An html version of castle.cql

; castle.cql can be downloaded here.
;;This file looks for all studies in which black or white castles in the main line
;; or in a variation (or both)
;; This is done simply by looking for positions such that the current move is 
;; a move of a King from the e file to the c or g files

(match
 :pgn heijden.pgn
 :output out.pgn
 (position
  :movefrom [Kk]e?
  :moveto .[c?,g?]
  :variations ; look also in the variations
  )
)