allow 'mixin' in generics

compiler/condsyms.nim

@@ -58,6 +58,7 @@ proc InitDefines*() =
   # for bootstrapping purposes and old code:
   DefineSymbol("nimhygiene")
   DefineSymbol("niminheritable")
+  DefineSymbol("nimmixin")
   
   # add platform specific symbols:
   case targetCPU

compiler/semgnrc.nim

@@ -32,12 +32,12 @@ proc getIdentNode(n: PNode): PNode =
     result = n
 
 proc semGenericStmt(c: PContext, n: PNode, flags: TSemGenericFlags,
-                    toBind: var TIntSet): PNode
+                    ctx: var TIntSet): PNode
 proc semGenericStmtScope(c: PContext, n: PNode, 
                          flags: TSemGenericFlags,
-                         toBind: var TIntSet): PNode = 
+                         ctx: var TIntSet): PNode = 
   openScope(c.tab)
-  result = semGenericStmt(c, n, flags, toBind)
+  result = semGenericStmt(c, n, flags, ctx)
   closeScope(c.tab)
 
 template macroToExpand(s: expr): expr =
@@ -73,20 +73,35 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym): PNode =
       result = n
   else: result = newSymNode(s, n.info)
   
+proc semMixinStmt(c: PContext, n: PNode, toMixin: var TIntSet): PNode =
+  for i in 0 .. < n.len:
+    toMixin.incl(considerAcc(n.sons[i]).id)
+  result = newNodeI(nkNilLit, n.info)
+
+proc Lookup(c: PContext, n: PNode, flags: TSemGenericFlags, 
+            ctx: var TIntSet): PNode =
+  result = n
+  let ident = considerAcc(n)
+  var s = SymtabGet(c.Tab, ident)
+  if s == nil:
+    if ident.id notin ctx and withinMixin notin flags:
+      localError(n.info, errUndeclaredIdentifier, ident.s)
+  else:
+    if withinMixin in flags:
+      result = symChoice(c, n, s, scClosed)
+    elif s.name.id in ctx:
+      result = symChoice(c, n, s, scForceOpen)
+    else:
+      result = semGenericStmtSymbol(c, n, s)
+  # else: leave as nkIdent
+  
 proc semGenericStmt(c: PContext, n: PNode, 
-                    flags: TSemGenericFlags, toBind: var TIntSet): PNode = 
+                    flags: TSemGenericFlags, ctx: var TIntSet): PNode =
   result = n
   if gCmd == cmdIdeTools: suggestStmt(c, n)
   case n.kind
   of nkIdent, nkAccQuoted:
-    var s = SymtabGet(c.Tab, n.ident)
-    if s == nil:
-      if withinMixin notin flags:
-        localError(n.info, errUndeclaredIdentifier, n.ident.s)
-    else:
-      if withinBind in flags or s.id in toBind:
-        result = symChoice(c, n, s, scClosed)
-      else: result = semGenericStmtSymbol(c, n, s)
+    result = Lookup(c, n, flags, ctx)
   of nkDotExpr:
     let luf = if withinMixin notin flags: {checkUndeclared} else: {}
     var s = QualifiedLookUp(c, n, luf)
@@ -101,15 +116,19 @@ proc semGenericStmt(c: PContext, n: PNode,
     # the owner of the symbol! What we need to do is to copy the symbol
     # in the generic instantiation process...
     nil
-  of nkBind: 
-    result = semGenericStmt(c, n.sons[0], flags+{withinBind}, toBind)
-  of nkBindStmt:
-    result = semBindStmt(c, n, toBind)
+  of nkBind:
+    result = semGenericStmt(c, n.sons[0], flags+{withinBind}, ctx)
+  of nkMixinStmt:
+    result = semMixinStmt(c, n, ctx)
   of nkCall, nkHiddenCallConv, nkInfix, nkPrefix, nkCommand, nkCallStrLit: 
     # check if it is an expression macro:
     checkMinSonsLen(n, 1)
-    let luf = if withinMixin notin flags: {checkUndeclared} else: {}
-    var s = qualifiedLookup(c, n.sons[0], luf)
+    let fn = n.sons[0]
+    var s = qualifiedLookup(c, fn, {})
+    if s == nil and withinMixin notin flags and
+        fn.kind in {nkIdent, nkAccQuoted} and considerAcc(fn).id notin ctx:
+      localError(n.info, errUndeclaredIdentifier, fn.renderTree)
+    
     var first = 0
     var isDefinedMagic = false
     if s != nil: 
@@ -152,54 +171,54 @@ proc semGenericStmt(c: PContext, n: PNode,
     # is not exported and yet the generic 'threadProcWrapper' works correctly.
     let flags = if isDefinedMagic: flags+{withinMixin} else: flags
     for i in countup(first, sonsLen(result) - 1):
