From cb7bcfad4ab0041aaf3fde3185e27ee46bb37788 Mon Sep 17 00:00:00 2001 From: JSDurand Date: Tue, 15 Nov 2022 12:01:28 +0800 Subject: Initial commit Basic GNU standard files are added, and we now stop worrying about monadic anamorphisms. The current focus is on testing the correctness of the algorithm, so I need convenient support for manipulating, interpreting, examining, and per chance animating nondeterministic automata. --- receme/src/ralgebra.rs | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 receme/src/ralgebra.rs (limited to 'receme/src/ralgebra.rs') diff --git a/receme/src/ralgebra.rs b/receme/src/ralgebra.rs new file mode 100644 index 0000000..989089e --- /dev/null +++ b/receme/src/ralgebra.rs @@ -0,0 +1,25 @@ +//! This file defines the behaviours of R-algebras. +//! +//! For a functor F, an R-algebra is a natural transformation from F1 +//! to the identity functor, where F1 is the functor that sends T to +//! F((F(T), T)). This extra F(T) represents the context during the +//! computations. + +use crate::functor::Functor; + +/// An R-algebra is a function from F((F(T), T)) to T. +/// +/// This is a "trait alias". Since Rust does not support trait alias +/// yet, we define an empty trait with an automatic implementation. +pub trait RAlgebra: FnMut((T, F)) -> T +where + F: Functor, +{ +} + +impl RAlgebra for R +where + F: Functor, + R: FnMut((T, F)) -> T, +{ +} -- cgit v1.2.3-18-g5258