Fix tests and app spines representations

1 files changed, 25 insertions, 12 deletions

diff --git a/rust/src/ast.rs b/rust/src/ast.rs
index cfc0e40..d0f1d6f 100644
--- a/rust/src/ast.rs
+++ b/rust/src/ast.rs
@@ -16,18 +16,36 @@ pub enum Value {
     Let(String, Box<Value>, Box<Value>),
 }
 
+use Value::*;
+
+impl Value {
+    /// Return the spine of an application
+    fn spine(&self) -> Vec<Value> {
+        match self {
+            App(l, r) => {
+                let mut spine = l.spine();
+                spine.push(*r.clone());
+                spine
+            }
+            _ => vec![self.clone()],
+        }
+    }
+}
+
 impl Display for Value {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Value::Num(i) => write!(f, "{}", i),
             Value::Bool(b) => write!(f, "{}", b),
             Value::Sym(s) => write!(f, "{}", s),
-            Value::App(l, r) => {
-                if let App(l1, l2) = *l.clone() {
-                    write!(f, "({} {} {})", l1, l2, r)
-                } else {
-                    write!(f, "({} {})", l, r)
-                }
+            Value::App(_, _) => {
+                let app = self
+                    .spine()
+                    .iter()
+                    .map(|v| v.to_string())
+                    .collect::<Vec<String>>()
+                    .join(" ");
+                write!(f, "({})", app)
             }
             Value::Lam(var, body) => write!(f, "(lam {} {})", var, body),
             Value::Def(var, value) => write!(f, "(def {} {})", var, value),
@@ -36,8 +54,6 @@ impl Display for Value {
     }
 }
 
-use Value::*;
-
 pub const IDENTIFIER: &str = "\\pL(\\pL|\\pN)*";
 
 pub fn identifier() -> RegexGeneratorStrategy<String> {
@@ -81,10 +97,7 @@ impl Arbitrary for Value {
 #[cfg(test)]
 mod ast_tests {
 
-    use super::{
-        identifier,
-        Value::{self, *},
-    };
+    use super::Value::{self, *};
     use proptest::collection::vec;
     use proptest::prelude::*;