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liamoc.net
Personal blog · liamoc.net/postsprogrammingphilosophy
liamoc.net is a personal blog at liamoc.net about programming and philosophy. Since 2010, 15 different Hacker News readers have linked it 16 times, most often “Against Curry-Howard Mysticism”. The last post was in 2017, but the archive is still widely read.
Too few sampled comments (6) to say how often HN recommends it.?
Why HN links it
Essays on type theory and type systems, including arguing against Curry-Howard mysticism, whether Rust is affine, and type checker design. Also a Haskell patch theory library post.
Summarised by Claude from a sample of 6 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- Against Curry-Howard Mysticism6 people · 7 mentions · first linked 2025-05-26
- The Theory of patches-vector2 people · 2 mentions · first linked 2015-11-10
What Hacker News says?
Yeah, that makes sense. The Rust type system isn't "affine" as in affine logic. Rust allows different forms of contraction, which affine logic strictly prohibits. And some people like to claim that the Curry-Howard correspondence proves something about their type system, but this is only true for dependently typed languages. And the proofs aren't about program behavior. See, https://liamoc.net/forest/loc-000S/index.…
Comment linking /forest/loc-000S/index.xml
on “Tree Borrows”Submitted Writing a Compiler by Proving It Correct as a story · 139 points
HN discussionThe main point of Affine logic is that it doesn't allow contraction, and the Rust type system does allow different forms of contraction. How exactly is Rust an "affine language"? Also, the claims about Curry-Howard correspondence are wrong. It does not prove that rust is an affine language: https://liamoc.net/forest/loc-000S/index.xml But Swift DOES have affine types with the "Non copyable" types that doesn't allow…
Comment linking /forest/loc-000S/index.xml
on “Tree Borrows”Submitted Domain Theory Lecture Notes as a story · 61 points
HN discussionThey are a false idol in that, when people learn about them they seem like they’re the answer to all problems, and they’re not. The fact that types are equivalent to propositions doesn’t mean that making all of the propositions about your code at the type level is a good idea. For me, it’s completely unnatural, clunky, and more verbose than just writing propositions as logical statements. I found this talk from Xavi…
Comment linking /posts/2015-08-23-verified-compiler/index.html
on “Chris Lattner left Swift core team”Submitted Safe: Robust programming in Haskell via types, testing, debugging as a story · 39 points
HN discussionThis seems to jump straight into type inference and bidirectional type checking, without a basic UNI-directional type checker e.g. Featherweight Java (chapter 19 of TAPL by Pierce) is expressed with a simple unidirectional algorithm And some of the languages in the PL Zoo - https://plzoo.andrej.com/ like https://github.com/andrejbauer/plzoo/blob/master/src/sub/typ... , although I am not quite sure related thread: ht…
Comment linking /forest/loc-000S/index.xml
on “Typechecker Zoo”Submitted The Theory of patches-vector as a story · 22 points
HN discussionI think it is time to repost Against Curry-Howard Mysticism ( https://liamoc.net/forest/loc-000S/index.xml )
Comment linking /forest/loc-000S/index.xml
on “Mathematicians will probably become obsolete before anyone else [pdf] (2004)”Submitted Against Curry-Howard Mysticism as a story · 5 points
HN discussionProbably not what you mean, but there's an alternative patch theory implementation as a Haskell library: http://liamoc.net/posts/2015-11-10-patch-theory.html
Comment linking /posts/2015-11-10-patch-theory.html
on “VCS based on categorical theory of patches (2017)”Submitted Against Curry-Howard Mysticism as a story · 5 points
HN discussionSubmitted Imperative Reasoning Is Hard as a story · 4 points
HN discussionSubmitted Imperative Reasoning is Hard as a story · 4 points
HN discussionSubmitted Against Curry-Howard Mysticism as a story · 3 points
HN discussionSubmitted The Trouble with Typing Type as Type (2015) as a story · 1 points
HN discussion
