Re: [Chicken-users] Line numbers in error output?

[Peter Bex]

On Sat, Jul 06, 2013 at 02:16:16PM -0700, J Altfas wrote:
> Error: (string-append) bad argument type - not a string: ()
> 
>         Call history:
> 
>         httm.scm:42: indent-sz
>         httm.scm:42: make-string
>         httm.scm:87: ##sys#print
>         httm.scm:87: ##sys#print
>         httm.scm:87: ##sys#print
>         httm.scm:87: ##sys#write-char-0
>         httm.scm:90: html-eol
>         httm.scm:87: ##sys#print
>         httm.scm:87: get-output-string
>         httm.scm:83: tloop
>         httm.scm:94: htmatch
>         httm.scm:39: ->string
>         httm.scm:39: common#strcat
>         httm.scm:39: attrloop
>         httm.scm:39: ->string
>         httm.scm:39: common#strcat              <--
> 
> True enough, string-append chokes when feeding it a non-string, but the issue 
> is the trace showing the series of calls bouncing around in a loop in httm, 
> whereas the error's instigator (where the not-a-string was wrongly supplied) 
> was maybe several frames up in the series of procedural calls.

That happens occasionally, and is annoying.  Perhaps this helps: you can
start any CHICKEN program (including a script via command line arguments
to csi) by invoking it with -:? and it'll show you how to set various
run-time options.  One of them is -:aX which sets the number of entries
to be kept in the call chain buffer to the value of X.  By increasing it
you may be able to view the error's root cause more easily.

> Which leads to the idea that what Chicken really needs is a full-fledged 
> debugger.  I realize it's been a subject often discussed, yet still seems to 
> be an elusive goal.

Well, nobody's stopping you from building one ;)

Cheers,
Peter
-- 
http://www.more-magic.net