diff --git a/src/protocol/parser/tokens.rs b/src/protocol/parser/tokens.rs
index f3f61764315b9abefdef709ab89cea174e080af6..d8c6b7d25b01b89aea578664be187660c0a025bb 100644
--- a/src/protocol/parser/tokens.rs
+++ b/src/protocol/parser/tokens.rs
@@ -212,8 +212,9 @@ impl TokenBuffer {
         Self{ tokens: Vec::new(), ranges: Vec::new() }
     }
 
-    pub(crate) fn iter_range<'a>(&'a self, range: &TokenRange) -> TokenIter<'a> {
-        TokenIter::new(self, range.start as usize, range.end as usize)
+    pub(crate) fn iter_range<'a>(&'a self, inclusive_start: u32, exclusive_end: u32) -> TokenIter<'a> {
+        debug_assert!(exclusive_end as usize <= self.tokens.len());
+        TokenIter::new(self, inclusive_start as usize, exclusive_end as usize)
     }
 
     pub(crate) fn start_pos(&self, range: &TokenRange) -> InputPosition {
@@ -337,6 +338,10 @@ impl<'a> TokenIter<'a> {
         }
     }
 
+    pub(crate) fn token_index(&self) -> u32 {
+        return self.cur as u32;
+    }
+
     /// Saves the current iteration position, may be passed to `load` to return
     /// the iterator to a previous position.
     pub(crate) fn save(&self) -> (usize, usize) {