Hello, I'm currently coding a game using scheme as a scripting language. The main program is a C program which first exports C functions to scheme and then calls a scheme script. This scheme script is responsible for all game logic, interaction, control, whatever, and the C functions are low-level stuff (such as OpenGL graphics, simple core algorithms which needs to run as fast as possible, and so on).
Of course I'm using Guile for this 8-) I'm pretty happy with it for now, I'm just discovering Scheme (previously experienced with Perl, Python and Lua) and it's performing pretty well. Most of all it does what I need. But... (there's always a "but...") I find it hard to debug. I assume I'm not using it the correct way, or that I missed something. Here's my problem: when there's an error in scheme code, Guile terminates my program immediately and gives me an error message which is often not precise enough for proper debugging. Here's an example, with code excerpts (full code on http://ufoot.hd.free.fr/snapshot/pub/ , project liquidwar6). When I run scheme code from C code, placing on purpose an error in the scheme code (I add a "(car ())" line in some random place) and call it with: ---------8<------------------------------------------------ scm_c_primitive_load (script); ---------8<------------------------------------------------ with script a char * pointing to "src/script/liquidwar6.scm" I get the following output: ---------8<------------------------------------------------ liquidwar6: registering C functions for Guile liquidwar6: loading "src/script/liquidwar6.scm" ERROR: missing or extra expression ---------8<------------------------------------------------ The lines with liquidwar6: are output from my C program, using C log functions. The line with "ERROR" is an output from Guile, which terminates the program. As a side note the fact that it terminates the program is a bit annoying, since I would like to "trap" this message. Indeed a windows user will never read console output, and if I want proper bug reports from players, I'd better display this message in a popup. Then this message is a little "light" for proper debugging. When I'll have 10000 lines of scheme code, it will be impossible to track bugs without informations like line number for instance. Point is if I call "load" are "primitive-load" from the Guile interpreter I get much more information: ---------8<------------------------------------------------ guile> (load "src/script/liquidwar6.scm") src/script/loop.scm:20:1: While evaluating arguments to car in expression (car ()): src/script/loop.scm:20:1: missing or extra expression ABORT: (misc-error) Type "(backtrace)" to get more information or "(debug)" to enter the debugger. guile> ---------8<------------------------------------------------ ---------8<------------------------------------------------ guile> (primitive-load "src/script/liquidwar6.scm") src/script/loop.scm:20:1: While evaluating arguments to car in expression (car ()): src/script/loop.scm:20:1: missing or extra expression ABORT: (misc-error) guile> ---------8<------------------------------------------------ This would be very fine: filename, line number, code excerpt, these are the very informations I need. Anyone would have an idea on how to: 1) trap, redirecet or place a hook on the Guile "error handler" (if such a handler exists?) and get these errors in C, and then decide what to do with it. 2) actually get precise error informations (file, line, source, error description) the way the interactive Guile interpreter does. I read the Guile manual, but: http://www.gnu.org/software/guile/docs/guile-ref/Debugging-Features.html and: http://www.gnu.org/software/guile/docs/guile-ref/Hooks.html did not solve my problem. At least I couldn't find a solution reading them. Any clue? Thanks in advance, Christian. -- Christian Mauduit <[EMAIL PROTECTED]> __/\__ ___ \~/ ~/(`_ \ ___ http://www.ufoot.org/ /_o _\ \ \_/ _ \_ http://www.ufoot.org/gnupg.pub \/ \___/ \__) _______________________________________________ Guile-user mailing list Guile-user@gnu.org http://lists.gnu.org/mailman/listinfo/guile-user
