diff --git a/src/parser/nodes/constant.rs b/src/parser/nodes/constant.rs
new file mode 100644
index 0000000..cd40049
--- /dev/null
+++ b/src/parser/nodes/constant.rs
@@ -0,0 +1,24 @@
+/* parser/nodes/constant.rs
+ * Eryn Wells <eryn@erynwells.me>
+ */
+
+use std::fmt;
+use types::{Boolean, Number};
+use super::TreeDebug;
+
+pub trait ConstantValue {}
+impl ConstantValue for Boolean {}
+impl ConstantValue for Number {}
+
+#[derive(Debug)]
+pub struct Constant<V: ConstantValue> {
+    value: V
+}
+
+impl<V: ConstantValue + fmt::Debug> TreeDebug for Constant<V> {}
+
+impl<V: ConstantValue> Constant<V> {
+    pub fn new(value: V) -> Constant<V> {
+        Constant { value: value }
+    }
+}
diff --git a/src/parser/nodes/mod.rs b/src/parser/nodes/mod.rs
index ad2ba69..28a824d 100644
--- a/src/parser/nodes/mod.rs
+++ b/src/parser/nodes/mod.rs
@@ -2,6 +2,23 @@
  * Eryn Wells <eryn@erynwells.me>
  */
 
+use std::fmt;
+
 pub use self::constant::Constant;
 
 mod constant;
+mod program;
+
+trait TreeDebug: fmt::Debug {
+    fn tree_indent(indent: u8) -> String {
+        (0..10).fold(String::new(), |mut acc, i| {
+            acc.push(' ');
+            acc
+        })
+    }
+
+    fn tree_fmt(&self, f: &mut fmt::Formatter, indent: u8) -> fmt::Result {
+        write!(f, "{}{:?}", self.tree_indent(indent), self)
+    }
+}
+
diff --git a/src/parser/nodes/program.rs b/src/parser/nodes/program.rs
new file mode 100644
index 0000000..0c47ce0
--- /dev/null
+++ b/src/parser/nodes/program.rs
@@ -0,0 +1,26 @@
+/* parser/nodes/program.rs
+ * Eryn Wells <eyrn@erynwells.me>
+ */
+
+use std::fmt;
+
+use super::TreeDebug;
+use super::Constant;
+
+pub struct Program {
+    forms: Vec<Constant>,
+}
+
+impl TreeDebug for Program {
+    fn tree_fmt(&self, f: fmt::Formatter, indent: u8) -> fmt::Result {
+        let spaces = self.tree_indent(indent);
+        let mut result = write!(f, "{}Program", spaces);
+        for form in self.forms {
+            if result.is_err() {
+                break;
+            }
+            result = form.tree_fmt(f, indent + 2);
+        }
+        result
+    }
+}