Printexc.to_string e returns a string representation of
the exception e.
valprint : ('a -> 'b) -> 'a -> 'b
Printexc.print fn x applies fn to x and returns the result.
If the evaluation of fn x raises any exception, the
name of the exception is printed on standard error output,
and the exception is raised again.
The typical use is to catch and report exceptions that
escape a function application.
valcatch : ('a -> 'b) -> 'a -> 'b
Printexc.catch fn x is similar to Printexc.print, but
aborts the program with exit code 2 after printing the
uncaught exception. This function is deprecated: the runtime
system is now able to print uncaught exceptions as precisely
as Printexc.catch does. Moreover, calling Printexc.catch
makes it harder to track the location of the exception
using the debugger or the stack backtrace facility.
So, do not use Printexc.catch in new code.