Let's talk about debuggers!

[Terry Reedy]

On 10/25/2017 12:12 PM, Thomas Jollans wrote:
> On 2017-10-25 15:57, Rustom Mody wrote:
>>
>> pdb inside emacs works (to a fashion)
>> And it shows the arrow for current line so its at least quasi-gui
>>
>> I believe idle too is much more usable than a few years earlier
> 
> I haven't used IDLE in years (if ever), partly because Tkinter is so
> incredibly ugly, and feels so out-of-place on a modern PC (maybe it's
> tolerable on Windows, I wouldn't know).

On Windows, it uses native widgets when possible, so the look and feel 
of IDLE's editor is the same as some other apps, such as Notepad++.  We 
are in the process of switching to the ttk widget set, which improve the 
look on Linux and even more so on Macs.  The settings dialog was redone, 
in part, for 3.6.3 and 3.7.  Which version are you using?

> In any case I just tried it out and good lord that's terrible.

The debugger UI has not gotten its badly needed makeover yet; there is a 
issue and patch to do so.

> You can
> set breakpoints in the editor (good), it shows locals (excellent), but
> it doesn't show you what line you're at when stepping through (seriously?).

Seriously, you either did not look, or you have a broken IDLE 
installation, or you ran into a severe bug I would like to know about. 
Rather than never, the next line is shown 2 or 3 times.

1.The module, line number, and code of the next line is shown 
immediately below the header of buttons and checkboxes.

2. The box below shows the complete stack of Python lines in the process 
of being run, including (again) the one that will be executed next.  For 
each, it shows the module, line number, and text of the line.

Bug: code and line number are reversed on the last line, which is the 
repeat of the next line.  Enhancement: make list more readable with 
module, number, and code in neat columns.  The window will have to be 
much wider, or each line split as in tracebacks, to do this.

3. If one checks the '[X] source' box at the top, the 'next' line is 
highlighted in an IDLE editor window.  This is currently not checked by 
default because the debugger would currently open *every* file stepped 
into.  When opening new windows is made optional, source will be checked 
by default.

In summary, I think debugger should rate at least 'good' rather than 
'fail' when it comes to showing you the next line.

> I'll go back to not even touching IDLE with a ten-foot pole now.

Do as you want, but please report accurately.  There are bugs around the 
debugger, but not, that I know of, the one you claim.
-- 
Terry Jan Reedy