module Printexc: BatPrintexcval pass : ('a -> 'b) -> 'a -> 'bPrintexc.pass 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. This function is a
renamed version of Printexc.print from stdlib.val catch : ('a -> 'b) -> 'a -> 'bPrintexc.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.val to_string : exn -> stringPrintexc.to_string e returns a string representation of the
exception e.val print_backtrace : 'a BatInnerIO.output -> unitprint_backtrace oc Prints the an exception backtrace on the
output channel oc. The backtrace lists the program locations
where the most-recently raised exception was raised and where it
was propagated through function calls.val get_backtrace : unit -> stringPrintexc.get_backtrace () returns a string containing the same
exception backtrace that Printexc.print_backtrace would print.val record_backtrace : bool -> unitPrintexc.record_backtrace b turns recording of exception
backtraces on (if b = true) or off (if b = false). Initially,
backtraces are not recorded, unless the b flag is given to the
program through the OCAMLRUNPARAM variable.val backtrace_status : unit -> boolPrintexc.backtrace_status() returns true if exception
backtraces are currently recorded, false if not.val register_printer : (exn -> string option) -> unitPrintexc.register_printer fn registers fn as an exception
printer. The printer should return None or raise an exception
if it does not know how to convert the passed exception, and Some
s with s the resulting string if it can convert the passed
exception. Exceptions raised by the printer are ignored.
When converting an exception into a string, the printers will be invoked
in the reverse order of their registrations, until a printer returns
a Some s value (if no such printer exists, the runtime will use a
generic printer).
val print : 'a BatInnerIO.output -> exn -> unitprint function is now named !pass.typeraw_backtrace =Printexc.raw_backtrace
raw_backtrace stores a backtrace in
a low-level format, instead of directly exposing them as string as
the get_backtrace() function does.
This allows delaying the formatting of backtraces to when they are actually printed, which may be useful if you record more backtraces than you print.
Raw backtraces cannot be marshalled. If you need marshalling, you
should use the array returned by the backtrace_slots function of
the next section.
Since 2.2.0 and OCaml 4.01.0
val get_raw_backtrace : unit -> raw_backtracePrintexc.get_raw_backtrace () returns the same exception
backtrace that Printexc.print_backtrace would print, but in
a raw format.val print_raw_backtrace : Pervasives.out_channel -> raw_backtrace -> unitPrintexc.print_backtrace uses.val raw_backtrace_to_string : raw_backtrace -> stringPrintexc.get_backtrace uses.val get_callstack : int -> raw_backtracePrintexc.get_callstack n returns a description of the top of the
call stack on the current program point (for the current thread),
with at most n entries. (Note: this function is not related to
exceptions at all, despite being part of the Printexc module.)val set_uncaught_exception_handler : (exn -> raw_backtrace -> unit) -> unitPrintexc.set_uncaught_exception_handler fn registers fn as the handler
for uncaught exceptions. The default handler prints the exception and
backtrace on standard error output.
Note that when fn is called all the functions registered with
Pervasives.at_exit have already been called. Because of this you must
make sure any output channel fn writes on is flushed.
If fn raises an exception, it is ignored.
Since 2.3.0 and OCaml 4.02.0
Those function allow to traverse the slots of a raw backtrace,
extract information from them in a programmer-friendly format.
typebacktrace_slot =Printexc.backtrace_slot
backtrace_slot represents a single slot of
a backtrace.val backtrace_slots : raw_backtrace -> backtrace_slot array optionNone if none of them
contain useful information.
In the return array, the slot at index 0 corresponds to the most
recent function call, raise, or primitive get_backtrace call in
the trace.
Some possible reasons for returning None are as follow:
-g)ocamlc -g)typelocation =Printexc.location= {
|
filename : |
|
line_number : |
|
start_char : |
|
end_char : |
start_char
and end_char are positions relative to the beginning of the
line.module Slot:sig..end
typeraw_backtrace_slot =Printexc.raw_backtrace_slot
Elements of this type can still be compared and hashed: when two
elements are equal, then they represent the same source location
(the converse is not necessarily true in presence of inlining,
for example).
val raw_backtrace_length : raw_backtrace -> intraw_backtrace_length bckt returns the number of slots in the
backtrace bckt.val get_raw_backtrace_slot : raw_backtrace -> int -> raw_backtrace_slotget_slot bckt pos returns the slot in position pos in the
backtrace bckt.val convert_raw_backtrace_slot : raw_backtrace_slot -> backtrace_slotbacktrace_slot from a low-level
raw_backtrace_slot.val exn_slot_id : exn -> intPrintexc.exn_slot_id returns an integer which uniquely identifies
the constructor used to create the exception value exn
(in the current runtime).val exn_slot_name : exn -> stringPrintexc.exn_slot_id exn returns the internal name of the constructor
used to create the exception value exn.