Re: GUI for Hat

Hi Pete,

great to see another person working on a GUI for Hat.

I'd be a bit more careful with the problem description. Many of the 
tools are linked together, you can call one from the other. This is 
actually a very modular approach. Second, it is not immediate that a GUI 
makes a tool easier to learn or to use. The idea of a tool still needs 
to be understood and in how far is a GUI easier to use? Nonetheless, 
there is certainly the problem that the current text tools don't work 
under Windows and a GUI is more attractive for many users. And I'm sure 
mouse input and graphics can make a tool easier to use, but that needs 
more thought.

You list a lot of tools; several of which seem to be new. I'd 
concentrate on one or very few. Getting one that works really well is 
better than several half-working. Still, as Neil said, first providing a 
GUI for a simple existing one may be good practice to start going.

Much success,
ciao,
Olaf

Peter Nuttall wrote:

>Hello all, 
>
>I'm doing my dissertation on writing a GUI for hat, and Neil Mitchell
>suggested I send a mail saying what i was planning to see if you guys
>had any good ideas or comments. This is the proposal:
>
>The problem
>
>Hat provides a easy way to generate a trace, and various tools have
>been developed to examine the traces produced by it. However, these
>tools have two main flaws: They are hard to learn and use and they are
>not linked together. Ideally we would like hat to be as easy to use as
>possible. This way it can both be used to debug real programs by Haskell
>programmers, but can be used as a teaching tool for beginners, so they
>can see how lazy evaluation works and find simple bugs when they write
>their first programs.
>
>The solution
>
>Write a graphical user interface to Hat. A clickable GUI will be easier to
>use than a ncurses GUI, and will seem easier to use. The
>GUI will provide the same functionality as the hat tools do already,
>but it will be easier to use. This will be done by separating out the
>current user interface from the functionality as much as possible, then
>making the functionality into a library. As part of this, I will try and
>upgrade the tools to use the new tracing library written by Tom Shackell.
>
>The GUI's will be implemented in GTK2HS . It will consist of a Window
>with tabs for each tool. Neil Mitchell has already constructed a GUI,
>and I plan to use this as a starting point.
>
>The tools that will be usable though the GUI will be:
>
>Search
>
>This will let the user search though all the functions called, and see
>that function.s inputs and output. The UI will be based on that of JuK,
>with searching using haskell.s pattern matching syntax.
>
>Monad
>
>A step over debugger for do blocks. This will be similar to normal
>debuggers
>
>Stack.
>
>When loading a a trace that has terminated with an error, the GUI
>will show a listing of the last functions called and their inputs and
>outputs. It will collapse any loops.
>
>Cover
>
>It will use hs-colour to try and show which functions are being used
>for a set of inputs. If the new tracing library is used, and it supports
>taking the union of traces, this will be used to show coverage from lots
>of traces. This can be tied into quickcheck.
>
>
>Ethereal bit.
>
>Ethereal is a tool for examining network traffic, and my plan is to
>. borrow from it's "follow TCP stream" feature, which shows you all the
>traffic in a stream, and lets you see messages and replies. It will
>show text moving in and out of handles, and display the logical time
>between messages. 
>
>Display bit.
>
>This will allow the user to see how redexes happen and allow the use to
>see laziness in action. This will be based on hat-amin. It is dependent
>on writing a good graph drawing function.
>
>algorithmic
>
>This will be a normal algorithmic debugger,  though I haven.t thought
>of how it will work in a GUI.
>
>Any suggestions, comments?
>
>Pete
>
>
>
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>  
>