit statics are the default
+    # this will be done earlier - we just have to
+    # make sure that static types enter here
+    var evaluated = c.semTryConstExpr(c, arg)
+    if evaluated != nil:
+      arg.typ = newTypeS(tyStatic, c)
+      arg.typ.sons = @[evaluated.typ]
+      arg.typ.n = evaluated
+      argType = arg.typ
+ 
+  var
+    r: TTypeRelation
+    a = if c.InTypeClass > 0: argType.skipTypes({tyTypeDesc})
         else: argType
-    fMaybeExpr = f.skipTypes({tyDistinct})
-
-  case fMaybeExpr.kind
-  of tyExpr:
-    if fMaybeExpr.sonsLen == 0:
-      r = isGeneric
-    else:
-      if a.kind == tyExpr:
-        internalAssert a.len > 0
-        r = typeRel(m, f.lastSon, a.lastSon)
-      else:
-        let match = matchTypeClass(m.bindings, fMaybeExpr, a)
-        if not match: r = isNone
-        else:
-          # XXX: Ideally, this should happen much earlier somewhere near 
-          # semOpAux, but to do that, we need to be able to query the 
-          # overload set to determine whether compile-time value is expected
-          # for the param before entering the full-blown sigmatch algorithm.
-          # This is related to the immediate pragma since querying the
-          # overload set could help there too.
-          var evaluated = c.semConstExpr(c, arg)
-          if evaluated != nil:
-            r = isGeneric
-            arg.typ = newTypeS(tyExpr, c)
-            arg.typ.sons = @[evaluated.typ]
-            arg.typ.n = evaluated
-        
-    if r == isGeneric:
-      put(m.bindings, f, arg.typ)
+ 
+  case fMaybeStatic.kind
   of tyTypeClass, tyParametricTypeClass:
-    if fMaybeExpr.n != nil:
-      let match = matchUserTypeClass(c, m, arg, fMaybeExpr, a)
+    if fMaybeStatic.n != nil:
+      let match = matchUserTypeClass(c, m, arg, fMaybeStatic, a)
       if match != nil:
         r = isGeneric
         arg = match
@@ -935,11 +990,14 @@ proc paramTypesMatchAux(c: PContext, m: var TCandidate, f, argType: PType,
         r = isNone
     else:
       r = typeRel(m, f, a)
+  of tyExpr:
+    r = isGeneric
+    put(m.bindings, f, arg.typ)
   else:
     r = typeRel(m, f, a)
 
   case r
-  of isConvertible: 
+  of isConvertible:
     inc(m.convMatches)
     result = implicitConv(nkHiddenStdConv, f, copyTree(arg), m, c)
   of isIntConv:
@@ -961,6 +1019,8 @@ proc paramTypesMatchAux(c: PContext, m: var TCandidate, f, argType: PType,
         result = argOrig[bodyPos]
       elif f.kind == tyTypeDesc:
         result = arg
+      elif f.kind == tyStatic:
+        result = arg.typ.n
       else:
         result = argOrig
     else:
@@ -1003,19 +1063,20 @@ proc paramTypesMatchAux(c: PContext, m: var TCandidate, f, argType: PType,
         else:
           result = userConvMatch(c, m, base(f), a, arg)
 
-proc paramTypesMatch*(c: PContext, m: var TCandidate, f, a: PType, 
+proc paramTypesMatch*(m: var TCandidate, f, a: PType,
                       arg, argOrig: PNode): PNode =
   if arg == nil or arg.kind notin nkSymChoices:
-    result = paramTypesMatchAux(c, m, f, a, arg, argOrig)
+    result = paramTypesMatchAux(m, f, a, arg, argOrig)
   else: 
     # CAUTION: The order depends on the used hashing scheme. Thus it is
     # incorrect to simply use the first fitting match. However, to implement
     # this correctly is inefficient. We have to copy `m` here to be able to
     # roll back the side effects of the unification algorithm.
+    let c = m.c
     var x, y, z: TCandidate
-    initCandidate(x, m.callee)
-    initCandidate(y, m.callee)
-    initCandidate(z, m.callee)
+    initCandidate(c, x, m.callee)
+    initCandidate(c, y, m.callee)
+    initCandidate(c, z, m.callee)
     x.calleeSym = m.calleeSym
     y.calleeSym = m.calleeSym
     z.calleeSym = m.calleeSym
@@ -1047,7 +1108,7 @@ proc paramTypesMatch*(c: PContext, m: var TCandidate, f, a: PType,
     else: 
       # only one valid interpretation found:
       markUsed(arg, arg.sons[best].sym)
-      result = paramTypesMatchAux(c, m, f, arg.sons[best].typ, arg.sons[best],
+      result = paramTypesMatchAux(m, f, arg.sons[best].typ, arg.sons[best],
                                   argOrig)
 
