1 files changed, 8 insertions, 0 deletions
diff --git a/src/sexp/util.rs b/src/sexp/util.rs
index 3de45d4..aa7ae18 100644
--- a/src/sexp/util.rs
+++ b/src/sexp/util.rs
@@ -94,4 +94,12 @@ impl SExp {
 	    _ => None,
 	}
     }
+
+    pub fn back_to_case(scrutinee: SExp, arms: Vec<SExp>) -> SExp {
+	let mut res = Atom(Nil);
+	for arm in arms.into_iter().rev() {
+	    res = scons(arm, res);
+	}
+	scons(Case, scons(scrutinee, res))
+    }
 }