Comp150CPA Message 0023.txt from Alva L. Couch(couch)

OOPS! I made an error on this page: 
Q: How can I get the bud simulator to work? It doesn't seem to... 
A: I played with it a bit just now and made sure that I installed
   it correctly. 

FLASH: I made an error in the following example: 

rebl> table :friends, [:f1,:f2]=>[:f3]
rebl> friends <= [['alva', 'george', 1]]
rebl> friends <= [['alva', 'fred', 1]]
rebl> stdio <~ friends
rebl> /tick
exception: Exception during Bud evaluation.
Exception: #<Bud::KeyConstraintError: Key conflict inserting ["alva", ["fred", 1]] into "stdio": existing tuple ["alva", ["george", 1]], key_cols = ["alva"]>.
Rule: stdio < (friends.~)

The reason that this didn't work is that I should have written 
 	stdio <~ friends.inspected
rather than 
	stdio <~ friends

Note: I took my lecture examples from the "bud cheat sheet" on the website. 
I was expecting you to do the exam *without* invoking the simulator. 
It is possible to do just from the "meanings" of the operators. 

Last changed Tue May 10 17:40:04 2011