. Topos-Oriented Programming
What topos-oriented programming means in Yon: subobject classifier, comprehension types, functors with checked laws, and an intuitionistic core, compiled to native code.
. Installation
Yon runs on Linux x86-64 and macOS arm64 (Apple Silicon). Prebuilt
. Hello, world
A Yon program is a list of top-level declarations; execution starts at main,
. Values and bindings
This program exits with 62 and prints ciao mondo. Walking through it:
. Control flow and mutation
= is the one mutation. A binding that is ever the target of = is
. Functions and effects
Inference. A parameter may omit its annotation; the signature pre-pass
. Worlds and places
Yon's data model is categorical, and the category is not an abstraction you keep
. Arrows
A restaurant runs on things that happen at different levels. The price of a dish
. The Heyting core
Yon's logic is intuitionistic. The proposition type ฮฉ is a Heyting algebra
. Types from HoTT
Yon's type system has a homotopy-type-theoretic layer: universes (Type,
0. Generics
Write a function that hands back what it was given. For a number it reads:
1. Spaces and packages
A Space is a hermetic tenant: a named heap where sections live. A Space is
2. A tour of the standard library
The stdlib is organized in modules; the full index is in the
3. The content-addressed heap
Everything you have built so far, numbers aside, lives in one structure:
4. Values, cells, and lifetime
Values have no identity
5. Data structures on the lattice
Every collection in the stdlib is a persistent structure over the
6. Projects, yon.toml, and packages
A project is a directory
7. How Spaces talk
Chapter 11 showed the surface:addtriple from Mid, and a call
8. The project: a ledger in three packages
Everything in one walkthrough: a git dependency, a service in its own Space,
9. When things go wrong
Yon has no exceptions, no unwinding, no try/catch, deliberately. A
0. Capabilities
A move can demand more than well-typed fields: it can demand authority.
1. Tooling
Beyond yonc and yon-pkg (chapters 1, 16), the toolchain ships a small set of
Keywords, one by one
Every reserved word of Yon, explained next to an example.
Appendix A. Glossary
One sentence each. Left what it means in Yon, with the
Appendix B. Future work
1.1.0 draws its perimeter on purpose. A limit you know is a contract; a limit you
Appendix C. Yon, for those coming from elsewhere
Calibrated comparisons. Where a rival is more mature, this page says so.
Appendix D. Benchmarks
Measured per-operation timings for Yon's data structures on Apple M1, with the full method: pytest-benchmark, baseline subtraction, machine and round count stated.