Torturing Rustc by Emulating HKTs

Torturing Rustc by Emulating HKTs(harudagondi.space)

76 points by g0xA52A2A 65 days ago | 7 comments

mmastrac 61 days ago |

I've been playing around with type mapping like this in a highly experimental crate. The ability to map, filter and reduce types is insanely powerful but it's tough to get ergonomic syntax.

https://docs.rs/tuplemagic/latest/tuplemagic/index.html

selfmodruntime 61 days ago |

I also hit a funny compiler end-of-the road last month when I wanted to try out generic_const_exprs for my RFC8366 implementation:

  pub struct VoucherDetails<C>
    where
      C: CapacityConfig,
      [(); C::SERIAL_NUMBER_MAX]:,
      [(); C::MANUFACTURER_PRIVATE_MAX]:,
      [(); C::IDEVID_ISSUER_MAX]:,
      // <imagine a dozen more properties here>
      [(); C::NONCE_B64_MAX]:,
  { ... }

The heavy const eval + trait resolution was too much even for my M2 Pro.

amluto 61 days ago | |

Nice.

You inspired me to look up RFC8366. That's a remarkable document, apparently written in English, where at least the abstract and introduction look like they might be the result of a particularly nerdy game of Mad-Libs. :)

I, personally, have never observed a pledge doing anything other than being heard, although I observed Lemon Pledge smelling unpleasant. But, in RFC8366, pledges can join domains!

(I assume that a manufacturer makes a device and the device somehow contains a "pledge" from the manufacturer that the device is what it says it is...)

selfmodruntime 59 days ago | | |

You assume almost correct, the device is the pledge itself! RFC8366 is used (among others) in the BRSKI protocol family. For device attestation purposes in 802.1x Networks, a pledge comes with a manufacturer provided public key material, often a certificate but not always, that links it to the manufacturer via a publicly available trust root. In an exchange process, the customer - called the registrar in the specification documents - then asks for and verifies the pledge's key material before issuing their own domain certificates.

It's in essence an automated zero-trust-ish protocol for network join purposes :)

cptroot 61 days ago |

This was incredible, even as it rapidly outpaced my PL and mathematics knowledge.

PeterWhittaker 61 days ago | |

Like I said to a friend, I know just enough category theory to know that I do not understand. Perhaps upon Nth reading.

spartanatreyu 61 days ago | |

I think I'll just point to this post the next time some asks me what getting nerdsniped means.

pub struct VoucherDetails<C> where C: CapacityConfig, [(); C::SERIAL_NUMBER_MAX]:, [(); C::MANUFACTURER_PRIVATE_MAX]:, [(); C::IDEVID_ISSUER_MAX]:, // <imagine a dozen more properties here> [(); C::NONCE_B64_MAX]:, { ... }