Utilities for printing debug messages.
eprint message
prints to stderr message
, followed by a newline and flush. This is
the same as prerr_endline
.
eprints message a sexp_of_a
prints to stderr message
and a
as a sexp, followed
by a newline and flush.
eprint_s sexp
prints sexp
to stderr, followed by a newline and a flush.
eprintf message arg1 ... argn
prints to stderr message
, with sprintf-style format
characters instantiated, followed by a newline and flush.
Debug.Make
produces a debug
function used to wrap a function to display arguments
before calling and display results after returning.
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.