indexing

Sound unchecked indexing using “generativity”; a type system approach to indices, pointers and ranges that are trusted to be in bounds.

APACHE-2.0 License

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indexing

“Sound unchecked indexing” in Rust using “generativity” (branding by unique lifetime parameter).

Extremely experimental, but somewhat promising & exciting.

Main focus is on index ranges, not just single indices.

|build_status|_ |crates|_

.. |build_status| image:: https://travis-ci.org/bluss/indexing.svg?branch=master .. _build_status: https://travis-ci.org/bluss/indexing

.. |crates| image:: http://meritbadge.herokuapp.com/indexing .. _crates: https://crates.io/crates/indexing

Crate Features:

  • use_std Enabled by default, disable to be no_std-compatible.

References

  • Inspired by Gankro’s exposition of sound unchecked indexing__.

__ https://www.reddit.com/r/rust/comments/3oo0oe/sound_unchecked_indexing_with_lifetimebased_value/

Also now described in: You can't spell trust without Rust <https://raw.githubusercontent.com/Gankro/thesis/master/thesis.pdf>_. Chapter 6.3 hacking generativity onto rust. Gankro's master's thesis.

Recent Changes

  • 0.4.1

    • Remove the ability to clone non- FixedLength Containers,
      because allowing to clone a container was wrong in the presencen of the
      length changing .push()/.insert() methods on vectors in containers.
  • 0.4.0

    • Add method .make_twin() that allows two or more containers
      to use the same trusted indices, if they are the same size
    • Add new marker trait FixedLength for use in make_twin.
    • Remove the branded raw pointer features, since they need revision (See #11)
    • Fix bug in the proof of .join_cover()
    • Fix signatures in ContiguousMut so that it now uses &mut correctly
    • Update dev-dependencies
    • Add Ord, PartialOrd impls for Range
    • Now using Rust 2018 and requiring Rust 1.32 or later.
  • 0.3.2

    • Fix future compatibility warning about pointer casts.
    • Add Ord, Hash impls for Index and Hash for Range
  • 0.3.1

    • Fixes in tests
    • Add crates.io categories
  • 0.3.0

    • Tweak implementation traits a bit, PointerRange, Provable,
      ContainerRef, make them unsafe where needed.
    • Add Container::range_of
  • 0.2.0

    • Docs are better
    • Refactor most of the crate, prepare for other backends than slices
    • Expose PIndex, PRange, PSlice which are the pointer-based equivalents
      of safe trusted indices and ranges. Some algos are better when using
      a raw pointer representation (for example: lower bound). Since we don't
      have HKT, traitifying all of this is not so pleasant and is not yet complete.
    • New feature: can combine trusted indices with push/insert on Vec.
  • 0.1.2

    • Add binary_search_by and lower_bound to algorithms. Algorithms
      don't require T: Debug anymore.
  • 0.1.1

    • Point documentation to docs.rs
  • 0.1.0

    • Add some docs and tests
    • Fix Range::join_cover_both to use ProofAdd
  • 0.1.0-alpha3

    • Add IndexingError and use it for all Results.
  • 0.1.0-alpha2

    • Add ProofAdd and use it in Range::join, Range::join_cover
    • Make Index<'id>, Range<'id> Send + Sync
  • 0.1.0-alpha1

    • First release

License

Dual-licensed to be compatible with the Rust project.

Licensed under the Apache License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 or the MIT license http://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms.