Hacker News: Peaker

New comment by Peaker in "This AI is bad at drawing but will try anyways"

Peaker — Tue, 21 Aug 2018 07:32:37 +0000

And this is why they need human brains in The Matrix

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Wed, 18 Jul 2018 20:01:39 +0000

A type-class or just a callback type, vs pattern-matching, yeah.

New comment by Peaker in "Async and Await in Rust: a full proposal"

Peaker — Sun, 15 Jul 2018 20:17:19 +0000

There's a huge advantage to not everything being async/await. Knowing exactly when you yield control can give you atomicity and more determinism for free.

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Sun, 15 Jul 2018 20:15:47 +0000

Then what you have is not "anything". You have an expression problem:

Either each element has some "handler" that does the right thing for that data type.

Or you have a set of cases that each data can be, and you handle them all.

Neither is just "any type". And static types are very suitable to describe either.

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Sun, 15 Jul 2018 20:14:22 +0000

Everything is of course possible, but at what cost?

In my experience, with large projects, you get to pick 2:

Dynamic typing Development velocity Reliability

I've seen multiple large projects grind to a near halt in their development speed, and I've seen some retain development speed, but unreliably crash after various changes.

UT coverage is expensive. System tests don't catch everything. Either you fear changes, and the system rots, or you work very slowly with coverage for everything.

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Sun, 15 Jul 2018 14:37:50 +0000

When do you have lists of lists of elements of any type?

What can you even do given such a value?

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Sun, 15 Jul 2018 14:37:17 +0000

That's great for functions you just wrote. It's not as great for functions you change in a large code base.

New comment by Peaker in "Lisp and Haskell (2017)"

Peaker — Sun, 15 Jul 2018 14:33:42 +0000

Rust is a great systems language.

When I write applications, I don't need a systems language, and Haskell is easier to use.

Also, Rust is a great imperative language, it's not as great as a functional language, and you can't reap the benefits of pure functional programming.

New comment by Peaker in "In the Philippines, Dynamite Fishing Decimates Entire Ocean Food Chains"

Peaker — Tue, 19 Jun 2018 07:55:57 +0000

An average US citizen contributes far more to pollution than the average African or Asian.

New comment by Peaker in "Robust Clojure: The best way to handle nil"

Peaker — Sat, 02 Jun 2018 18:09:12 +0000

There are various library-level implementations. Here's the first one that turned up on Google:

https://raw.githubusercontent.com/target/row-types/master/ex...

New comment by Peaker in "Robust Clojure: The best way to handle nil"

Peaker — Thu, 31 May 2018 14:21:54 +0000

Haskell has reasonable implementations of row types as well.

New comment by Peaker in "Space Is Full of Planets, and Most of Them Don't Even Have Stars"

Peaker — Wed, 30 May 2018 05:39:14 +0000

Life on Earth started within a few hundred million years, not 2 billion years.

New comment by Peaker in "Robust Clojure: The best way to handle nil"

Peaker — Tue, 29 May 2018 20:19:39 +0000

I suspect the problem is mentoring. It took me months to get basic Haskell.

The people I mentored, though, could clarify any misunderstanding and get explanations from multiple viewpoints from me -- after years of experience with these abstractions. With such mentoring, you don't have to go through all the confusion phases.

New comment by Peaker in "Robust Clojure: The best way to handle nil"

Peaker — Tue, 29 May 2018 20:18:13 +0000

Haskell record syntax with lenses is workable:

  import Control.Lens

  data MyRecord = MyRecord { _a :: Int, _b :: MyRecord }
  makeLenses ''MyRecord

Then you can use it nested like:

  over (b . b . a) (+5) myRecord

New comment by Peaker in "Robust Clojure: The best way to handle nil"

Peaker — Mon, 28 May 2018 21:17:18 +0000

I've mentored programmers in Haskell and they were also productive within a few weeks.

I'm pretty sure I could get a student to write useful Haskell code in that time span with just mentoring and existing documentation material.

New comment by Peaker in "The Logical Disaster of Null"

Peaker — Thu, 10 May 2018 13:41:26 +0000

That's the Maybe type. The Maybe monad is this:

  instance Monad Maybe where
    return = Just
    Nothing >>= _ = Nothing
    Just x >>= f = f x

(And is not really related to the discussion)

New comment by Peaker in "The Logical Disaster of Null"

Peaker — Thu, 10 May 2018 13:39:26 +0000

Destroying a language's safety for a single use case is a terrible trade-off.

There are various possible solutions for circular structures that do not require destroying all static safety with nulls everywhere.

New comment by Peaker in "Is sorted using SIMD instructions"

Peaker — Sun, 15 Apr 2018 09:31:27 +0000

Isn't the bottleneck in any sequential access case the memory bandwidth?

IOW: Are the scalar instructions slower than memory bandwidth?

New comment by Peaker in "The joy of max()"

Peaker — Wed, 04 Apr 2018 10:15:59 +0000

Of course that's true. But Lisp is shitty at controlling memory use, indirections, and manual MM.

New comment by Peaker in "The joy of max()"

Peaker — Sun, 01 Apr 2018 18:07:21 +0000

They're not really "inheritance". They can do what inheritance can do, and much much more.