Module Printexc.Slot

module Slot: sig .. end

type t = Printexc.backtrace_slot 
val is_raise : t -> bool
is_raise slot is true when slot refers to a raising point in the code, and false when it comes from a simple function call.
val is_inline : t -> bool
is_inline slot is true when slot refers to a call that got inlined by the compiler, and false when it comes from any other context.
val location : t -> Printexc.location option
location slot returns the location information of the slot, if available, and None otherwise.

Some possible reasons for failing to return a location are as follow:

val format : int -> t -> string option
format pos slot returns the string representation of slot as raw_backtrace_to_string would format it, assuming it is the pos-th element of the backtrace: the 0-th element is pretty-printed differently than the others.

Whole-backtrace printing functions also skip some uninformative slots; in that case, format pos slot returns None.