Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.sys.acorn.programmer > #613
| From | Martin <News03@avisoft.f9.co.uk> |
|---|---|
| Subject | Re: Can anyone spot why this menu doesn't change anything please. |
| Newsgroups | comp.sys.acorn.programmer |
| Date | 2011-08-14 10:54 +0100 |
| Message-ID | <5202921b82News03@avisoft.f9.co.uk> (permalink) |
| References | <b23406a1-d5de-42a9-8904-ae0fcdc5b8ab@s7g2000yqk.googlegroups.com> |
| Organization | None |
If you change the code in Glue to add just three debugging statements ...
REM Toggle a bit in a given bitmask.
DEFPROCdev_togglebit(pos%,RETURN mask%)
*Report "Toggle" ~mask% pos%
IF FNdev_tstbit(pos%,mask%) THEN
mask%=mask% OR (0<<pos%)
*Report "True " ~mask%
ELSE
mask%=mask% OR (1<<pos%)
*Report "False" ~mask%
ENDIF
ENDPROC
you will immediately see that all is not well, as mask% never changes.
A moments contemplation and you will realise 'mask% OR (0<<pos%)' does
NOT set a bit off!
An exellent example of why you need to see what IS happening, rather than
what you expect to happen.
<plug type=shameless>
Use Reporter!
Tip: If you run your single-tasking program in a Task Window, you can see
the Reporter information as it happens. And the source.
</plug>
Yes, you can also just use PRINT ~mask%, but it can mess up your output,
and is not so easy to identify to remove after debugging.
Martin
--
Martin Avison
Note that unfortunately this email address will become invalid
without notice if (when) any spam is received.
Back to comp.sys.acorn.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-13 07:01 -0700
Re: Can anyone spot why this menu doesn't change anything please. Martin <News03@avisoft.f9.co.uk> - 2011-08-13 16:18 +0100
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-13 09:47 -0700
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-13 11:41 -0700
Re: Can anyone spot why this menu doesn't change anything please. Martin <News03@avisoft.f9.co.uk> - 2011-08-13 23:35 +0100
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-13 15:45 -0700
Re: Can anyone spot why this menu doesn't change anything please. Martin <News03@avisoft.f9.co.uk> - 2011-08-14 10:54 +0100
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-14 04:27 -0700
Re: Can anyone spot why this menu doesn't change anything please. Martin <News03@avisoft.f9.co.uk> - 2011-08-14 12:43 +0100
Re: Can anyone spot why this menu doesn't change anything please. Martin Bazley <martin.bazley@blueyonder.co.uk> - 2011-08-14 14:18 +0100
Re: Can anyone spot why this menu doesn't change anything please. Martin <News03@avisoft.f9.co.uk> - 2011-08-14 15:24 +0100
Re: Can anyone spot why this menu doesn't change anything please. "Barry Allen (news)" <evanallen@onetel.net.uk.invalid> - 2011-08-14 15:48 +0100
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-14 08:46 -0700
Re: Can anyone spot why this menu doesn't change anything please. Alan Wrigley <spamhater@keepyourfilthyspamtoyourself.co.uk> - 2011-08-14 18:36 +0100
Re: Can anyone spot why this menu doesn't change anything please. Gazza <usenet@garethlock.com> - 2011-08-21 02:50 -0700
Re: Can anyone spot why this menu doesn't change anything please. Martin Bazley <martin.bazley@blueyonder.co.uk> - 2011-08-13 18:00 +0100
csiph-web