--- Dupont Corentin
Salut,
Personne ne peut me répondre sur mon erreur ci-dessous? comment caster de Float en Double?
If you really need a datatype for a Point you may use something like : Num a => Point a a specifying that: I) a may be every numeric type and II) a point is something which includes 2 pieces of date which belongs to that type a. As a result the system will use the needed kind of points everywhere. 2)
J'ai d'autres questions: Je n'ai pas très bien compris ce que signifie le '. Apparemment ça a à voir avec l'impératif...
Nothing special. It is like _ in other languages.
Je ne comprend pas très bien ce que font des opérateurs comme &&&: (&&&) :: (Arrow a) => a b c -> a b c' -> a b (c, c') Translation: In the hypothesis that a is a type froma a class of types called Arrow then the type of the &&& function (operator) is: a b c -> a b c' -> a b (c, c')
Remark: you may presume that a and b are type constructors (like m for monads). So: a b c means: the a type constructor applied to ( b type constructor applied to a data fromthe type c). This is a complex datatype. a b c' means: the a type constructor applied to ( b type constructor applied to a data the type c'). This is a complex datatype. c' may or may not be the same with c. a b (c, c') means: the a type constructor applied to ( b type constructor applied to the pair formed by last c and last c'). This is a complex datatype. c' may or may not be the same with c but both are the previously c and c', now alltogether. (c,c') means: pair made by c and c'
Dans la signature, que signifient les espaces entre les a,b,c...?
Application of the typeconstructor from the left to the datatype from the right. It's something like: a(b(c)) in mathematics.
Merci! Corentin
You are wellcome ! Dan P.S. Can I use the question rised, for example as examples for my students or by posting them to haskell.org in any language ? Or would you like to translate the explanations in french for Haskell-fr ? ____________________________________________________________________________________ Pinpoint customers who are looking for what you sell. http://searchmarketing.yahoo.com/