The stack function will show the current function
calling stack, expressed as a list of functions that
the interpreter is currently evaluating. To trace the execution path of
parts of a program it is useful to print out the code as it is evaluated.
The trace and notrace functions
act as delimiters to areas when tracing should occur. The tracing
information is delivered to standard output.
The following table of predefined global variables provides additional information useful for debugging:
| Global Variable | Description |
|---|---|
_error_stack_ | The stack at the time the last error occured. |
_unwind_stack_ | The stack at the time that an error was discovered. |
_last_error_ | A string containing the last error. |