Show HN: Dollar and Cent – A functional tool belt for Swift

[GuiA]

first Returns the first element in the array and terminated the chain

second Returns the second element in the array and terminated the chain

third Returns the third element in the array and terminated the chain

fourth Returns the fourth element in the array and terminated the chain

fifth Returns the fifth element in the array and terminated the chain

sixth Returns the sixth element in the array and terminated the chain

seventh Returns the seventh element in the array and terminated the chain

eighth Returns the eighth element in the array and terminated the chain

ninth Returns the ninth element in the array and terminated the chain

tenth Returns the tenth element in the array and terminated the chain

... is this a joke?

[SoftwareMaven]

Quite common, actually. Check out the Racket list documentation[1] or the Common Lisp list docs[2], for example.

1. http://docs.racket-lang.org/reference/pairs.html

2. http://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node149.html

[agp2572]

Is Rail's ActiveSupport a joke?

https://github.com/rails/rails/blob/a31277011814b7bdb6be41a8...

[sanderjd]

It's pretty interesting to compare the extent to which different libraries take this idea. I think tenth is the furthest I've seen. I find first and last useful frequently, but I think the furthest of these ordinals I've ever used in real code was second or maybe third.

[Karunamon]

Not really, it's just a way to make your code more expressive in a different way, I can see it helping in some cases since arrays are zero-indexed.

arr.first is more immediately expressive to me than arr[0] - but this is a matter of opinion :)

[dxbydt]

https://github.com/scala/scala/blob/v2.11.1/src/library/scal...

[agp2572]

Dollar is a Swift library that provides useful functional programming helper methods without extending any built in objects. It is similar to Lo-Dash or Underscore in Javascript.

Cent is a library that extends certain Swift object types using the extension feature like ActiceSupport in ruby and gives its two cents to Swift language.

[randomguy7788]

its unfortunate that it repeats the same mistakes that underscore and lodash does (imo) and makes it very hard to do composition (data comes in first instead of the predicate/function)

[ankurpatel]

The plan is to implement extensions as well.

[lsdafjklsd]

Not so much functional as just useful methods for working with arrays / maps. It would be functional to include a compose method... also currying is going to be painful because of how the arguments are structured (data first).

[vilya]

I don't understand why every result is stored into the same class-level variable. What's the aim behind that? It just seems like it would introduce unexpected behaviour without any gain, but I don't really know swift yet so maybe there's something I'm missing?

[agp2572]

Static methods are defined using class keywork.

[MrGando]

Hate this stuff, Swift != Javascript.

[ankurpatel]

Haters gonna hate :)

But really functions are first class citizens in Swift and it is designed to be a hybrid between OO and functional programming language. It doesn't implement some of the common helper functions like pluck, difference, intersection, etc. This is where this or another library comes in.

[jaxytee]

A lot of these functions transcend javascript, and are a product the functional world.

[Nekorosu]

It's not Objective C also. Move on. The new world awaits.

Though dollar swift is a little bit cheesy for my taste.