feat: introduce arrow types

1 files changed, 12 insertions, 3 deletions

diff --git a/lambda-calcul/rust/src/lambda.rs b/lambda-calcul/rust/src/lambda.rs
index c624b19..1a1a85b 100644
--- a/lambda-calcul/rust/src/lambda.rs
+++ b/lambda-calcul/rust/src/lambda.rs
@@ -149,12 +149,11 @@ pub fn generate_expression_to_type(size: u32, runner: &mut TestRunner) -> Vec<Va
         0 => {
             let n = any::<u16>().new_tree(runner).unwrap().current();
             vec![Value::Num(n.into())]
-        },
+        }
         _ => {
             let n = any::<bool>().new_tree(runner).unwrap().current();
             vec![Value::Bool(n.into())]
-        },
-
+        }
     }
 }
 
@@ -358,4 +357,14 @@ mod lambda_test {
 
         assert!(ty.is_err());
     }
+
+    #[test]
+    fn type_of_a_typed_abstraction_yields_a_function_type() {
+        let value = parse1("(tlam (x :Num) 42)");
+        let mut ctx = Environment::new();
+
+        let ty = type_of(&value, &mut ctx).unwrap();
+
+        assert_eq!(Type::Arr(Box::new(Type::Num), Box::new(Type::Num)), ty);
+    }
 }