Desugar application of more than 2 values

1 files changed, 23 insertions, 3 deletions

diff --git a/rust/src/parser.rs b/rust/src/parser.rs
index 874b893..3ac01ef 100644
--- a/rust/src/parser.rs
+++ b/rust/src/parser.rs
@@ -143,10 +143,16 @@ fn parse_let(parser: &mut Parser) -> Result<Value, String> {
 
 fn parse_application(parser: &mut Parser) -> Result<Value, String> {
     parser.expect(Token::LParen)?;
-    let left = parse_expression(parser)?;
-    let right = parse_expression(parser)?;
+    let init = parse_expression(parser)?;
+    let mut exprs = Vec::new();
+    while let Ok(expr) = parse_expression(parser) {
+        exprs.push(expr);
+    }
     parser.expect(Token::RParen)?;
-    Ok(Value::App(Box::new(left), Box::new(right)))
+    let app: Value = exprs.iter().fold(init, |acc, expr| {
+        Value::App(Box::new(acc.clone()), Box::new(expr.clone()))
+    });
+    Ok(app.to_owned())
 }
 
 fn parse_value(parser: &mut Parser) -> Result<Value, String> {
@@ -296,6 +302,20 @@ mod tests {
     }
 
     #[test]
+    fn desugar_application_of_more_than_two_values() {
+        assert_eq!(
+            vec![App(
+                Box::new(App(
+                    Box::new(App(Box::new(Sym("foo".to_string())), Box::new(Num(42)))),
+                    Box::new(Bool(true))
+                )),
+                Box::new(Sym("f".to_string()))
+            )],
+            parse("(foo 42 true f)")
+        );
+    }
+
+    #[test]
     fn parse_abstraction() {
         assert_eq!(
             vec![Lam(