-      result.sons[i] = semGenericStmt(c, result.sons[i], flags, toBind)
+      result.sons[i] = semGenericStmt(c, result.sons[i], flags, ctx)
   of nkIfStmt: 
     for i in countup(0, sonsLen(n)-1): 
-      n.sons[i] = semGenericStmtScope(c, n.sons[i], flags, toBind)
+      n.sons[i] = semGenericStmtScope(c, n.sons[i], flags, ctx)
   of nkWhenStmt:
     for i in countup(0, sonsLen(n)-1):
-      n.sons[i] = semGenericStmt(c, n.sons[i], flags+{withinMixin}, toBind)
+      n.sons[i] = semGenericStmt(c, n.sons[i], flags+{withinMixin}, ctx)
   of nkWhileStmt: 
     openScope(c.tab)
     for i in countup(0, sonsLen(n)-1): 
-      n.sons[i] = semGenericStmt(c, n.sons[i], flags, toBind)
+      n.sons[i] = semGenericStmt(c, n.sons[i], flags, ctx)
     closeScope(c.tab)
   of nkCaseStmt: 
     openScope(c.tab)
-    n.sons[0] = semGenericStmt(c, n.sons[0], flags, toBind)
+    n.sons[0] = semGenericStmt(c, n.sons[0], flags, ctx)
     for i in countup(1, sonsLen(n)-1): 
       var a = n.sons[i]
       checkMinSonsLen(a, 1)
       var L = sonsLen(a)
       for j in countup(0, L-2): 
-        a.sons[j] = semGenericStmt(c, a.sons[j], flags, toBind)
-      a.sons[L - 1] = semGenericStmtScope(c, a.sons[L-1], flags, toBind)
+        a.sons[j] = semGenericStmt(c, a.sons[j], flags, ctx)
+      a.sons[L - 1] = semGenericStmtScope(c, a.sons[L-1], flags, ctx)
     closeScope(c.tab)
   of nkForStmt, nkParForStmt: 
     var L = sonsLen(n)
     openScope(c.tab)
-    n.sons[L - 2] = semGenericStmt(c, n.sons[L-2], flags, toBind)
+    n.sons[L - 2] = semGenericStmt(c, n.sons[L-2], flags, ctx)
     for i in countup(0, L - 3):
       addPrelimDecl(c, newSymS(skUnknown, n.sons[i], c))
-    n.sons[L - 1] = semGenericStmt(c, n.sons[L-1], flags, toBind)
+    n.sons[L - 1] = semGenericStmt(c, n.sons[L-1], flags, ctx)
     closeScope(c.tab)
   of nkBlockStmt, nkBlockExpr, nkBlockType: 
     checkSonsLen(n, 2)
     openScope(c.tab)
     if n.sons[0].kind != nkEmpty: 
       addPrelimDecl(c, newSymS(skUnknown, n.sons[0], c))
-    n.sons[1] = semGenericStmt(c, n.sons[1], flags, toBind)
+    n.sons[1] = semGenericStmt(c, n.sons[1], flags, ctx)
     closeScope(c.tab)
   of nkTryStmt: 
     checkMinSonsLen(n, 2)
-    n.sons[0] = semGenericStmtScope(c, n.sons[0], flags, toBind)
+    n.sons[0] = semGenericStmtScope(c, n.sons[0], flags, ctx)
     for i in countup(1, sonsLen(n)-1): 
       var a = n.sons[i]
       checkMinSonsLen(a, 1)
       var L = sonsLen(a)
       for j in countup(0, L-2): 
-        a.sons[j] = semGenericStmt(c, a.sons[j], flags+{withinTypeDesc}, toBind)
-      a.sons[L-1] = semGenericStmtScope(c, a.sons[L-1], flags, toBind)
+        a.sons[j] = semGenericStmt(c, a.sons[j], flags+{withinTypeDesc}, ctx)
+      a.sons[L-1] = semGenericStmtScope(c, a.sons[L-1], flags, ctx)
   of nkVarSection, nkLetSection: 
     for i in countup(0, sonsLen(n) - 1): 
       var a = n.sons[i]
@@ -208,8 +227,8 @@ proc semGenericStmt(c: PContext, n: PNode,
       checkMinSonsLen(a, 3)
       var L = sonsLen(a)
       a.sons[L-2] = semGenericStmt(c, a.sons[L-2], flags+{withinTypeDesc}, 
-                                   toBind)
-      a.sons[L-1] = semGenericStmt(c, a.sons[L-1], flags, toBind)
+                                   ctx)
+      a.sons[L-1] = semGenericStmt(c, a.sons[L-1], flags, ctx)
       for j in countup(0, L-3):
         addPrelimDecl(c, newSymS(skUnknown, getIdentNode(a.sons[j]), c))
   of nkGenericParams: 
@@ -219,7 +238,7 @@ proc semGenericStmt(c: PContext, n: PNode,
       checkMinSonsLen(a, 3)
       var L = sonsLen(a)
       a.sons[L-2] = semGenericStmt(c, a.sons[L-2], flags+{withinTypeDesc}, 
-                                   toBind) 
+                                   ctx) 
       # do not perform symbol lookup for default expressions 
       for j in countup(0, L-3): 
         addPrelimDecl(c, newSymS(skUnknown, getIdentNode(a.sons[j]), c))
@@ -230,8 +249,8 @@ proc semGenericStmt(c: PContext, n: PNode,
       if (a.kind != nkConstDef): IllFormedAst(a)
