[−][src]Crate pergola

This is a small crate that provides a generic unital-join-semilattice type

(hereafter: "lattice") along with a few common instances.
Lattices are defined in two separate pieces: a definition trait
LatticeDef that provides the type-and-functions for a given lattice and a
user interface struct LatticeElt that's parameterized by a LatticeDef
and provides convenient methods to work with (including impls of standard
Rust operator traits).
This unusual split exists because many types have multiple equally viable
lattices you can build on them (eg. u32-with-min or u32-with-max) and we want
to avoid both coupling any given lattice definition to the type or
accidentally inheriting an impl for any of the type's "standard semantics" as
the lattice semantics, eg. we don't want to inherit u32's standard partial
order as any lattice's partial order, unless explicitly building such a
lattice.

Structs

Write code that uses lattices over this type, and it will delegate to the functions of the parameter LatticeDef.

Traits

Implement this trait on a (typically vacuous) type to define a specific lattice as a type-with-some-choice-of-operators.