Good morrow!

Why not to define a numeric types representing "procents" or "promiles".
These would be useful for beginners and in some applications like Tk.
While creating a widget one could set the dimentions either in percents
or in pixels. The method would treat numbers as absolute coordinates and
percents as relatives to the parent's size. 

Unfortuantely, the "%" operator is used a lot as remainder operator and
for conditional formatting :(

And what about types for meters, miles, feets etc. Automatic convertion
while assignment whould be useful. But language should support constants
of that type. Maybe use letters after digits: 10mm, 15cm, 5,8miles,
4.45kg, 35%.

Raising exceptions on trying to add some kilograms to some miles would
protect user of a lot of algorithmical mistakes.

Aleksei Guzev