Added more notes for error handling

TODO

@@ -14,7 +14,25 @@ Working TODO list:
 
    - improved error handling:
      - code traces
+       could pass filename and define name (if applicable) to c-compile-exp,
+       and record it for each lambda. could then add code to each lambda to 
+       write that info to a circular buffer when the function is called.
+       that would enable a primitive stack trace to be maintained at runtime.
+
+       ideally use an array of (char *) and a pointer incremented like (i = (i + 1) % size)
+       to treat it as a circular buffer
+
+       as a starting point, could encode lambda name and filename and get the
+       circular buffer and runtime reporting working. then come back and add
+       Scheme function names.
+
      - type checking
+       ideally want to do this in a way that minimized performance impacts.
+       will probaby require extensive checks within apply() though, since that
+       all happens at runtime.
+
+     - error checking
+       need errors for things such as file not existing, to bullet-proof the runtime
 
      without these, it will be impossible (or at least time-consuming) to debug issues going forward