Implement Predicate combinators #98 #102
Conversation
|
@mperry can you please have a look? please provide feedback. |
|
On my list of todos. |
|
:) thanks |
| public static <A, B> F<B, Boolean> contramap(F<B, A> f, F<A, Boolean> p){ | ||
| return compose(p, f); | ||
| } | ||
|
|
There was a problem hiding this comment.
Isn't this mapping over a function, rather than a contramap? E.g. F1W.lift(...).map(....)
There was a problem hiding this comment.
technically it's a contramap, because it's applying function to input of F<A, Bool> (negative position)
There was a problem hiding this comment.
I see now, it is contramapping over the predicate, whereas I was thinking it was mapping over the first function. It looks like these two cases are equivalent here, but given we are focused on predicates contramap is appropriate for the name.
|
In summary, need to resolve |
|
@mperry thanks, you will see changes in a branch henceforth. |
|
I think the names are fine as is. Specifically, I think Here are some considerations:
In some older Haskell libraries, with use of contravariant functors, the name Unlike for invariant (exponential) mapping, where I have seen several different names, for the same type of mapping; |
|
Data.Function.Predicate (http://hackage.haskell.org/package/predicates-0.1/docs/Data-Function-Predicate.html) uses |
|
Hi @amarpotghan, why did you close this PR? |
No description provided.