actually compiles and does stuff now

src/ir/upper/ty.rs

@@ -0,0 +1,53 @@
+use super::{Origin, TypeDef, TypeID};
+
+#[derive(Clone)]
+pub enum Type {
+    Concrete(TypeID),
+    Bits(u32),
+    Generic { base: TypeID, args: Vec<Type> },
+    Fn { args: Vec<Type>, ret: Box<Type> },
+    Ref(Box<Type>),
+    Array(Box<Type>),
+    Infer,
+    Error,
+}
+
+impl Type {
+    pub fn rf(self) -> Self {
+        Self::Ref(Box::new(self))
+    }
+    pub fn arr(self) -> Self {
+        Self::Array(Box::new(self))
+    }
+}
+
+#[repr(usize)]
+#[derive(Debug, Clone, Copy)]
+pub enum BuiltinType {
+    Unit,
+}
+
+impl BuiltinType {
+    pub fn enumerate() -> &'static [Self; 1] {
+        &[Self::Unit]
+    }
+    pub fn def(&self) -> TypeDef {
+        match self {
+            BuiltinType::Unit => TypeDef {
+                name: "()".to_string(),
+                args: 0,
+                origin: Origin::Builtin,
+            },
+        }
+    }
+    pub fn id(&self) -> TypeID {
+        TypeID::builtin(self)
+    }
+}
+
+impl TypeID {
+    pub fn builtin(ty: &BuiltinType) -> Self {
+        Self(*ty as usize)
+    }
+}
+