[cap-talk] Potting the web-calculus in a paragraph

[Sandro Magi]

Bill Frantz wrote:

>On 12/15/05, smagi at naasking.homeip.net (Sandro Magi) wrote:
>  
>
>>So a brand can be likened to a class. Can anyone elaborate on the 
>>differences from a class?
>>    
>>
>
>In general, class is a compile-time notion.  Brands are more run-time.
>
>One place I have seen brands used is in digital money demos.  You define
>a class called purse.  Each type of currency (think Euro, Dollar etc.)
>has its own brand.  Purses can transfer funds between themselves if they
>are of the same currency.  They use brands to identify whether the other
>purse in a transfer has the same currency.  While two purses with
>different brands are instances of the same class, the brand difference
>means they represent different currencies.
>  
>

Thanks for the clarification.

This sounds like units in measurement, where a Measurement is a class 
whose instances encapsulate a numeric quantity and units; certain 
operations generate a new set of units (ie. division), and certain other 
operations (ie. comparison) is only possible between measurements with 
the same units.

Sandro