1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
;;; chess-perft.el --- Perft tests for emacs-chess -*- lexical-binding: t; -*-
;; Copyright (C) 2014 Mario Lang
;; Author: Mario Lang <mlang@delysid.org>
;; Keywords: games
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; The classic perft function counts all leave nodes at a certain depth.
;; To make it easier to identify specific problems we also count properties
;; of the individual (final) plies. We count capturing plies, en passant plies,
;; castling plies, plies that promote to a piece,
;; plies which bring the opponent king in check and plies which result in
;; checkmate.
;; Typically depths greater than 4 will result in very long runtimes.
;; We only define tests which do not take a lot of execution time
;; (less than a million nodes).
;; To make it easier to selectively run tests, all tests provide tags
;; to indentify which type of ply they are covering.
;; The available ERT tags are:
;; :capture, :en-passant, :castle, :promotion, :check and :checkmate.
;;
;; For instance, to make sure castling plies work as expected, run
;; M-: (ert '(tag :castle)) RET
;;; Code:
(require 'chess-fen)
(require 'chess-ply)
(require 'chess-pos)
(require 'cl-lib)
(require 'ert)
(defun chess-perft (position depth)
"Count all leave nodes of the tree starting at POSITION pruned at DEPTH.
The result is a list of the form
(LEAVES CAPTURES EN-PASSANTS CASTLES PROMOTIONS CHECKS CHECKMATES)."
(if (zerop depth)
(cl-values 1 0 0 0 0)
(let ((plies (chess-legal-plies position
:color (chess-pos-side-to-move position))))
(if (= depth 1)
(cl-values (length plies)
;; Captures
(cl-count-if
(lambda (ply)
(or (chess-pos-piece-p
(chess-ply-pos ply) (chess-ply-target ply)
(not (chess-pos-side-to-move (chess-ply-pos ply))))
(let ((en-passant (chess-pos-en-passant
(chess-ply-pos ply))))
(and en-passant
(chess-pos-piece-p (chess-ply-pos ply)
en-passant
(not
(chess-pos-side-to-move
(chess-ply-pos ply))))
(/= (chess-ply-target ply) en-passant)
(/= (chess-pos-piece
(chess-ply-pos ply) en-passant)
(chess-pos-piece
(chess-ply-next-pos ply) en-passant))))))
plies)
;; En passants
(cl-count-if
(lambda (ply)
(let ((en-passant (chess-pos-en-passant
(chess-ply-pos ply))))
(and en-passant
(chess-pos-piece-p (chess-ply-pos ply)
en-passant
(not
(chess-pos-side-to-move
(chess-ply-pos ply))))
(/= (chess-ply-target ply) en-passant)
(/= (chess-pos-piece
(chess-ply-pos ply) en-passant)
(chess-pos-piece
(chess-ply-next-pos ply) en-passant)))))
plies)
;; Castles
(cl-count-if
(lambda (ply)
(chess-ply-any-keyword ply :castle :long-castle))
plies)
;; Promotions
(cl-count-if
(lambda (ply)
(chess-ply-keyword ply :promote))
plies)
;; Checks
(cl-count-if
(lambda (ply)
(chess-ply-any-keyword ply :check :checkmate))
plies)
;; Checkmates
(cl-count-if
(lambda (ply)
(chess-ply-any-keyword ply :checkmate))
plies))
(let ((nodes 0) (captures 0) (en-passants 0)
(castles 0) (promotions 0)
(checks 0) (checkmates 0))
(dolist (ply plies (cl-values nodes
captures en-passants
castles promotions
checks checkmates))
(cl-multiple-value-bind (n c e ca p ch cm)
(chess-perft (chess-ply-next-pos ply) (1- depth))
(cl-incf nodes n)
(cl-incf captures c)
(cl-incf en-passants e)
(cl-incf castles ca)
(cl-incf promotions p)
(cl-incf checks ch)
(cl-incf checkmates cm))))))))
(ert-deftest chess-perft-startpos-depth1 ()
(should (equal (chess-perft (chess-pos-create) 1) '(20 0 0 0 0 0 0))))
(ert-deftest chess-perft-startpos-depth2 ()
(should (equal (chess-perft (chess-pos-create) 2) '(400 0 0 0 0 0 0))))