 proc setSon(father: PNode, at: int, son: PNode) = 
@@ -1138,7 +1199,7 @@ proc matchesAux(c: PContext, n, nOrig: PNode,
       m.baseTypeMatch = false
       n.sons[a].sons[1] = prepareOperand(c, formal.typ, n.sons[a].sons[1])
       n.sons[a].typ = n.sons[a].sons[1].typ
-      var arg = paramTypesMatch(c, m, formal.typ, n.sons[a].typ,
+      var arg = paramTypesMatch(m, formal.typ, n.sons[a].typ,
                                 n.sons[a].sons[1], nOrig.sons[a].sons[1])
       if arg == nil:
         m.state = csNoMatch
@@ -1168,7 +1229,7 @@ proc matchesAux(c: PContext, n, nOrig: PNode,
         elif formal != nil:
           m.baseTypeMatch = false
           n.sons[a] = prepareOperand(c, formal.typ, n.sons[a])
-          var arg = paramTypesMatch(c, m, formal.typ, n.sons[a].typ,
+          var arg = paramTypesMatch(m, formal.typ, n.sons[a].typ,
                                     n.sons[a], nOrig.sons[a])
           if (arg != nil) and m.baseTypeMatch and (container != nil):
             addSon(container, arg)
@@ -1191,7 +1252,7 @@ proc matchesAux(c: PContext, n, nOrig: PNode,
           return 
         m.baseTypeMatch = false
         n.sons[a] = prepareOperand(c, formal.typ, n.sons[a])
-        var arg = paramTypesMatch(c, m, formal.typ, n.sons[a].typ,
+        var arg = paramTypesMatch(m, formal.typ, n.sons[a].typ,
                                   n.sons[a], nOrig.sons[a])
         if arg == nil:
           m.state = csNoMatch
@@ -1245,8 +1306,8 @@ proc matches*(c: PContext, n, nOrig: PNode, m: var TCandidate) =
 
 proc argtypeMatches*(c: PContext, f, a: PType): bool =
   var m: TCandidate
-  initCandidate(m, f)
-  let res = paramTypesMatch(c, m, f, a, ast.emptyNode, nil)
+  initCandidate(c, m, f)
+  let res = paramTypesMatch(m, f, a, ast.emptyNode, nil)
   #instantiateGenericConverters(c, res, m)
   # XXX this is used by patterns.nim too; I think it's better to not
   # instantiate generic converters for that
@@ -1308,7 +1369,7 @@ tests:
 
     setup:
       var c: TCandidate
-      InitCandidate(c, nil)
+      InitCandidate(nil, c, nil)
 
     template yes(x, y) =
       test astToStr(x) & " is " & astToStr(y):
diff --git a/compiler/suggest.nim b/compiler/suggest.nim
index 06d1b28d2..1fde831b7 100644
--- a/compiler/suggest.nim
+++ b/compiler/suggest.nim
@@ -119,7 +119,7 @@ proc argsFit(c: PContext, candidate: PSym, n, nOrig: PNode): bool =
   case candidate.kind 
   of OverloadableSyms:
     var m: TCandidate
-    initCandidate(m, candidate, nil)
+    initCandidate(c, m, candidate, nil)
     sigmatch.partialMatch(c, n, nOrig, m)
     result = m.state != csNoMatch
   else:
diff --git a/compiler/types.nim b/compiler/types.nim
index 779a649a7..36c9f1934 100644
--- a/compiler/types.nim
+++ b/compiler/types.nim
@@ -10,7 +10,7 @@
 # this module contains routines for accessing and iterating over types
 
 import 
-  intsets, ast, astalgo, trees, msgs, strutils, platform
+  intsets, ast, astalgo, trees, msgs, strutils, platform, renderer
 
 proc firstOrd*(t: PType): BiggestInt
 proc lastOrd*(t: PType): BiggestInt
@@ -64,7 +64,6 @@ const
   typedescPtrs* = abstractPtrs + {tyTypeDesc}
   typedescInst* = abstractInst + {tyTypeDesc}
 
