[Haskell-cafe] comprehension problem

[ptrash]

Hi,

what does this to code rows mean:

newtype Probability = P Float
newtype Dist a = D {unD :: [(a, Probability)]}

newtype definies a new type called Probability. But what does P Float mean?

And what is the a in Dist a? 
What does D {...} mean?

Thanks for your help.
-- 
View this message in context: http://www.nabble.com/comprehension-problem-tp23858359p23858359.html
Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.