func newExceptionValue(s *C.mrb_state) *Exception {
if s.exc == nil {
panic("exception value init without exception")
}
arenaIndex := C.mrb_gc_arena_save(s)
defer C.mrb_gc_arena_restore(s, C.int(arenaIndex))
// Convert the RObject* to an mrb_value
value := C.mrb_obj_value(unsafe.Pointer(s.exc))
// Retrieve and convert backtrace to []string (avoiding reflection in Decode)
var backtrace []string
mrbBacktrace := newValue(s, C.mrb_exc_backtrace(s, value)).Array()
for i := 0; i < mrbBacktrace.Len(); i++ {
ln, _ := mrbBacktrace.Get(i)
backtrace = append(backtrace, ln.String())
}
// Extract file + line from first backtrace line
file := "Unknown"
line := 0
if len(backtrace) > 0 {
fileAndLine := strings.Split(backtrace[0], ":")
if len(fileAndLine) >= 2 {
file = fileAndLine[0]
line, _ = strconv.Atoi(fileAndLine[1])
}
}
result := newValue(s, value)
return &Exception{
MrbValue: result,
Message: result.String(),
File: file,
Line: line,
Backtrace: backtrace,
}
}
// Restores the arena index so the objects between the save and this point
// can be garbage collected in the future.
//
// See ArenaSave for more documentation.
func (m *Mrb) ArenaRestore(idx ArenaIndex) {
C.mrb_gc_arena_restore(m.state, C.int(idx))
}