(doc) document how TaurusValueLineEdit parses quantities

[jairomoldes]

It looks like white spaces are interpreted as multiplication sign when editing the value.

To reproduce simply run the default sample code:
(e.g.) python ~/workspace/taurus/lib/taurus/qt/qtgui/input/tauruslineedit.py
and type "2 3" (withouth the quotes) and then enter. You will see that the write value of "sys/tg_test/1/double_scalar" has been change to 6 (2*3)

[cpascual]

Confirmed. It comes from the parsing done by pint:

In [1]: from pint import UnitRegistry

In [2]: UR = UnitRegistry()

In [3]: UR.parse_expression('2 3')
Out[3]: 6

In [4]: UR.parse_expression('2 3 m 4 s**-1')
Out[4]: <Quantity(24.0, 'meter / second')>

It seems to me that this is considered a feature, not a bug in pint (see hgrecco/pint#226 and hgrecco/pint#34).
I personally prefer not to implement/maintain/document a custom parser , and so I propose to close this as "wontfix"

[jairomoldes]

From my point of view this is confusing, but if you all agree that it is acceptable I will not oppose to close it as "wontfix"

[cpascual]

I see your point, but I think that the confusion would be mitigated if we prominently document that the TaurusValueLineEdit will parse its contents using pint's parser (when dealing with numerical models).

S, instead of closing, I'll keep this issue open as a reminder for documenting (I'll change the title accordingly)