1 files changed, 36 insertions, 1 deletions
diff --git a/rust/src/ast.rs b/rust/src/ast.rs
index e70f323..29d548f 100644
--- a/rust/src/ast.rs
+++ b/rust/src/ast.rs
@@ -22,7 +22,13 @@ impl Display for Value {
             Value::Num(i) => write!(f, "{}", i),
             Value::Bool(b) => write!(f, "{}", b),
             Value::Sym(s) => write!(f, "{}", s),
-            Value::App(l, r) => write!(f, "({} {})", l, r),
+            Value::App(l, r) => {
+                if let App(l1, l2) = *l.clone() {
+                    write!(f, "({} {} {})", l1, l2, r)
+                } else {
+                    write!(f, "({} {})", l, r)
+                }
+            }
             Value::Lam(var, body) => write!(f, "(lam {} {})", var, body),
             Value::Def(var, value) => write!(f, "(def {} {})", var, value),
             Value::Let(var, value, body) => write!(f, "(let ({} {}) {})", var, value, body),
@@ -71,3 +77,32 @@ impl Arbitrary for Value {
         .boxed()
     }
 }
+
+#[cfg(test)]
+mod ast_tests {
+
+    use super::{
+        identifier,
+        Value::{self, *},
+    };
+    use proptest::collection::vec;
+    use proptest::prelude::*;
+
+    fn any_sym() -> impl Strategy<Value = Value> {
+        identifier().prop_map(Sym)
+    }
+
+    proptest! {
+
+       #[test]
+        fn display_multiple_applications_as_a_sequence(atoms in vec("[a-z]".prop_map(Sym), 2..10)) {
+            let init  = atoms.first().unwrap().clone();
+            let value = atoms.iter().skip(1).fold(init, |acc, expr| {
+              Value::App(Box::new(acc.clone()), Box::new(expr.clone()))
+            });
+            assert_eq!(value.to_string(),
+                       format!("({})",
+                               atoms.iter().map(|v| v.to_string()).collect::<Vec<String>>().join(" ")));
+      }
+    }
+}