1 files changed, 23 insertions, 1 deletions
diff --git a/src/ast.rs b/src/ast.rs
index b5f2049..3863ce9 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -1,5 +1,27 @@
 #[derive(Debug)]
-pub struct Program(pub Box<Expression>);
+pub struct WithLocation<T> {
+    value: T,
+    location: (usize, usize),
+}
+
+impl<T> WithLocation<T> {
+    pub fn new(value: T, start: usize, end: usize) -> WithLocation<T> {
+        WithLocation {
+            value: value,
+            location: (start, end),
+        }
+    }
+
+    pub fn map<U, F: FnOnce(T) -> U>(self, f: F) -> WithLocation<U> {
+        WithLocation {
+            value: f(self.value),
+            location: self.location,
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct Program(pub Box<WithLocation<Expression>>);
 
 #[derive(Debug)]
 pub enum Expression {