Arc Forumnew | comments | leaders | submitlogin
1 point by Pauan 4735 days ago | link | parent

...because each does not map. Nor does it some. Nor does it mappend. Nor does it all. Nor does it keep. Nor does it rem.

I don't think you understand what I'm talking about. In Arubic, map is just a macro that expands into mapfn. The semantics are exactly the same as Arc 3.1, it's just easier to say...

  (map x foo ...)
...rather than:

  (map (fn (x) ...) foo)
The only point of it is to remove the (fn ...) bit, resulting in shorter and easier to read code.


1 point by akkartik 4735 days ago | link

...because each does not map. Nor does it some. Nor does it mappend. Nor does it all. Nor does it keep. Nor does it rem.

Sorry, that makes no sense to me.

Focus on just map. Are you saying it doesn't return a transformed list? Ok. But can we call it something different? You'll have to pry

  (map car xs)
from my cold dead hands :)

-----

1 point by Pauan 4735 days ago | link

"Focus on just map. Are you saying it doesn't return a transformed list?"

No. You are still misunderstanding me. I will be as clear and precise as I possibly can. In Arc 3.1, you call `(map x foo)` where `x` is a function and `foo` is a list.

In Arubic, you would say that as `(mapfn x foo)`. It's exactly the same, except you use the name `mapfn` rather than `map`. Now, Arubic also provides a macro called `map`, which expands into `mapfn`. In other words:

  (mac map (var x . body)
    `(mapfn (fn (,var) ,@body) ,x))
The sole purpose of this macro is so that you don't need to type out the `(fn ...)` part in `(mapfn (fn (x) ...) foo)`. That's it. The meaning of `map` is the same, it's just that now that it's a macro, it's a lot more convenient to use. But you can still pass in a function directly by using `mapfn`.

---

"You'll have to pry (map car xs) from my cold dead hands :)"

If you dislike any parts of Arubic (whether misunderstood or not), simply do not use those parts. The point of the namespace system is that you can change what you want and use what you want, rather than being tied down to one semantic/syntax/meaning/language. Thus, it is possible (and relatively easy) to use some of the things from Arubic that you like, while not using the parts you dislike.

In this particular case, however, you are misunderstanding me. Your example would be `(mapfn car foo)` in Arubic.

-----

1 point by akkartik 4735 days ago | link

In this particular case, however, you are misunderstanding me. Your example would be `(mapfn car foo)` in Arubic.

No, I'm now pretty sure I'm not misunderstanding you.

My entire objection is to the name switch. Of course I know I can change the default. It's not a sensible default, it's like defining 1 to be 0.99. You're fragmenting the semantics of a name that has thus far had a pretty clear meaning. You're welcome to do this, but it's going to hinder users with any programming background.

I don't understand why the thing you want must be called map. Why not mapmc, for example? Or some other 3-letter name?

-----

1 point by Pauan 4735 days ago | link

"My entire objection is to the name switch. Of course I know I can change the default. It's not a sensible default, it's like defining 1 to be 0.99."

It's not the default. The default is Arc 3.1. You have to opt-into Arubic. In any case, how is it not sensible? It provides the shortest, easiest to read, and fastest code.

---

"You're fragmenting the semantics of a name that has thus far had a pretty clear meaning."

And this is why I think you're still misunderstanding me. The meaning of map is the same. It's just that now you can write (map x foo ...) rather than (map (fn (x) ...) foo), which is shorter and easier to read.

If you're worried that it'll mess up Arc programmers who are used to the naming of map, then as already said, Arc 3.1 is the default. You only get the new syntax if you import Arubic.

I do not see how changing the meaning of names in a new language is a bad thing. That's like me saying that wart should use exactly the same names as Arc, which is absurd: they're different languages. If you want to use a different name for something in wart, then go for it.

Perhaps you still do not grasp that Arubic is a different language from Arc, implemented in a separate namespace so as not to mess up Arc's namespace.

---

"I don't understand why the thing you want must be called map. Why not mapmc, for example? Or some other 3-letter name?"

....

I'm done arguing. Goodbye.

-----

1 point by akkartik 4735 days ago | link

"I'm done arguing. Goodbye."

Suit yourself. I don't understand what I have said to merit hostility.

I know we can all do what we want. I also am aware of lots of things I can try if I don't like something you do. I don't understand these defensive reactions. Was I rude somewhere?

All this while you keep insisting you know what I am misunderstanding. Is that not rude?

Arubic's map is a macro, not a function. Until it grows fexprs the meaning is by definition not the same.

"This is how I like it" is a perfectly valid reason (and would have ended this conversation eons ago). Just don't insist it's all still the same when it isn't.

-----

1 point by akkartik 4735 days ago | link

I do not see how changing the meaning of names in a new language is a bad thing.

That's an equally good response to any feedback you get.

Do you seriously think changing the meaning of 42 is a 'good' thing?

I don't even feel that strongly about this conversation. It's only gone on so long because:

a) You kept insisting I am too dense to comprehend your subtle creations.

b) You kept insisting you're changing nothing.

-----

1 point by akkartik 4735 days ago | link

It's not the default. The default is Arc 3.1.

No, the default is racket. No, it's machine code. Or is it cosmic background radiation? WTF, are you seriously saying that creating a new language isn't an act of choosing defaults?

-----

2 points by rocketnia 4734 days ago | link

In Nu, the default namespace is the one corresponding closely with Arc 3.1. And in this namespace, the default definition of 'map is pretty much Arc 3.1's. Therefore, "it's not the default" is true in Nu.

Another namespace in Nu is Arubic. Using this namespace is like using a language other than Arc 3.1, where 'map is a macro. If your problem is with Arubic itself, you're free to ignore the parts of Arubic you don't like (even if you want to use an library written in full Arubic). If the point is you think people shouldn't dilute the overall meaning of "map" with the meaning Pauan gives it in Arubic, that's a moral position, with Pauan as an unintentional villain!

---

What I think is that the meaning of "map" isn't tainted here, at least not any more than usual. In fact, I wanted 'map to be an 'each -like macro before I knew Pauan had the same thing in mind.

If I don't know what language we're talking about and I hear "map," I assume it'll be an abstraction that applies a given transformation to elements of a given data structure (whatever "abstraction," "transformation," "data structure," and "given" mean), along with some accidental complexity suitable to the language, such as the timing of computation, side effects permitted in the transformation, or late-bound dependencies (like 'map calling out to 'cons, such that rebinding 'cons changes what happens).

In a language where macros like 'after and 'each are more convenient to use than higher-order functions like 'protect and Anarki's 'trav, a macro for map is to be expected.

In Arc, almkglor[1] calls this macro "mapeach" in Anarki, and I call it "maplet" in Lathe. Pauan and I call it "map" as long as we don't have naming conflicts to worry about. As long as this macro is the primary way we use the map concept, using that name keeps our programs brief and frank.

[1] I'm not sure about this credit, but I found it at https://github.com/nex3/arc/blame/arc2.master/arc.arc and verified it with a Web search.

-----

2 points by rocketnia 4734 days ago | link

Whoops, Anarki's 'trav is a macro. I meant 'walk. ^_^;

-----