+typesys crate

Cargo.lock

@@ -161,6 +161,10 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "wafl-typesys"
+version = "0.1.0"
+
 [[package]]
 name = "windows-sys"
 version = "0.45.0"

crates/wafl-typesys/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "wafl-typesys"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

crates/wafl-typesys/src/lib.rs

@@ -0,0 +1,33 @@
+use core::fmt;
+use std::collections::BTreeMap;
+use std::sync::Arc;
+
+#[derive(Clone, Debug)]
+pub enum Type {
+    Top,
+    Bot,
+    Primitive(PrimitiveType),
+    Union(Vec<Type>),
+    Inter(Vec<Type>),
+    Function(Box<(Type, Type)>),
+    Recursive(Arc<TypeVariable>, Box<Type>),
+    Variable(Arc<TypeVariable>),
+    Record(BTreeMap<String, Type>),
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum PrimitiveType {
+    Integer,
+}
+
+#[derive(Debug)]
+pub struct TypeVariable {
+    pub name_hint: String,
+    pub hash_: u32,
+}
+
+impl fmt::Display for TypeVariable {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{:x}", self.name_hint, self.hash_)
+    }
+}