Debug dump improvements

dev/TODO.txt

@@ -8,6 +8,11 @@
     it make things harder to recognize without its namespace in front.
     Really, don't put things in a namespace if you don't effectively want to make it part of the name.
 
+- Debug dump improvements:
+  - automatically zip these files, can be 5x smaller.
+  - Turn C++ crashes into Lobster errors so they can be saved with a lot of context.
+  - For cycle objects, instead save object ids so a viewer can still find the original objects?
+
 - auto binding generated C++ headers from a Lobster decl
 
 - allow let inside if/guard as syntactic sugar

dev/src/lobster/vmdata.h

@@ -387,7 +387,8 @@ struct ToFlexBufferContext {
     string cycle_hit;
     flexbuffers::Builder::Value cycle_hit_value;
 
-    ToFlexBufferContext(VM &vm) : vm(vm) {}
+    ToFlexBufferContext(VM &vm, size_t initial_size, flexbuffers::BuilderFlag flags)
+        : vm(vm), builder(initial_size, flags) {}
 };
 
 struct Value {

dev/src/lobsterreader.cpp

@@ -395,7 +395,7 @@ nfr("flexbuffers_value_to_binary", "val,max_nesting,cycle_detection", "AI?B?", "
     "turns any reference value into a flexbuffer. max_nesting defaults to 100. "
     "cycle_detection is by default off (expensive)",
     [](StackPtr &, VM &vm, Value &val, Value &maxnest, Value &cycle_detect) {
-        ToFlexBufferContext fbc(vm);
+        ToFlexBufferContext fbc(vm, 1024, flexbuffers::BUILDER_FLAG_SHARE_KEYS);
         auto mn = maxnest.ival();
         if (mn > 0) fbc.max_depth = mn;
         fbc.cycle_detect = cycle_detect.True();

dev/src/vm.cpp

@@ -480,7 +480,7 @@ void VM::DumpStackTraceMemory(const string &err) {
     // We're going to be dumping as much as possible of the memory of the program along with
     // the stack trace. To this end we're using the FlexBuffers dumper which already can deal with
     // cycles etc, so it will output max 1 copy of each data structure.
-    ToFlexBufferContext fbc(*this);
+    ToFlexBufferContext fbc(*this, 1024 * 1024, flexbuffers::BUILDER_FLAG_SHARE_KEYS_AND_STRINGS);
     fbc.cycle_detect = true;
     fbc.max_depth = 64;
     fbc.ignore_unsupported_types = true;