Several functions exist which can test the position of
a tile with respect to another.
Northof(tile1,tile2)
Southof(tile1,tile2)
Westof(tile1,tile2)
Eastof(tile1,tile2)
These return true if tile1 is in that direction from
tile2. Switch to the world All Here and try these
sentences, which are all true:
Northof(e,f)
Southof(a,b)
Westof(c,f)
Eastof(f,e)
SameRow(tile1,tile2) and
SameCol(tile1,tile2)
return true if the two tiles are on the same row or
column. Switch to the world All Here Revisted and try
these sentences:
SameRow(c,f)
SameCol(a,b)
SameCol(a,b) and SameRow(b,d)
The Between(tile1,tile2,tile3) function returns
true if tile1 lies discretely between tile2 and
tile3. This means that the centers of the cells containing these
3 tiles must lie on a straight line and tile1 is the middle tile
of the three.
For example, in the Blocks Abundant world, all these are true:
Between(g,a,f)
Between(g,f,a)
Between(j,a,h)
Between(b,a,c)
Between(c,g,d)
Between(e,h,i)
Between(d,a,e)
but these are false:
Between(a,g,f)
Between(b,a,g)
Between(b,a,i)
Between(d,j,i)
If-then Tests
Index