TILE_MODIFIERS:Set<string> = new Set(['...', // This one isn't a modifier but we do not allow it so that we match ellipsis rules in a different rule'AGAIN', // This is another hack. Some people write `[]->[AGAIN]` rather than `[]->[]AGAIN`'DEBUGGER', // Another hack. Ensure that this is not accidentally used as a tile name'NO','LEFT','RIGHT','UP','DOWN','RANDOMDIR','RANDOM','STATIONARY','MOVING','ACTION','VERTICAL','HORIZONTAL','PERPENDICULAR','PARALLEL','ORTHOGONAL','^','<','>','V',])