TheAsprngHacker
Joined 9 years ago
Karma
873
Submissions
212
Member since
Nov 3
Recent submissions
Comment · 5 years ago
Comment · 5 years ago
This is a Rust library for reading and writing the LEB128 integer compression format. LEB128 is a representation of arbitrary-size integers: https://en.wikipedia.org/wiki/LEB128
As I understand it, this library is optimized to avoid branching (which incur an overhead) and take advantage of SIMD instructions (which process data in parallel).
Comment · 6 years ago
I said this in my other reply, but if you can implement a language feature as a local rewrite, it does not add expressiveness. Features that add expressiveness must involve some sort of non-local transformation. A language feature adds expressiveness iff two programs that are equivalent in the base language in all evaluation contexts are not equivalent in the extended language. Felleisen came up with this idea in a paper, which Shriram Krishnamurthi explains in this video: https://pwlconf.org/2019/shriram-krishnamurthi/
Comment · 6 years ago
You can have recursion right from Beginning Student Language (which lets you define top-level functions and call them recursively). Structural is taught early, together with lists. Structural recursion is explained together with recursive data: To unpack the data (any data, not just recursive), unpack the inner members, and therefore the structure of the program follows the structure of the data.
As someone who is taking the accelerated version of this course right now, but had prior functional programming experience, I did feel limited at first. Some other people responded negatively to the student languages because they weren't "mainstream."
As for the expressive power of languages, as a matter of fact, Felleisen wrote a paper that rigorously defines this idea. Here is a talk by Shriram Krishnamurthi that discusses it: https://pwlconf.org/2019/shriram-krishnamurthi/ It turns out that local transformations (macros) do not add expressive power. A language feature adds expressive power if you can find two programs that are observationally equivalent in the base language, but not the extended language.
Comment · 6 years ago
The approach of incrementally introducing language features is what Matthias Felleisen advocates: https://felleisen.org/matthias/Thoughts/Developing_Developer... Felleisen's argument is that all general-purpose languages are too big to be appropriate for teaching, and you should use specialized teaching languages. In Northeastern University's introductory programming class, students start with a minimal Scheme called Beginning Student Language (which has primitives, function application, if, cond, and top-level define), then move up to Intermediate Student Language (which adds local), then Intermediate Student Language with Lambda (which adds function literals). Each addition is given a motivation (locals let you avoid repeat computations, local functions let you capture the environment, lambdas let you use local functions without giving them a name).
But Hedy seems to make the mistake that many curriculums do of focusing on the minutiae of syntax. Don't do that! Northeastern's course emphasizes broad concepts such as abstraction, accumulators, and generative recursion. Meanwhile, it uses simple s-expr syntax.
Comment · 6 years ago
UIP is uniqueness of identity proofs. It's an axiom that says that all proofs of x = y (that two terms are propositionally equal) are the same.
Now, UIP is valid if the only way of proving an equality is to show that the two terms are definitionally equal. However, there are various type theories, such as Homotopy Type Theory, in which this axiom does not hold because propositional equality can have other proofs.
Comment · 6 years ago
https://utteranc.es/ is a project that allows you to add comments to a page using GitHub issues.
Andrej Bauer's blog also uses GitHub issues for comments: http://math.andrej.com/
Comment · 6 years ago
Interestingly, documentation that's only type signatures is also a frequent gripe I've heard about OCaml. So maybe this is a universal phenomenon.
However, some people contrast OCaml and Rust in this regard, contradicting the views of the great grand-parent comment: https://news.ycombinator.com/item?id=25111104
Comment · 6 years ago
Have you tried OCaml? F# is a derivative of OCaml, and of course the OCaml ecosystem is non-.NET.
Comment · 6 years ago
The two-party system is not a consequence of the lack of access to money. It is a consequence of the first-past-the-post system, which will always trend towards two parties (as a matter of game theory). See https://en.wikipedia.org/wiki/Duverger%27s_law.
The problem of primaries selecting for extremists could be partially alleviated with ranked-choice voting, so an extreme candidate with a significant minority of supporters can't win against a divided field of moderates. This is how Trump won the 2016 Republican nomination and how Sanders almost won the 2020 Democratic nomination before the establishment candidates dropped out and endorsed Biden. Or, we could try open primaries so independents can give input on the desired candidate.
Comment · 6 years ago
This blog post seems to discuss what you say: https://rosenzweig.io/blog/my-name-is-cafe-beverage.html
> Reuters conducted polls in December 2019,[617] March 2020,[618] June 2020[619] and August 2020. The last poll showed that an increasing number of Hongkongers support the pro-democracy goals since the national security law was implemented. More than half of the respondents opposed the national security law. 70% wanted an independent commission of inquiry that looked into how the police handled the protests. 63% wanted universal suffrage. The support for amnesty of all arrested protesters rose to 50%. More than half of people still wanted Carrie Lam to resign. The number of people who opposed the pro-democracy demands went down to 19%. The majority (60%) still opposed Hong Kong independence, 20% supported the idea.[620]
https://en.wikipedia.org/wiki/2019%E2%80%9320_Hong_Kong_prot...