Custom lexers can now terminate operators

New constraint: custom lexer output is dropped whenever it is used to terminate an operator nested inside another custom lexer, because the recursive call has to return exactly one lexeme

orchid-base/src/lib.rs

@@ -28,6 +28,6 @@ pub mod reqnot;
 pub mod sequence;
 pub mod side;
 pub mod stash;
-mod tl_cache;
+pub mod tl_cache;
 pub mod tokens;
 pub mod tree;