Browse thread
Same label in different types, how do people solve this?
[
Home
]
[ Index:
by date
|
by threads
]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: | 2000-12-11 (17:47) |
From: | Pierre Weis <weis@p...> |
Subject: | Re: Same label in different types, how do people solve this? |
> Mattias Waldau wrote : > > In Ocaml, you cannot have the same label in different types, see the > example > > below where point_2d hides point_3d. > > Troublemaker :-). There is a thread on this topic on comp.lang.functional. > Please, FAQ maintainer, this is very definitely FAQ material! Feel free to propose an entry for the FAQ (in english and french please): I would be glad to add it. [...] > Pierre Weis wrote > > I would suggest another syntactic notation to specify the type to > > which a label belongs: label@@type. > > > > {x@@p2d = 0; y = 5} > > r.x@@p2d > > I don't want to start a syntax war, but I think Ocaml is already suffering > a bit from too much added syntax and this doesn't look good to me. Jacques' > reuse of ":" (I know, it applies to the whole record and not a label) is > easier on my eyes, which already associate ":" with typing. > > -- Brian The notation I suggested is simpler to implement and specify: there is nothing new in type constraints propagation and label overloaing resolution strategy: just a notation to specify the type to which a label or constructor belongs to in the same spirit as usual qualification of names in the module system. Pierre Weis INRIA, Projet Cristal, Pierre.Weis@inria.fr, http://cristal.inria.fr/~weis/