tuples and cartesian coordinates

[Steve Horsley]

Gerrit Holl wrote:
> Hi,
> 
> the FAQ says:
> 
> 
>>For example, a Cartesian coordinate is appropriately represented as a
>>tuple of two or three numbers.
> 
> 
> I find it strange to use tuples for a coordinate. After all, a
> coordinate represents a position of an object. Suppose I have a game
> where the player has a position: isn't it stupid to use tuples rather
> than lists or another type (maybe complex numbers?), because I want to
> be able to change the position?
> 
> Shouldn't coordinates be mutable?
> 
> yours,
> Gerrit.
> 

Depends. Does it make logical sense for the coordinate to be mutable 
in the context of your app?

If an object is returning an instrumentation value, as in
     positionNow = spaceship.getPosition()
then it does make sense to be mutable. Of course the spaceship itself 
may well keep a mutable position internally that it changes in 
response to
     setThrusters(fullSpeedAhead)

Steve