fix single terminal grammars

controllers/ag2_ctrl/run_g.py

@@ -216,10 +216,17 @@ def character_maker2(lm, id, description, valid_weapons):
     grm = string("this is a test")
 
     prompt = "How much is 2 + 2? "
-    grm = gen(name="test", max_tokens=30, regex=r"\d+")
+    grm = gen(name="test", max_tokens=30, regex=r"[0-9]+", stop=".")
 
     prompt = "Three things about J. Random Hacker:\n"
-    grm = gen_json_object("hacker", max_tokens=150) + "\nScore (0-9): " + gen("score", regex=r"[0-9]")
+    grm = (
+        gen_json_object("hacker", max_tokens=150)
+        + "\nScore (0-9): "
+        + gen("score", regex=r"[0-9]")
+    )
+
+    prompt = "A number: "
+    grm = gen_grammar("", greedy_grammar(lexeme(r"[0-9]{3}")))
 
     # grm = "Q: 7 * 8\nA: " + gen("text", regex="[0-9]+", max_tokens=20) + "\n"
 

controllers/ag2_ctrl/src/earley/grammar.rs

@@ -300,6 +300,13 @@ impl Grammar {
         }
 
         let mut outp = Grammar::new();
+
+        let start_data = self.sym_data(self.start());
+        if start_data.is_terminal() {
+            let new_start = outp.fresh_symbol("_start_repl");
+            outp.add_rule(new_start, vec![SymIdx(1)]).unwrap();
+        }
+
         for sym in &self.symbols {
             if repl.contains_key(&sym.idx) {
                 continue;

controllers/ag2_ctrl/src/earley/lexerspec.rs

@@ -63,7 +63,7 @@ impl Debug for LexemeSpec {
             write!(f, " eos-only")?;
         }
         if self.contextual {
-            write!(f, " allow-others")?;
+            write!(f, " contextual")?;
         }
         Ok(())
     }