Odd Behavior
Hello all, I ran into an error message in Guile, and I'm not sure how to track down the cause of it. I used a file called test.scm with the following contents: #!guile !# (define (codegen) #`(let ((message hello, world!\n)) (display message))) (define-syntax test (lambda (x) (syntax-case x () (_ (codegen) (test) Then I opened guile and did (load test.scm), and got this: ;;; compiling test.scm ;;; WARNING: compilation of test.scm failed: ;;; key wrong-type-arg, throw_args (#f Wrong type to apply: ~S (#f) (#f)) hello, world! As far as I can tell, this means that Guile tried to compile test.scm, failed, and then interpreted it correctly. Is that right? If so, is there a way to get more information about where the wrong-type-arg error was thrown? I'd also love to know any way to get more information about errors that happen during macroexpansion in general. I've been having quite a bit of trouble figuring out what is going wrong at different points in peg.scm, while I'm trying to convert it to syntax-case. Thanks, Noah
Re: Odd Behavior
Hello again, I tried finding the error by running compile-file, but I got the following Guile session: scheme@(guile-user) (compile-file test.scm) ice-9/boot-9.scm:119:21: Wrong type to apply: #f Entering a new prompt. Type `,bt' for a backtrace or `,q' to continue. scheme@(guile-user) ,bt Nothing to debug. boot-9.scm:119 is in the definition of custom-throw-handler, which is part of the implementation of catch. Noah On Mon, Jan 31, 2011 at 1:44 PM, Noah Lavine noah.b.lav...@gmail.com wrote: Hello all, I ran into an error message in Guile, and I'm not sure how to track down the cause of it. I used a file called test.scm with the following contents: #!guile !# (define (codegen) #`(let ((message hello, world!\n)) (display message))) (define-syntax test (lambda (x) (syntax-case x () (_ (codegen) (test) Then I opened guile and did (load test.scm), and got this: ;;; compiling test.scm ;;; WARNING: compilation of test.scm failed: ;;; key wrong-type-arg, throw_args (#f Wrong type to apply: ~S (#f) (#f)) hello, world! As far as I can tell, this means that Guile tried to compile test.scm, failed, and then interpreted it correctly. Is that right? If so, is there a way to get more information about where the wrong-type-arg error was thrown? I'd also love to know any way to get more information about errors that happen during macroexpansion in general. I've been having quite a bit of trouble figuring out what is going wrong at different points in peg.scm, while I'm trying to convert it to syntax-case. Thanks, Noah
Re: Odd Behavior
On Mon 31 Jan 2011 19:44, Noah Lavine noah.b.lav...@gmail.com writes: (define (codegen) #`(let ((message hello, world!\n)) (display message))) (define-syntax test (lambda (x) (syntax-case x () (_ (codegen) (test) Guile tried to compile test.scm, failed, and then interpreted it correctly. Is that right? Yep; as mentioned in the NEWS entry, ** Functions needed by macros at expand-time need to be present at expand-time. I'm sure you know that already, and your real question: is there a way to get more information about where the wrong-type-arg error was thrown? There are several ways this could be improved: * The exception should be about an unbound variable, not about applying #f. I'll see what I can do there. * The exception could be printed with an appropriate printer. See http://thread.gmane.org/gmane.lisp.guile.devel/11066/focus=11158. * You should see the source location of the error and the containing forms. Probably that thread is the best bet for making a start at this. Regards, Andy -- http://wingolog.org/
Re: Odd Behavior
On Mon 31 Jan 2011 19:44, Noah Lavine noah.b.lav...@gmail.com writes: ;;; compiling test.scm ;;; WARNING: compilation of test.scm failed: ;;; key wrong-type-arg, throw_args (#f Wrong type to apply: ~S (#f) (#f)) hello, world! Now it does: scheme@(guile-user) (load /tmp/test.scm) ;;; note: autocompilation is enabled, set GUILE_AUTO_COMPILE=0 ;;; or pass the --no-autocompile argument to disable. ;;; compiling /tmp/test.scm ;;; WARNING: compilation of /tmp/test.scm failed: ;;; key unbound-variable, throw_args (#f Unbound variable: ~S (codegen) #f) hello, world! Still ugly, but better. Thanks for the example. A -- http://wingolog.org/
Re: Odd Behavior
Wow, great! On Mon, Jan 31, 2011 at 3:12 PM, Andy Wingo wi...@pobox.com wrote: On Mon 31 Jan 2011 19:44, Noah Lavine noah.b.lav...@gmail.com writes: ;;; compiling test.scm ;;; WARNING: compilation of test.scm failed: ;;; key wrong-type-arg, throw_args (#f Wrong type to apply: ~S (#f) (#f)) hello, world! Now it does: scheme@(guile-user) (load /tmp/test.scm) ;;; note: autocompilation is enabled, set GUILE_AUTO_COMPILE=0 ;;; or pass the --no-autocompile argument to disable. ;;; compiling /tmp/test.scm ;;; WARNING: compilation of /tmp/test.scm failed: ;;; key unbound-variable, throw_args (#f Unbound variable: ~S (codegen) #f) hello, world! Still ugly, but better. Thanks for the example. A -- http://wingolog.org/
