Module Batteries.Printexc

module Printexc: BatPrintexc

val pass : ('a -> 'b) -> 'a -> 'b
Printexc.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 -> '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.
val to_string : exn -> string
Printexc.to_string e returns a string representation of the exception e.
val print_backtrace : 'a BatInnerIO.output -> unit
print_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.
Since 1.4.0
val get_backtrace : unit -> string
Printexc.get_backtrace () returns a string containing the same exception backtrace that Printexc.print_backtrace would print.
val record_backtrace : bool -> unit
Printexc.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 -> bool
Printexc.backtrace_status() returns true if exception backtraces are currently recorded, false if not.
val register_printer : (exn -> string option) -> unit
Printexc.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 -> unit
Print an exception. The stdlib print function is now named !pass.

Raw backtraces

type raw_backtrace = Printexc.raw_backtrace 

The abstract type backtrace stores exception backtraces in a low-level format, instead of directly exposing them as string as the get_backtrace() function does.

This allows to pay the performance overhead of representation conversion and formatting only at printing time, which is useful if you want to record more backtrace than you actually print.

val get_raw_backtrace : unit -> raw_backtrace
val print_raw_backtrace : Pervasives.out_channel -> raw_backtrace -> unit
val raw_backtrace_to_string : raw_backtrace -> string

Current call stack

val get_callstack : int -> raw_backtrace

Printexc.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.)