diff --git a/functions.rs b/functions.rs
deleted file mode 100644
index 7caa80e..0000000
--- a/functions.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-use crate::common::*;
-
-pub struct Functions<'a> {
-  stack: Vec<&'a Expression<'a>>,
-}
-
-impl<'a> Iterator for Functions<'a> {
-  type Item = (&'a Token<'a>, usize);
-
-  fn next(&mut self) -> Option<Self::Item> {
-    match self.stack.pop() {
-      None
-      | Some(Expression::String { .. })
-      | Some(Expression::Backtick { .. })
-      | Some(Expression::Variable { .. }) => None,
-      Some(Expression::Call {
-        token, arguments, ..
-      }) => Some((token, arguments.len())),
-      Some(Expression::Concatination { lhs, rhs }) => {
-        self.stack.push(lhs);
-        self.stack.push(rhs);
-        self.next()
-      }
-      Some(Expression::Group { expression }) => {
-        self.stack.push(expression);
-        self.next()
-      }
-    }
-  }
-}
diff --git a/variables.rs b/variables.rs
deleted file mode 100644
index 678da00..0000000
--- a/variables.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-use crate::common::*;
-
-pub struct Variables<'a> {
-  stack: Vec<&'a Expression<'a>>,
-}
-
-impl<'a> Iterator for Variables<'a> {
-  type Item = &'a Token<'a>;
-
-  fn next(&mut self) -> Option<&'a Token<'a>> {
-    match self.stack.pop() {
-      None
-      | Some(Expression::String { .. })
-      | Some(Expression::Backtick { .. })
-      | Some(Expression::Call { .. }) => None,
-      Some(Expression::Variable { token, .. }) => Some(token),
-      Some(Expression::Concatination { lhs, rhs }) => {
-        self.stack.push(lhs);
-        self.stack.push(rhs);
-        self.next()
-      }
-      Some(Expression::Group { expression }) => {
-        self.stack.push(expression);
-        self.next()
-      }
-    }
-  }
-}