Dennis Decker Jensen wrote:

# M.Tanaka:
# #  >   Units(3,'cm') + Units(2,'inch') #=> Units(8.08,'cm')
# # 
# #  I put the product at
# # 
# #    http://www.ir.isas.ac.jp/~masa/ruby/index-e.html#units

Hopefully also referenced on RAA.

# #  I wonder there is more suitable name than "class Units".
# 
# Quantity is one option. Value might be another, or maybe even
# WholeValue.

Well, there is a whole field of dimensional analysis that deals with
units of measure. So "class Dimensions" might be a better choice with
respect to (somewhat) conventional terminology.

However, "class Units" is actually a pretty good choice, despite
the fact that the term "units" is somewhat ambiguous (e.g. it might
sometimes refer to unit tests, refrigeration units, instances of
something, military and business groups, and so on). OTOH,
"dimensions" is also a somewhat ambiguous term. A simple solution is
just more qualification, e.g.  "class Units_of_measure" or
"class Dimensional_math".

Conrad Schneiker
(This note is unofficial and subject to improvement without notice.)