Consume entire input in sexp parser

csexp/sexp.go

@@ -147,7 +147,12 @@ func parseList(input gigaparsec.State[byte]) (gigaparsec.Result[byte, Sexp], err
 }
 
 func Parse(data []byte) (Sexp, error) {
-	result, err := parseSexp(gigaparsec.MakeState(cursor.NewSlice(data)))
+	parser := gigaparsec.Seq2(
+		parseSexp,
+		gigaparsec.End[byte](),
+		func(s Sexp, _ struct{}) Sexp { return s },
+	)
+	result, err := parser(gigaparsec.MakeState(cursor.NewSlice(data)))
 	if err != nil {
 		return nil, fmt.Errorf("csexp.Parse: %w", err)
 	}