       checkSonsLen(a, 3)
       addPrelimDecl(c, newSymS(skUnknown, getIdentNode(a.sons[0]), c))
-      a.sons[1] = semGenericStmt(c, a.sons[1], flags+{withinTypeDesc}, toBind)
-      a.sons[2] = semGenericStmt(c, a.sons[2], flags, toBind)
+      a.sons[1] = semGenericStmt(c, a.sons[1], flags+{withinTypeDesc}, ctx)
+      a.sons[2] = semGenericStmt(c, a.sons[2], flags, ctx)
   of nkTypeSection: 
     for i in countup(0, sonsLen(n) - 1): 
       var a = n.sons[i]
@@ -246,15 +265,15 @@ proc semGenericStmt(c: PContext, n: PNode,
       checkSonsLen(a, 3)
       if a.sons[1].kind != nkEmpty: 
         openScope(c.tab)
-        a.sons[1] = semGenericStmt(c, a.sons[1], flags, toBind)
-        a.sons[2] = semGenericStmt(c, a.sons[2], flags+{withinTypeDesc}, toBind)
+        a.sons[1] = semGenericStmt(c, a.sons[1], flags, ctx)
+        a.sons[2] = semGenericStmt(c, a.sons[2], flags+{withinTypeDesc}, ctx)
         closeScope(c.tab)
       else: 
-        a.sons[2] = semGenericStmt(c, a.sons[2], flags+{withinTypeDesc}, toBind)
+        a.sons[2] = semGenericStmt(c, a.sons[2], flags+{withinTypeDesc}, ctx)
   of nkEnumTy: 
     if n.sonsLen > 0:
       if n.sons[0].kind != nkEmpty: 
-        n.sons[0] = semGenericStmt(c, n.sons[0], flags+{withinTypeDesc}, toBind)
+        n.sons[0] = semGenericStmt(c, n.sons[0], flags+{withinTypeDesc}, ctx)
       for i in countup(1, sonsLen(n) - 1): 
         var a: PNode
         case n.sons[i].kind
@@ -267,15 +286,15 @@ proc semGenericStmt(c: PContext, n: PNode,
   of nkFormalParams: 
     checkMinSonsLen(n, 1)
     if n.sons[0].kind != nkEmpty: 
-      n.sons[0] = semGenericStmt(c, n.sons[0], flags+{withinTypeDesc}, toBind)
+      n.sons[0] = semGenericStmt(c, n.sons[0], flags+{withinTypeDesc}, ctx)
     for i in countup(1, sonsLen(n) - 1): 
       var a = n.sons[i]
       if (a.kind != nkIdentDefs): IllFormedAst(a)
       checkMinSonsLen(a, 3)
       var L = sonsLen(a)
       a.sons[L-2] = semGenericStmt(c, a.sons[L-2], flags+{withinTypeDesc}, 
-                                   toBind)
-      a.sons[L-1] = semGenericStmt(c, a.sons[L-1], flags, toBind)
+                                   ctx)
+      a.sons[L-1] = semGenericStmt(c, a.sons[L-1], flags, ctx)
       for j in countup(0, L-3): 
         addPrelimDecl(c, newSymS(skUnknown, getIdentNode(a.sons[j]), c))
   of nkProcDef, nkMethodDef, nkConverterDef, nkMacroDef, nkTemplateDef, 
@@ -285,22 +304,22 @@ proc semGenericStmt(c: PContext, n: PNode,
       addPrelimDecl(c, newSymS(skUnknown, getIdentNode(n.sons[0]), c))
     openScope(c.tab)
     n.sons[genericParamsPos] = semGenericStmt(c, n.sons[genericParamsPos], 
-                                              flags, toBind)
+                                              flags, ctx)
     if n.sons[paramsPos].kind != nkEmpty: 
       if n.sons[paramsPos].sons[0].kind != nkEmpty: 
         addPrelimDecl(c, newSym(skUnknown, getIdent("result"), nil, n.info))
-      n.sons[paramsPos] = semGenericStmt(c, n.sons[paramsPos], flags, toBind)
-    n.sons[pragmasPos] = semGenericStmt(c, n.sons[pragmasPos], flags, toBind)
+      n.sons[paramsPos] = semGenericStmt(c, n.sons[paramsPos], flags, ctx)
+    n.sons[pragmasPos] = semGenericStmt(c, n.sons[pragmasPos], flags, ctx)
     var body: PNode
     if n.sons[namePos].kind == nkSym: body = n.sons[namePos].sym.getBody
     else: body = n.sons[bodyPos]
-    n.sons[bodyPos] = semGenericStmtScope(c, body, flags, toBind)
+    n.sons[bodyPos] = semGenericStmtScope(c, body, flags, ctx)
     closeScope(c.tab)
   of nkPragma, nkPragmaExpr: nil
   of nkExprColonExpr:
     checkMinSonsLen(n, 2)
-    result.sons[1] = semGenericStmt(c, n.sons[1], flags, toBind)
-  else: 
+    result.sons[1] = semGenericStmt(c, n.sons[1], flags, ctx)
+  else:
     for i in countup(0, sonsLen(n) - 1): 
-      result.sons[i] = semGenericStmt(c, n.sons[i], flags, toBind)
+      result.sons[i] = semGenericStmt(c, n.sons[i], flags, ctx)
   

