Dear Richard, Thanks for your email. I indeed use native code as I need the speed. My program is 3500 lines, and includes multi-dimensional arrays, to putting try's everywhere by hand is out of the question. I would then have to write a metaprogram that adds such try commands to an existing OCaml program and outputs a longer program with the try's with the asserts. If possible I would like to postpone that and try your other option. Due to this crashing business I go on a business trip to Asia without any ready simulation results for one week. > * Use bytecode, and before running the program set the environment > variable OCAMLRUNPARAM=b which will print a stack trace. If I would use this week of the trip to try this suggestion you made, how will the stack trace give me the line number? Best regards, Andries ------------------------------------------------------------------------ Dr. Ir. Andries P. Hekstra Philips Research High Tech Campus 27 (WL-1-4.15) 5656 AG Eindhoven Tel./Fax/Secr. +31 40 27 42048/42566/44051 * Good open source break software for computer users : http://www.workrave.org Richard Jones 06-03-2006 12:14 To Andries Hekstra/EHV/RESEARCH/PHILIPS@PHILIPS cc caml-list@yquem.inria.fr Subject Re: [Caml-list] Line number for index out of bounds Classification On Mon, Mar 06, 2006 at 11:44:31AM +0100, Andries Hekstra wrote: > Invalid_argument("index out of bounds") [...] > Of course, I am very curious in which line number of the program this > exception occurs. > Is there any way to get hold of this line number? This is a real problem with OCaml - it's impossible to get stack traces of where an exception happens with native code. I'm assuming you're using native code. I commonly have cases where a program dies with "exception: Not_found" because I forgot to enclose some List.find with an appropriate try ... with clause, or made some wrong assumption. Tracking these down is time-consuming. Possible workarounds: * Use bytecode, and before running the program set the environment variable OCAMLRUNPARAM=b which will print a stack trace. * Surround every possible array index with a try ... with expression like this: try (* code which accesses the array *) with Invalid_argument "index out of bounds" -> assert false The "assert false" will print the line and character number of the assertion. * Hack ocamlopt to be able to print exceptions properly :-) Rich. -- Richard Jones, CTO Merjis Ltd. Merjis - web marketing and technology - http://merjis.com Team Notepad - intranets and extranets for business - http://team-notepad.com