Free Hero Mesh

  is repeated until it no longer matches. If the first word is begin,
  then it must match at least once; if it is if, then it can match zero
  or more times. The match is greedy; it will match as much as possible.

begin
  Begin a block.

Bishop
  Try four directions (NE, NW, SW, and SE).

Climb
  Fail the match if the origin object cannot climb here.

(Climb <number>)
  Fail the match if the height here is greater than this number.

cut
  Discards the most recent choice point.

else
  Delimits alternatives within a block.

Four
  Try four directions (E, N, W, and S).

Eight
  Try all eight directions.

Height
  Fail the match if the origin object can climb here.

(Height <number>)
  Fail the match if the height here isn't greater than this number.

if

ObjBottomAt
  Match the object at the bottom of this location.

ObjTopAt
  Match the object at the top of this location.

Queen
  Try all eight directions.

Rook
  Try four directions (E, N, W, and S).

then
  Ends a block started with begin or if.

Trace
  Used for debugging.