fixes #1063

compiler/semtypes.nim

@@ -225,8 +225,18 @@ proc semArray(c: PContext, n: PNode, prev: PType): PType =
         # properly filled-out in semtypinst (see how tyStaticExpr
         # is handled there).
         indx = makeRangeWithStaticExpr(c, e)
-      else:
+      elif e.kind == nkIdent:
         indx = e.typ.skipTypes({tyTypeDesc})
+      else:
+        let x = semConstExpr(c, e)
+        if x.kind in {nkIntLit..nkUInt64Lit}:
+          indx = makeRangeType(c, 0, x.intVal-1, n.info, 
+                               x.typ.skipTypes({tyTypeDesc}))
+        else:
+          indx = x.typ.skipTypes({tyTypeDesc})
+          if not isOrdinalType(indx):
+            localError(n[1].info, errOrdinalTypeExpected)
+          #localError(n[1].info, errConstExprExpected)
     addSonSkipIntLit(result, indx)
     if indx.kind == tyGenericInst: indx = lastSon(indx)
     if indx.kind notin {tyGenericParam, tyStatic, tyFromExpr}:

compiler/vmgen.nim

@@ -1501,7 +1501,7 @@ proc gen(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags = {}) =
     else:
       localError(n.info, errGenerated, "VM is not allowed to 'cast'")
   else:
-    internalError n.info, "too implement " & $n.kind
+    internalError n.info, "cannot generate VM code for " & n.renderTree
 
 proc removeLastEof(c: PCtx) =
   let last = c.code.len-1