Readonlycodesrow-major terrain codes, width * height of them
Readonlyheaderthe key=value lines before the grid, in the order written (border_size, usage, ...)
ReadonlyheightReadonlystartsside number -> the hexes its [side] start came from, when the grid marks them
Readonlywidth
A loaded
.map: the header keys the file declared, the gridparseTerrainalready produces, and the same start markers an inline[map] terrain=string carries.