[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: debugging and lambda variables
The current set of debugging tools is weak, and sometimes the best
thing to do IS to insert print-statements. While the "inspector"
(crawl) is fairly powerful, the user interface to it is also weak.
But designing and implementing a good debugging system is a difficult
task, and in the large scheme of things, has been assigned a fairly
low priority, and justifiably so. Would you really ask the implementors
to postpone work on, say, garbage collection to launch into a large
programming environments project? It's simply too soon.
On the other hand, there are people working on T tools, at least here
at CSI. Just slightly more helpful than TRACE are BREAK and WATCH,
which were announced in T-USERS or some comparable bboard quite a while
ago. We're also working on inspector-like programs, and somewhere
on our wish-list is the use of graphics to aid in this process.
(Example: the stack is all written out vertically. You put the cursor
next to one frame, hit some command key, and a "subwindow" opens up,
showing you the details of that frame. Etc., etc.) Many debugging
systems, not just T's, are suited to a hardcopy technology, with
"command lines" and printed displays of information. Bringing them
into the bitmapped age is difficult. Consider the complexity of some
of the fancy tools such as the Programmer's Assistant from Xerox, and
you'll know why this isn't an easy task.