From 5ad6af8f8b73cb983da20ed3a5763a7f77ee9dbc Mon Sep 17 00:00:00 2001
From: colin <colin@uninsane.org>
Date: Wed, 20 Jul 2022 02:47:15 -0700
Subject: [PATCH] coremem_types: add Peano numbers

not used yet, but will be by list/enum operations
---
 crates/types/src/compound/mod.rs   |  1 +
 crates/types/src/compound/peano.rs | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 crates/types/src/compound/peano.rs

diff --git a/crates/types/src/compound/mod.rs b/crates/types/src/compound/mod.rs
index d17e233..56578a2 100644
--- a/crates/types/src/compound/mod.rs
+++ b/crates/types/src/compound/mod.rs
@@ -1 +1,2 @@
 pub mod list;
+pub mod peano;
diff --git a/crates/types/src/compound/peano.rs b/crates/types/src/compound/peano.rs
new file mode 100644
index 0000000..83a199e
--- /dev/null
+++ b/crates/types/src/compound/peano.rs
@@ -0,0 +1,15 @@
+pub struct PNext<P>(P);
+pub struct P0;
+pub type P1 = PNext<P0>;
+
+pub trait Peano { }
+
+pub trait PeanoNonZero {
+    type Prev: Peano;
+}
+
+impl Peano for P0 { }
+impl<P: Peano> Peano for PNext<P> {}
+impl<P: Peano> PeanoNonZero for PNext<P> {
+    type Prev = P;
+}