--- a/libinterp/parse-tree/lex.h
+++ b/libinterp/parse-tree/lex.h
@@ -73,7 +73,8 @@
       {
         BRACKET = 1,
         BRACE = 2,
-        PAREN = 3
+        PAREN = 3,
+        ANON_FCN_BODY = 4
       };
 
   public:
@@ -119,6 +120,13 @@
       return ! context.empty () && context.top () == PAREN;
     }
 
+    void anon_fcn_body (void) { context.push (ANON_FCN_BODY); }
+
+    bool is_anon_fcn_body (void)
+    {
+      return ! context.empty () && context.top () == ANON_FCN_BODY;
+    }
+
     bool is_bracket_or_brace (void)
     {
       return (! context.empty ()
@@ -385,8 +393,8 @@
   // set of identifiers that might be local variable names.
   std::set<std::string> pending_local_variables;
 
-  // is the closest nesting level a square bracket, squiggly brace or
-  // a paren?
+  // is the closest nesting level a square bracket, squiggly brace,
+  // a paren, or an anonymous function body?
   bbp_nesting_level nesting_level;
 
   // Tokens generated by the lexer.