Printing values in CINT and some thoughts

From: Damir Buskulic (buskulic@lapp.in2p3.fr)
Date: Wed Jun 24 1998 - 12:55:58 MEST


Hi everybody,

When a newbie ROOT user wants to see how ROOT works, he does things like
:

root [0] TText * t="fgftrjhjh"
root [1] t
(class TText*)0x1407b98c0
root [2] TString * t1="fgftrjhjh"
root [3] t1
(class TString*)0x1407b98c0

Usually, people expect a little bit more info., for example the content
of a string. If they do

root [17] TString j="bbbbbvbbbb"
root [18] j
(class TString)5376838504

There is no way except j.Data() to print the content. that's very
un-intuitive. Should we think more about intuitiveness ?
Is there any general method (object.Info() for example) that could be
called each time the user specifies just the name of the object ?.
I think it's important for these new users to feel comfortable very
quickly, if they know C/C++, and if we don't want them to be discouraged
and feel like "this is clearly not yet a finished product. Should we use
it ?"
(unfortunately, I heard already that kind of remarks). We know that ROOT
has still some road ahead but this kind of remarks leaves me a little
bit uncomfortable, even when I know and plea for the power of ROOT.

On a side note, when someone doesn't specify the type of a variable, for
example

root [30] a="gfgfg"
Warning: Undeclared data member a FILE:/tmp/ebaaaCfba LINE:1
(char* 0x140830640)"gfgfg"
*** Interpreter error recovered ***

The first reflex of a new user is to try to redeclare his variable :
root [31] TString a="gfgfg"

and of course the result is :

Error: a already declared as different type. ~TString() called
 FILE:/tmp/fbaaaCfba LINE:1
*** Interpreter error recovered ***

And I don't know how to remove the variable a... So I have to declare
another var. with another name...

I know this is logical but it make people feel like ROOT is very
difficult to be acustomed to, at least at the beginning. And this is not
good marketing...

Well, did anybody tried to use ROOT in a teaching environnement ?
Students are the best test for intuitiveness. They don't forgive you
anything...

Sorry for this long message, I think this could be a rather important
issue. Anyway, I remain very confidant...

Cheers 

Damir
-- 
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| Damir Buskulic                  | Universite de Savoie/LAPP       |
|                                 | Chemin de Bellevue, B.P. 110    |
| Tel : +33 (0)450091600          | F-74941 Annecy-le-Vieux Cedex   |
| e-mail: buskulic@lapp.in2p3.fr  | FRANCE                          |
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