Module Core.Debug

Utilities for printing debug messages.

val eprint : Base.String.t -> Base.Unit.t @@ portable

eprint message prints to stderr message, followed by a newline and flush. This is the same as prerr_endline.

val eprints : Base.String.t -> 'a -> ('a -> Sexp.t) -> Base.Unit.t @@ portable

eprints message a sexp_of_a prints to stderr message and a as a sexp, followed by a newline and flush.

val eprint_s : Sexp.t -> Base.Unit.t @@ portable

eprint_s sexp prints sexp to stderr, followed by a newline and a flush.

val eprintf : ('r, Base.Unit.t, Base.String.t, Base.Unit.t) format4 -> 'r @@ portable

eprintf message arg1 ... argn prints to stderr message, with sprintf-style format characters instantiated, followed by a newline and flush.

module Make () : sig ... end

Debug.Make produces a debug function used to wrap a function to display arguments before calling and display results after returning. Intended usage is:

val am : Source_code_position.t -> Base.Unit.t @@ portable

am, ams, and amf output a source code position and backtrace to stderr. amf accepts a printf-style format string. ams accepts a message, value, and sexp converter for that value. Typical usage looks like:

    ...;
  Debug.am [%here];
    ...;
    Debug.amf [%here] "hello (%s, %s)" (X.to_string x) (Y.to_string y);
    ...;
    Debug.ams [%here] "hello" (x, y) [%sexp_of: X.t * Y.t];
    ...;

The am* functions output source code positions in the standard format "FILE:LINE:COL", which means that one can use a tool like emacs grep-mode on a buffer containing debug messages to step through one's code by stepping through the messages.

val ams : Source_code_position.t -> Base.String.t -> 'a -> ('a -> Sexp.t) -> Base.Unit.t @@ portable
val amf : Source_code_position.t -> ('r, Base.Unit.t, Base.String.t, Base.Unit.t) format4 -> 'r @@ portable
val should_print_backtrace : Base.Bool.t Atomic.t @@ portable

should_print_backtrace governs whether the am* functions print a backtrace.