piece/square configurations
CQL supports a number of filters to search for patterns of squares and pieces in a specific position. These filters only consider the arrangement of pieces or squares: they do not consider side-to-move, next move, or any other dynamic features of a position. In the table below, click on the name of a filter for more detailed information:
| filter name |
example |
description |
|---|
| . |
. |
a-h1-8, i.e. any square |
| attack |
attack (R K) |
first argument attacks second argument |
| between |
between (R K) |
squares between its arguments |
| check |
check |
one side is in check |
| countsquares |
countsquares 3 8 Q |
number of squares in its argument is within range |
| darksquares |
darksquares |
dark squares |
| directional filters |
right 1 Q |
squares in specified direction in specified distance |
| lightsquares |
lightsquares |
lightsquares |
| mate |
check |
one side is mated |
| piece designators |
Na3
[RQ]a-h2-3 |
designated pieces on designated squares |
| power |
power 15 100 A |
material of argument is in range |
| powerdifference |
powerdifference 15 100 (A a) |
difference in material of arguments is in range |
| ray |
ray (Q a k) |
specified arguments arranged in ordered line segment without interference |
| stalemate |
stalemate |
one side in stalemate |