Re: galculator should be included in Gnome [OT rant]

[Owen Taylor <otaylor redhat com>]

Drifting off topic here - (note that I haven't looked at gcalctool)

While the concept of copying a simple 4 function calculator may have
a bit of merit - people are familiar with that - copying a physical
calculator really is a entirely broken way of presenting a interface
for interactive calculations.

Problems with it:

 - Retyping numbers; if a number occurs multiple times in 
   a calculation you have to retype each time, or think ahead
   and put them in a memory first
 - Lack of symbolic names for variables
 - No ability to correct mistakes
 - Is not obvious how to navigate with the keyboard
 - Is clumsy to keyboard navigate
 - Typically has cryptic abbreviations for the key names
 - Doesn't take advantage of the display area available
   on a computer

I could go on and on. This problem could use a lot of rethinking.

I'd think it might be better to start off with a command line
calculation tool (I actually typically use python or gdb when
I need to calculate stuff) and think how you can improve it
with a GUI. Random ideas:

 - Nice completion on functions and variables. Type s, and
   dropdown pops down with sin(), etc, in it.

 - Every number entered and result gets tagged with some sort
   of annotation that can be used (think gdb's $4) or DND'ed
   to a variable bar where a name can be assigned to it.

 - If you go back and edit an earlier formula in the buffer,
   the change takes effect and propagates.

There are a lot of examples of interfaces that could serve as
prior art - bc, Mathematica, shell-mode in emacs, etc, etc. Many of
them admittedly, are experts-only or simply hideous.

But I think if one sat down and plan out what you want people to
be able to do with tool tool - whether it's summing up lists of
numbers or plugging in numbers in their Physics homework - and
what is *not* in scope for the tool (it shouldn't try to replace
gnumeric or mathematic), you should be able to do *so* much better
than trying to reproduce the details of a physical calculator,
whether it is Casio, TI, Sharp, or HP. 

Regards,
                                             Owen