-proc skipTypes*(t: PType, kinds: TTypeKinds): PType
 proc containsObject*(t: PType): bool
 proc containsGarbageCollectedRef*(typ: PType): bool
 proc containsHiddenPointer*(typ: PType): bool
@@ -148,10 +147,6 @@ proc skipGeneric(t: PType): PType =
   result = t
   while result.kind == tyGenericInst: result = lastSon(result)
       
-proc skipTypes(t: PType, kinds: TTypeKinds): PType = 
-  result = t
-  while result.kind in kinds: result = lastSon(result)
-  
 proc isOrdinalType(t: PType): bool =
   assert(t != nil)
   # caution: uint, uint64 are no ordinal types!
@@ -410,18 +405,8 @@ const
     "uint", "uint8", "uint16", "uint32", "uint64",
     "bignum", "const ",
     "!", "varargs[$1]", "iter[$1]", "Error Type", "TypeClass",
-    "ParametricTypeClass", "and", "or", "not", "any"]
-
-proc consToStr(t: PType): string =
-  if t.len > 0: result = t.typeToString
-  else: result = typeToStr[t.kind].strip
-
-proc constraintsToStr(t: PType): string =
-  let sep = if tfAny in t.flags: " or " else: " and "
-  result = ""
-  for i in countup(0, t.len - 1):
-    if i > 0: result.add(sep)
-    result.add(t.sons[i].consToStr)
+    "ParametricTypeClass", "BuiltInTypeClass", "CompositeTypeClass",
+    "and", "or", "not", "any", "static", "TypeFromExpr"]
 
 proc typeToString(typ: PType, prefer: TPreferedDesc = preferName): string =
   var t = typ
@@ -445,16 +430,26 @@ proc typeToString(typ: PType, prefer: TPreferedDesc = preferName): string =
     add(result, ']')
   of tyTypeDesc:
     if t.len == 0: result = "typedesc"
-    else: result = "typedesc[" & constraintsToStr(t) & "]"
+    else: result = "typedesc[" & typeToString(t.sons[0]) & "]"
+  of tyStatic:
+    InternalAssert t.len > 0
+    result = "static[" & typeToString(t.sons[0]) & "]"
   of tyTypeClass:
-    if t.n != nil: return t.sym.owner.name.s
-    case t.len
-    of 0: result = "typeclass[]"
-    of 1: result = "typeclass[" & consToStr(t.sons[0]) & "]"
-    else: result = constraintsToStr(t)
+    InternalAssert t.sym != nil and t.sym.owner != nil
+    return t.sym.owner.name.s
+  of tyBuiltInTypeClass:
+    return "TypeClass"
+  of tyAnd:
+    result = typeToString(t.sons[0]) & " and " & typeToString(t.sons[1])
+  of tyOr:
+    result = typeToString(t.sons[0]) & " and " & typeToString(t.sons[1])
+  of tyNot:
+    result = "not " & typeToString(t.sons[0])
   of tyExpr:
-    if t.len == 0: result = "expr"
-    else: result = "expr[" & constraintsToStr(t) & "]"
+    InternalAssert t.len == 0
+    result = "expr"
+  of tyFromExpr:
+    result = renderTree(t.n)
   of tyArray: 
     if t.sons[0].kind == tyRange: 
       result = "array[" & rangeToStr(t.sons[0].n) & ", " &
@@ -607,8 +602,11 @@ type
     dcEqOrDistinctOf       ## a equals b or a is distinct of b
 
   TTypeCmpFlag* = enum
-    IgnoreTupleFields,
-    TypeDescExactMatch,
+    IgnoreTupleFields
+    IgnoreCC
+    ExactTypeDescValues
+    ExactGenericParams
+    ExactConstraints
     AllowCommonBase
 
   TTypeCmpFlags* = set[TTypeCmpFlag]
@@ -638,18 +636,20 @@ proc sameTypeOrNilAux(a, b: PType, c: var TSameTypeClosure): bool =
     if a == nil or b == nil: result = false
     else: result = sameTypeAux(a, b, c)
 