compiler/semtempl.nim

@@ -90,29 +90,6 @@ proc semBindStmt(c: PContext, n: PNode, toBind: var TIntSet): PNode =
     else:
       illFormedAst(a)
   result = newNodeI(nkNilLit, n.info)
-
-when false:
-  # not active before 0.9.0 is out
-  proc semMixinStmt(c: PContext, n: PNode, toMixin: var TIntSet): PNode =
-    for i in 0 .. < n.len:
-      var a = n.sons[i]
-      # If 'a' is an overloaded symbol, we used to use the first symbol
-      # as a 'witness' and use the fact that subsequent lookups will yield
-      # the same symbol!
-      # This is however not true anymore for hygienic templates as semantic
-      # processing for them changes the symbol table...
-      let s = QualifiedLookUp(c, a)
-      if s != nil:
-        # we need to mark all symbols:
-        let sc = symChoice(c, n, s, scForceOpen)
-        if sc.kind == nkSym:
-          toMixin.incl(sc.sym.id)
-        else:
-          for x in items(sc): toMixin.incl(x.sym.id)
-      else:
-        # do nothing: identifiers are already not bound:
-        nil
-    result = newNodeI(nkNilLit, n.info)
   
 proc replaceIdentBySym(n: var PNode, s: PNode) =
   case n.kind

lib/system/arithm.nim

@@ -240,7 +240,7 @@ elif false: # asmVersion and (defined(gcc) or defined(llvm_gcc)):
             :"%edx"
     """
 
-# Platform independant versions of the above (slower!)
+# Platform independent versions of the above (slower!)
 when not defined(addInt):
   proc addInt(a, b: int): int {.compilerProc, inline.} =
     result = a +% b

lib/system/assign.nim

@@ -144,11 +144,17 @@ proc objectInit(dest: Pointer, typ: PNimType) =
   
 # ---------------------- assign zero -----------------------------------------
 
-# dummy declaration; XXX we need 'mixin' here
-proc destroy(x: int) = nil
-proc nimDestroyRange*[T](r: T) =
-  # internal proc used for destroying sequences and arrays
-  for i in countup(0, r.len - 1): destroy(r[i])
+when not defined(nimmixin):
+  proc destroy(x: int) = nil
+  proc nimDestroyRange*[T](r: T) =
+    # internal proc used for destroying sequences and arrays
+    for i in countup(0, r.len - 1): destroy(r[i])
+else:
+  # XXX Why is this exported and no compilerproc?
+  proc nimDestroyRange*[T](r: T) =
+    # internal proc used for destroying sequences and arrays
+    mixin destroy
+    for i in countup(0, r.len - 1): destroy(r[i])
 
 proc genericReset(dest: Pointer, mt: PNimType) {.compilerProc.}
 proc genericResetAux(dest: Pointer, n: ptr TNimNode) =

todo.txt

@@ -1,6 +1,8 @@
 version 0.9.2
 =============
 
+- document 'mixin' for generics and symbol lookup rules; special rule 
+  for ``[]=``
 - implement the compiler as a service
 - implement for loop transformation for first class iterators
 - ``=`` should be overloadable; requires specialization for ``=``
@@ -65,7 +67,6 @@ version 0.9.XX
 - proc specialization in the code gen for write barrier specialization
 - tlastmod returns wrong results on BSD (Linux, MacOS X: works)
 - nested tuple unpacking; tuple unpacking in non-var-context
-- test branch coverage
 - make pegs support a compile-time option and make c2nim use regexes instead
   per default?
 - 'const' objects including case objects