diff --git a/benchmark/parse.cpp b/benchmark/parse.cpp
index 18659b66..b1f4d7e2 100644
--- a/benchmark/parse.cpp
+++ b/benchmark/parse.cpp
@@ -99,14 +99,19 @@ void colorfuldisplay(ParsedJson &pj, const u8 *buf) {
 
 int main(int argc, char *argv[]) {
   bool verbose = false;
+  bool dump = false;
+
   int c;
 
-  while ((c = getopt (argc, argv, "v")) != -1)
+  while ((c = getopt (argc, argv, "vd")) != -1)
     switch (c)
       {
       case 'v':
         verbose = true;
         break;
+      case 'd':
+        dump = true;
+        break;
       default:
         abort ();
       }
@@ -235,7 +240,7 @@ int main(int argc, char *argv[]) {
   cout << "Min:  " << min_result << " bytes read: " << p.second
        << " Gigabytes/second: " << (p.second) / (min_result * 1000000000.0)
        << "\n";
-
+  if(dump) pj_ptr->dump_tapes();
   free(p.first);
   deallocate_ParsedJson(pj_ptr);
   if (!isok) {
diff --git a/src/stage34_unified.cpp b/src/stage34_unified.cpp
index bec8c0ad..323fd828 100644
--- a/src/stage34_unified.cpp
+++ b/src/stage34_unified.cpp
@@ -67,15 +67,22 @@ really_inline bool is_valid_null_atom(const u8 * loc) {
     return error == 0;
 }
 
+// Implemented using Labels as Values which works in GCC and CLANG,
+// but won't work in MSVC. This would need to be reimplemented differently
+// if one wants to be standard compliant.
 WARN_UNUSED
 bool unified_machine(const u8 *buf, size_t len, ParsedJson &pj) {
-    u32 i = 0;
-    u32 idx;
-    u8 c;
+    u32 i = 0; // index of the structural character (0,1,2,3...)
+    u32 idx; // location of the structural character in the input (buf)
+    u8 c; // used to track the (structural) character we are looking at, updated by UPDATE_CHAR macro
     u32 depth = START_DEPTH; // an arbitrary starting depth
-    void * ret_address[MAX_DEPTH];
+    void * ret_address[MAX_DEPTH]; // used to store "labels as value" (non-standard compiler extension)
+
+    // a call site is the start of either an object or an array ('[' or '{')
+    u32 last_loc = 0; // this is the location of the previous call site 
+    // (in the tape, at the given depth); 
+    // we only need one.
 
-    u32 last_loc = 0; // this is the location of the previous call site; only need one
     // We should also track the tape address of our containing
     // scope for two reasons. First, we will need to put an 
     // up pointer there at each call site so we can navigate