+proc sameType*(a, b: PType, flags: TTypeCmpFlags = {}): bool =
+  var c = initSameTypeClosure()
+  c.flags = flags
+  result = sameTypeAux(a, b, c)
+
 proc sameTypeOrNil*(a, b: PType, flags: TTypeCmpFlags = {}): bool =
   if a == b:
     result = true
-  else: 
+  else:
     if a == nil or b == nil: result = false
-    else:
-      var c = initSameTypeClosure()
-      c.flags = flags
-      result = sameTypeAux(a, b, c)
+    else: result = sameType(a, b, flags)
 
 proc equalParam(a, b: PSym): TParamsEquality = 
-  if sameTypeOrNil(a.typ, b.typ, {TypeDescExactMatch}) and
+  if sameTypeOrNil(a.typ, b.typ, {ExactTypeDescValues}) and
       exprStructuralEquivalent(a.constraint, b.constraint):
     if a.ast == b.ast: 
       result = paramsEqual
@@ -662,7 +662,15 @@ proc equalParam(a, b: PSym): TParamsEquality =
       result = paramsIncompatible
   else:
     result = paramsNotEqual
-  
+
+proc sameConstraints(a, b: PNode): bool =
+  internalAssert a.len == b.len
+  for i in 1 .. <a.len:
+    if not exprStructuralEquivalent(a[i].sym.constraint,
+                                    b[i].sym.constraint):
+      return false
+  return true
+
 proc equalParams(a, b: PNode): TParamsEquality = 
   result = paramsEqual
   var length = sonsLen(a)
@@ -685,7 +693,7 @@ proc equalParams(a, b: PNode): TParamsEquality =
         return paramsNotEqual # paramsIncompatible;
       # continue traversal! If not equal, we can return immediately; else
       # it stays incompatible
-    if not sameTypeOrNil(a.sons[0].typ, b.sons[0].typ, {TypeDescExactMatch}):
+    if not sameTypeOrNil(a.sons[0].typ, b.sons[0].typ, {ExactTypeDescValues}):
       if (a.sons[0].typ == nil) or (b.sons[0].typ == nil): 
         result = paramsNotEqual # one proc has a result, the other not is OK
       else: 
@@ -752,9 +760,9 @@ 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)
@@ -829,9 +837,9 @@ proc sameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
       if a.kind != b.kind: return false  
   case a.kind
   of tyEmpty, tyChar, tyBool, tyNil, tyPointer, tyString, tyCString,
-     tyInt..tyBigNum, tyStmt:
+     tyInt..tyBigNum, tyStmt, tyExpr:
     result = sameFlags(a, b)
-  of tyExpr:
+  of tyStatic, tyFromExpr:
     result = exprStructuralEquivalent(a.n, b.n) and sameFlags(a, b)
   of tyObject:
     ifFastObjectTypeCheckFailed(a, b):
@@ -855,19 +863,25 @@ proc sameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
     result = sameTypeAux(lastSon(a), lastSon(b), c)
   of tyTypeDesc:
     if c.cmp == dcEqIgnoreDistinct: result = false
-    elif TypeDescExactMatch in c.flags:
+    elif ExactTypeDescValues in c.flags:
       cycleCheck()
       result = sameChildrenAux(x, y, c) and sameFlags(a, b)
     else:
       result = sameFlags(a, b)
-  of tyGenericParam, tyGenericInvokation, tyGenericBody, tySequence,
+  of tyGenericParam:
+    result = sameChildrenAux(a, b, c) and sameFlags(a, b)
+    if result and ExactGenericParams in c.flags:
+      result = a.sym.position == b.sym.position
+  of tyGenericInvokation, tyGenericBody, tySequence,
      tyOpenArray, tySet, tyRef, tyPtr, tyVar, tyArrayConstr,
      tyArray, tyProc, tyConst, tyMutable, tyVarargs, tyIter,
      tyOrdinal, tyTypeClasses:
-    cycleCheck()    
+    cycleCheck()
+    if a.kind == tyTypeClass and a.n != nil: return a.n == b.n
     result = sameChildrenAux(a, b, c) and sameFlags(a, b)
     if result and a.kind == tyProc:
-      result = a.callConv == b.callConv
+      result = ((IgnoreCC in c.flags) or a.callConv == b.callConv) and
+               ((ExactConstraints notin c.flags) or sameConstraints(a.n, b.n))
   of tyRange:
     cycleCheck()
     result = sameTypeOrNilAux(a.sons[0], b.sons[0], c) and
@@ -875,10 +889,6 @@ proc sameTypeAux(x, y: PType, c: var TSameTypeClosure): bool =
         sameValue(a.n.sons[1], b.n.sons[1])
   of tyNone: result = false  
 
