Unification works with bad annotations

schala-lang/language/src/builtin.rs

@@ -1,6 +1,5 @@
 use std::rc::Rc;
 use std::collections::HashMap;
-use std::fmt;
 
 use crate::tokenizing::TokenKind;
 use crate::typechecking::{TypeConst, Type};

schala-lang/language/src/typechecking.rs

@@ -28,7 +28,7 @@ pub enum Type {
   Arrow(Box<Type>, Box<Type>)
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum TypeConst {
   Unit,
   Nat,
@@ -224,7 +224,10 @@ impl<'a> TypeContext<'a> {
 
 
   fn unify(&mut self, t1: Type, t2: Type) -> InferResult<Type> {
-    println!("Unify ain't done yo");
-    Ok(t1)
+    use self::Type::*; use self::TypeConst::*;
+    Ok(match (t1, t2) {
+      (Const(ref c1), Const(ref c2)) if c1 == c2 => Const(c1.clone()), //choice of c1 is arbitrary I *think*
+      (a, b) => return TypeError::new(&format!("{:?} and {:?} do not unify", a, b)),
+    })
   }
 }