(ert-deftest chess-perft-startpos-depth3 ()
:tags '(:capture :check)
(should (equal (chess-perft (chess-pos-create) 3) '(8902 34 0 0 0 12 0))))
(ert-deftest chess-perft-startpos-depth4 ()
:tags '(:capture :check :checkmate)
(should (equal (chess-perft (chess-pos-create) 4) '(197281 1576 0 0 0 469 8))))
(ert-deftest chess-perft-kiwipete-depth1 ()
:tags '(:capture :castle)
(let ((position
(chess-fen-to-pos
"r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -")))
(should (equal (chess-perft position 1) '(48 8 0 2 0 0 0)))))
(ert-deftest chess-perft-kiwipete-depth2 ()
:tags '(:capture :en-passant :castle :check)
(let ((position
(chess-fen-to-pos
"r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -")))
(should (equal (chess-perft position 2) '(2039 351 1 91 0 3 0)))))
(ert-deftest chess-perft-kiwipete-depth3 ()
"This test is expected to fail due to a (undetermined) bug in castling
generation. We do generate too many castling moves."
:tags '(:capture :en-passant :castle :check :checkmate)
(let ((position
(chess-fen-to-pos
"r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq -")))
(should (equal (chess-perft position 3) '(97862 17102 45 3162 0 993 1)))))
(ert-deftest chess-perft-pos3-depth1 ()
:tags '(:capture :check)
(let ((position (chess-fen-to-pos "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -")))
(should (equal (chess-perft position 1) '(14 1 0 0 0 2 0)))))
(ert-deftest chess-perft-pos3-depth2 ()
:tags '(:capture :check)
(let ((position (chess-fen-to-pos "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -")))
(should (equal (chess-perft position 2) '(191 14 0 0 0 10 0)))))
(ert-deftest chess-perft-pos3-depth3 ()
:tags '(:capture :en-passant :check)
(let ((position (chess-fen-to-pos "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -")))
(should (equal (chess-perft position 3) '(2812 209 2 0 0 267 0)))))
(ert-deftest chess-perft-pos3-depth4 ()
:tags '(:capture :en-passant :check :checkmate)
(let ((position (chess-fen-to-pos "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -")))
(should (equal (chess-perft position 4) '(43238 3348 123 0 0 1680 17)))))
(ert-deftest chess-perft-pos3-depth5 ()
:tags '(:capture :en-passant :check)
(let ((position (chess-fen-to-pos "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - -")))
(should (equal (chess-perft position 5) '(674624 52051 1165 0 0 52950 0)))))
(ert-deftest chess-perft-pos4-depth1 ()
(let ((chess-ply-allow-interactive-query nil)
(position
(chess-fen-to-pos
"r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq -")))
(should (equal (chess-perft position 1) '(6 0 0 0 0 0 0)))))
(ert-deftest chess-perft-pos4-depth2 ()
:tags '(:capture :castle :promotion :check)
(let ((chess-ply-allow-interactive-query nil)
(position
(chess-fen-to-pos
"r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq -")))
(should (equal (chess-perft position 2) '(264 87 0 6 48 10 0)))))
(ert-deftest chess-perft-pos4-depth3 ()
:tags '(:capture :en-passant :promotion :check :checkmate)
(let ((chess-ply-allow-interactive-query nil)
(position
(chess-fen-to-pos
"r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq -")))
(should (equal (chess-perft position 3) '(9467 1021 4 0 120 38 22)))))
(ert-deftest chess-perft-pos4-depth4 ()
:tags '(:capture :castle :promotion :check :checkmate)
(let ((chess-ply-allow-interactive-query nil)
(position
(chess-fen-to-pos
"r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq -")))
(should (equal (chess-perft position 4) '(422333 131393 0 7795 60032 15492 5)))))
(provide 'chess-perft)
;;; chess-perft.el ends here
|
