Map function is crowded about fantasy-land HOT 2 CLOSED

Names have come up before : #51

from fantasy-land.

I think there is a misunderstanding.

I'm not complaining about the name map or fmap for aesthetic reasons which appears to be what is happening in issue #51.

My issue is that the name map has already been taken by existing projects that we we might want to use. To give a concrete example:

I want Array.prototype.map to have the signature [a] -> (a -> b) -> [b] but the existing implementation has the signature [a] -> (a -> num -> [a] -> b) -> [b]. All those extra arguments in the iterator will bust up a curried function, so there is a good reason to want it to have the same signature across the board. If map wasn't already defined on the Array prototype I could just define it myself but it is and now I'm out of luck because map is the function that fantasy-land wants on the object and it's defined in a bad way.

Another example.

jQuery objects wrap up DOM nodes, I want to expose the functor interface of jQuery so that I can interoperate with fantasy-land things. jQuery objects already have the functor's map method so I should be in luck, unfortunately the signature is jQuery Element -> (Number -> Element -> a) -> [a]. If we were using a different name for the functor's map method then I could just fill it in on jQuery myself and I would have full interoperability with all my other functors.

jQuery.fn.extend({
  // :: jQuery Element -> (Element -> a) -> [a]
  fmap: function(fn) {
    return this.map(function(index, domElement) {
      return fn(domElement);
    });
  }
});

Note, I've used the name fmap in the above example but I don't really care what it's called - just something that isn't taken by other existing implementations.

from fantasy-land.