-proc sameType*(x, y: PType): bool =
-  var c = initSameTypeClosure()
-  result = sameTypeAux(x, y, c)
-
 proc sameBackendType*(x, y: PType): bool =
   var c = initSameTypeClosure()
   c.flags.incl IgnoreTupleFields
@@ -976,42 +986,6 @@ proc isGenericAlias*(t: PType): bool =
 proc skipGenericAlias*(t: PType): PType =
   return if t.isGenericAlias: t.lastSon else: t
 
-proc matchTypeClass*(bindings: var TIdTable, typeClass, t: PType): bool =
-  for i in countup(0, typeClass.sonsLen - 1):
-    let req = typeClass.sons[i]
-    var match = req.kind == skipTypes(t, {tyRange, tyGenericInst}).kind
-
-    if not match:
-      case req.kind
-      of tyGenericBody:
-        if t.kind == tyGenericInst and t.sons[0] == req:
-          match = true
-          idTablePut(bindings, typeClass, t)
-      of tyTypeClass:
-        match = matchTypeClass(bindings, req, t)
-      elif t.kind == tyTypeClass:
-        match = matchTypeClass(bindings, t, req)
-          
-    elif t.kind in {tyObject} and req.len != 0:
-      # empty 'object' is fine as constraint in a type class
-      match = sameType(t, req)
-
-    if tfAny in typeClass.flags:
-      if match: return true
-    else:
-      if not match: return false
-
-  # if the loop finished without returning, either all constraints matched
-  # or none of them matched.
-  result = if tfAny in typeClass.flags: false else: true
-  if result == true:
-    idTablePut(bindings, typeClass, t)
-
-proc matchTypeClass*(typeClass, typ: PType): bool =
-  var bindings: TIdTable
-  initIdTable(bindings)
-  result = matchTypeClass(bindings, typeClass, typ)
-
 proc typeAllowedAux(marker: var TIntSet, typ: PType, kind: TSymKind,
                     flags: TTypeAllowedFlags = {}): bool =
   assert(kind in {skVar, skLet, skConst, skParam, skResult})
@@ -1039,14 +1013,15 @@ proc typeAllowedAux(marker: var TIntSet, typ: PType, kind: TSymKind,
       if not result: break 
     if result and t.sons[0] != nil:
       result = typeAllowedAux(marker, t.sons[0], skResult, flags)
-  of tyExpr, tyStmt, tyTypeDesc:
+  of tyExpr, tyStmt, tyTypeDesc, tyStatic:
     result = true
     # XXX er ... no? these should not be allowed!
   of tyEmpty:
     result = taField in flags
   of tyTypeClasses:
     result = true
-  of tyGenericBody, tyGenericParam, tyForward, tyNone, tyGenericInvokation:
+  of tyGenericBody, tyGenericParam, tyGenericInvokation,
+     tyNone, tyForward, tyFromExpr:
     result = false
   of tyNil:
     result = kind == skConst
@@ -1133,18 +1108,22 @@ proc computeRecSizeAux(n: PNode, a, currOffset: var BiggestInt): BiggestInt =
     a = 1
     result = - 1
 
