[elpa] 01/01: chess-algebraic-regexp: Use rx.

[Mario Lang]

mlang pushed a commit to branch externals/chess
in repository elpa.

commit 04dc0c8e7a8f2e8936b815be166bb3d41447dacb
Author: Mario Lang <address@hidden>
Date:   Tue Jun 3 13:43:06 2014 +0200

    chess-algebraic-regexp: Use rx.
---
 chess-algebraic.el |   40 ++++++++++++++++------------------------
 1 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/chess-algebraic.el b/chess-algebraic.el
index c0d4038..5b3e043 100644
--- a/chess-algebraic.el
+++ b/chess-algebraic.el
@@ -57,29 +57,21 @@
 (require 'chess-message)
 (require 'chess-pos)
 
-(defconst chess-algebraic-pieces-regexp "[RNBKQ]")
-
-;; jww (2008-09-01): use rx here, like in chess-ics
 (defconst chess-algebraic-regexp
-  (format (concat "\\("
-                   "O-O\\(-O\\)?\\|"
-                   "\\(%s?\\)/?"       ; what is the / doing here?
-                   "\\([a-h]?[1-8]?\\)"
-                   "\\([x-]?\\)"
-                   "\\([a-h][1-8]\\)"
-                   "\\(=\\(%s\\)\\)?"
-                 "\\)"
-                 "\\([#+]\\)?")
-         chess-algebraic-pieces-regexp
-         chess-algebraic-pieces-regexp)
+  (rx (group (or (or "O-O" "O-O-O")
+                (and (optional (group (char ?N ?B ?R ?Q ?K)))
+                     (optional (char ?/))
+                     (group (optional (char "a-h")) (optional (char "1-8")))
+                     (optional (group (char ?- ?x)))
+                     (group (char "a-h") (char "1-8"))
+                     (optional (group ?= (group (char ?N ?B ?R ?Q ?K)))))))
+      (optional (group (char ?+ ?#))))
   "A regular expression that matches all possible algebraic moves.
 This regexp handles both long and short form.")
 
-(defconst chess-algebraic-regexp-entire
-  (concat chess-algebraic-regexp "$"))
+(defconst chess-algebraic-regexp-entire (concat chess-algebraic-regexp "$"))
 
-(defconst chess-algebraic-regexp-ws
-  (concat chess-algebraic-regexp "\\s-"))
+(defconst chess-algebraic-regexp-ws (concat chess-algebraic-regexp "\\s-"))
 
 (chess-message-catalog 'english
   '((clarify-piece     . "Clarify piece to move by rank or file")
@@ -95,17 +87,17 @@ This regexp handles both long and short form.")
   (let ((case-fold-search nil))
     (when (string-match chess-algebraic-regexp-entire move)
       (let ((color (chess-pos-side-to-move position))
-           (mate (match-string 9 move))
+           (mate (match-string 8 move))
            (piece (aref move 0))
            changes long-style)
        (if (eq piece ?O)
            (setq changes (chess-ply-castling-changes
                           position (= (length (match-string 1 move)) 5)))
-         (let ((promotion (match-string 8 move)))
+         (let ((promotion (match-string 7 move)))
            (setq
             changes
-            (let ((source (match-string 4 move))
-                  (target (chess-coord-to-index (match-string 6 move))))
+            (let ((source (match-string 3 move))
+                  (target (chess-coord-to-index (match-string 5 move))))
               (if (and source (= (length source) 2))
                   (prog1
                       (list (chess-coord-to-index source) target)
@@ -142,8 +134,8 @@ This regexp handles both long and short form.")
                               (chess-error 'could-not-clarify)
                             (list which target))))
                     (chess-error 'no-candidates move))))))
-           (if promotion
-               (nconc changes (list :promote (aref promotion 0))))))
+           (when promotion
+             (nconc changes (list :promote (aref promotion 0))))))
 
        (when changes
          (if (and trust mate)