-proc computeSizeAux(typ: PType, a: var BiggestInt): BiggestInt = 
+const 
+  szIllegalRecursion* = -2
+  szUnknownSize* = -1
+
+proc computeSizeAux(typ: PType, a: var BiggestInt): BiggestInt =
   var res, maxAlign, length, currOffset: BiggestInt
-  if typ.size == - 2: 
+  if typ.size == szIllegalRecursion:
     # we are already computing the size of the type
     # --> illegal recursion in type
-    return - 2
-  if typ.size >= 0: 
+    return szIllegalRecursion
+  if typ.size >= 0:
     # size already computed
     result = typ.size
     a = typ.align
     return 
-  typ.size = - 2              # mark as being computed
+  typ.size = szIllegalRecursion # mark as being computed
   case typ.kind
   of tyInt, tyUInt: 
     result = intSize
@@ -1175,8 +1154,10 @@ proc computeSizeAux(typ: PType, a: var BiggestInt): BiggestInt =
      tyBigNum: 
     result = ptrSize
     a = result
-  of tyArray, tyArrayConstr: 
-    result = lengthOrd(typ.sons[0]) * computeSizeAux(typ.sons[1], a)
+  of tyArray, tyArrayConstr:
+    let elemSize = computeSizeAux(typ.sons[1], a)
+    if elemSize < 0: return elemSize
+    result = lengthOrd(typ.sons[0]) * elemSize
   of tyEnum: 
     if firstOrd(typ) < 0: 
       result = 4              # use signed int32
@@ -1227,11 +1208,12 @@ proc computeSizeAux(typ: PType, a: var BiggestInt): BiggestInt =
   of tyGenericInst, tyDistinct, tyGenericBody, tyMutable, tyConst, tyIter:
     result = computeSizeAux(lastSon(typ), a)
   of tyTypeDesc:
-    result = (if typ.len == 1: computeSizeAux(typ.sons[0], a) else: -1)
-  of tyProxy: result = 1
+    result = if typ.len == 1: computeSizeAux(typ.sons[0], a)
+             else: szUnknownSize
+  of tyForward: return szIllegalRecursion
   else:
     #internalError("computeSizeAux()")
-    result = - 1
+    result = szUnknownSize
   typ.size = result
   typ.align = int(a)
 
@@ -1248,9 +1230,9 @@ proc getSize(typ: PType): BiggestInt =
   result = computeSize(typ)
   if result < 0: internalError("getSize: " & $typ.kind)
 
-  
-proc containsGenericTypeIter(t: PType, closure: PObject): bool = 
-  result = t.kind in GenericTypes
+proc containsGenericTypeIter(t: PType, closure: PObject): bool =
+  result = t.kind in GenericTypes + tyTypeClasses + {tyTypeDesc,tyFromExpr} or
+           t.kind == tyStatic and t.n == nil
 
 proc containsGenericType*(t: PType): bool = 
   result = iterOverType(t, containsGenericTypeIter, nil)
@@ -1315,7 +1297,7 @@ proc compatibleEffects*(formal, actual: PType): bool =
   result = true
 
 proc isCompileTimeOnly*(t: PType): bool {.inline.} =
-  result = t.kind in {tyTypeDesc, tyExpr}
+  result = t.kind in {tyTypeDesc, tyStatic}
 
 proc containsCompileTimeOnly*(t: PType): bool =
   if isCompileTimeOnly(t): return true
diff --git a/compiler/vm.nim b/compiler/vm.nim
index 94891feb2..a670e5bd0 100644
--- a/compiler/vm.nim
+++ b/compiler/vm.nim
@@ -791,7 +791,8 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): PNode =
       decodeBC(nkIntLit)
       let t1 = regs[rb].typ.skipTypes({tyTypeDesc})
       let t2 = c.types[regs[rc].intVal.int]
-      let match = if t2.kind == tyTypeClass: matchTypeClass(t2, t1)
+      # XXX: This should use the standard isOpImpl
+      let match = if t2.kind == tyTypeClass: true
                   else: sameType(t1, t2)
       regs[ra].intVal = ord(match)
     of opcSetLenSeq:
diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim
index 563dbc6d1..6389d0508 100644
--- a/compiler/vmgen.nim
+++ b/compiler/vmgen.nim
@@ -832,7 +832,7 @@ proc genMagic(c: PCtx; n: PNode; dest: var TDest) =
 
 const
   atomicTypes = {tyBool, tyChar,
-    tyExpr, tyStmt, tyTypeDesc,
+    tyExpr, tyStmt, tyTypeDesc, tyStatic,
     tyEnum,
     tyOrdinal,
     tyRange,
@@ -1039,8 +1039,8 @@ proc getNullValue(typ: PType, info: TLineInfo): PNode =
     result = newNodeIT(nkUIntLit, info, t)
   of tyFloat..tyFloat128: 
     result = newNodeIT(nkFloatLit, info, t)
-  of tyVar, tyPointer, tyPtr, tyCString, tySequence, tyString, tyExpr, 
-     tyStmt, tyTypeDesc, tyRef:
+  of tyVar, tyPointer, tyPtr, tyCString, tySequence, tyString, tyExpr,
+     tyStmt, tyTypeDesc, tyStatic, tyRef:
     result = newNodeIT(nkNilLit, info, t)
   of tyProc:
     if t.callConv != ccClosure: