feat: rename S to EnglishDraughtsBitSquare

loks0n · Mar 30, 2023 · d5d713f · d5d713f
1 parent c99afc2
commit d5d713f
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Showing 5 changed files with 161 additions and 36 deletions.
diff --git a/src/english/engine.test.ts b/src/english/engine.test.ts
@@ -5,7 +5,24 @@ import {
   EnglishDraughtsEngineFactory as EngineFactory,
   EnglishDraughtsEngine,
 } from './engine';
-import { S } from './utils';
+import { EnglishDraughtsBitSquare as S } from './utils';
+
+/* We use the following bitboard layout for English Draughts
+ *
+ *   11  05  31  25
+ * 10  04  30  24
+ *   03  29  23  17
+ * 02  28  22  16
+ *   27  21  15  09
+ * 26  20  14  08
+ *   19  13  07  01
+ * 18  12  06  00
+ *
+ * Access the uint32 value of a square with S[n]
+ *
+ * A move forward to the left is a rotate left 7 bits.
+ * A move forward to the right is a rotate left 1 bit.
+ */
 
 describe('possible openings', () => {
   let engine: EnglishDraughtsEngine;
@@ -17,18 +34,50 @@ describe('possible openings', () => {
   test('correct dark moves', () => {
     assert.equal(engine.data.player, DraughtsPlayer.DARK);
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[3], destination: S[2], captures: 0 },
-      { origin: S[3], destination: S[28], captures: 0 },
-      { origin: S[29], destination: S[28], captures: 0 },
-      { origin: S[29], destination: S[22], captures: 0 },
-      { origin: S[23], destination: S[22], captures: 0 },
-      { origin: S[23], destination: S[16], captures: 0 },
-      { origin: S[17], destination: S[16], captures: 0 },
+      {
+        origin: S[3],
+        destination: S[2],
+        captures: 0,
+      },
+      {
+        origin: S[3],
+        destination: S[28],
+        captures: 0,
+      },
+      {
+        origin: S[29],
+        destination: S[28],
+        captures: 0,
+      },
+      {
+        origin: S[29],
+        destination: S[22],
+        captures: 0,
+      },
+      {
+        origin: S[23],
+        destination: S[22],
+        captures: 0,
+      },
+      {
+        origin: S[23],
+        destination: S[16],
+        captures: 0,
+      },
+      {
+        origin: S[17],
+        destination: S[16],
+        captures: 0,
+      },
     ]);
   });
 
   test('correct board after move', () => {
-    engine.move({ origin: S[3], destination: S[2], captures: 0 });
+    engine.move({
+      origin: S[3],
+      destination: S[2],
+      captures: 0,
+    });
     assert.equal(engine.data.player, DraughtsPlayer.LIGHT);
     assert.equal(
       engine.data.board.dark,
@@ -49,16 +98,48 @@ describe('possible openings', () => {
   });
 
   test('correct light moves', () => {
-    engine.move({ origin: S[3], destination: S[2], captures: 0 });
+    engine.move({
+      origin: S[3],
+      destination: S[2],
+      captures: 0,
+    });
     assert.equal(engine.data.player, DraughtsPlayer.LIGHT);
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[26], destination: S[27], captures: 0 },
-      { origin: S[20], destination: S[27], captures: 0 },
-      { origin: S[20], destination: S[21], captures: 0 },
-      { origin: S[14], destination: S[21], captures: 0 },
-      { origin: S[14], destination: S[15], captures: 0 },
-      { origin: S[8], destination: S[15], captures: 0 },
-      { origin: S[8], destination: S[9], captures: 0 },
+      {
+        origin: S[26],
+        destination: S[27],
+        captures: 0,
+      },
+      {
+        origin: S[20],
+        destination: S[27],
+        captures: 0,
+      },
+      {
+        origin: S[20],
+        destination: S[21],
+        captures: 0,
+      },
+      {
+        origin: S[14],
+        destination: S[21],
+        captures: 0,
+      },
+      {
+        origin: S[14],
+        destination: S[15],
+        captures: 0,
+      },
+      {
+        origin: S[8],
+        destination: S[15],
+        captures: 0,
+      },
+      {
+        origin: S[8],
+        destination: S[9],
+        captures: 0,
+      },
     ]);
   });
 });
@@ -68,19 +149,35 @@ describe('simple move', () => {
 
   beforeEach(() => {
     engine = EngineFactory.setup({
-      board: { light: S[21] | S[0], dark: S[24], king: 0 },
+      board: {
+        light: S[21] | S[0],
+        dark: S[24],
+        king: 0,
+      },
     });
   });
 
   test('correct moves', () => {
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[24], destination: S[23], captures: 0 },
-      { origin: S[24], destination: S[17], captures: 0 },
+      {
+        origin: S[24],
+        destination: S[23],
+        captures: 0,
+      },
+      {
+        origin: S[24],
+        destination: S[17],
+        captures: 0,
+      },
     ]);
   });
 
   test('correct board after move', () => {
-    engine.move({ origin: S[24], destination: S[23], captures: 0 });
+    engine.move({
+      origin: S[24],
+      destination: S[23],
+      captures: 0,
+    });
     assert.equal(engine.data.board.light, S[21] | S[0]);
     assert.equal(engine.data.board.dark, S[23]);
     assert.equal(engine.data.board.king, 0);
@@ -92,15 +189,27 @@ describe('tricky move', () => {
 
   beforeEach(() => {
     engine = EngineFactory.setup({
-      board: { light: S[30], dark: S[21], king: 0 },
+      board: {
+        light: S[30],
+        dark: S[21],
+        king: 0,
+      },
       player: DraughtsPlayer.LIGHT,
     });
   });
 
   test('correct moves', () => {
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[30], destination: S[31], captures: 0 },
-      { origin: S[30], destination: S[5], captures: 0 },
+      {
+        origin: S[30],
+        destination: S[31],
+        captures: 0,
+      },
+      {
+        origin: S[30],
+        destination: S[5],
+        captures: 0,
+      },
     ]);
   });
 });
@@ -110,13 +219,21 @@ describe('simple jump', () => {
 
   beforeEach(() => {
     engine = EngineFactory.setup({
-      board: { light: S[21] | S[0], dark: S[22], king: 0 },
+      board: {
+        light: S[21] | S[0],
+        dark: S[22],
+        king: 0,
+      },
     });
   });
 
   test('correct moves', () => {
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[22], destination: S[20], captures: S[21] },
+      {
+        origin: S[22],
+        destination: S[20],
+        captures: S[21],
+      },
     ]);
   });
 });
@@ -126,14 +243,22 @@ describe('jump and become king', () => {
 
   beforeEach(() => {
     engine = EngineFactory.setup({
-      board: { light: S[17], dark: S[24] | S[14], king: 0 },
+      board: {
+        light: S[17],
+        dark: S[24] | S[14],
+        king: 0,
+      },
       player: DraughtsPlayer.LIGHT,
     });
   });
 
   test('correct moves', () => {
     assert.sameDeepMembers(engine.moves, [
-      { origin: S[17], destination: S[31], captures: S[24] },
+      {
+        origin: S[17],
+        destination: S[31],
+        captures: S[24],
+      },
     ]);
   });
 });
diff --git a/src/english/game.ts b/src/english/game.ts
@@ -16,7 +16,7 @@ import {
   EnglishDraughtsEngineStore,
 } from './engine';
 
-import { S, decomposeBits } from './utils';
+import { EnglishDraughtsBitSquare as S, decomposeBits } from './utils';
 
 const ENGLISH_DRAUGHTS_LAYOUT = [
   S[11],

diff --git a/src/english/index.ts b/src/english/index.ts
@@ -1,5 +1,5 @@
 export { EnglishDraughts, type EnglishDraughtsGame } from './game';
-export { S } from './utils';
+export { EnglishDraughtsBitSquare } from './utils';
 export {
   EnglishDraughtsComputerFactory,
   type EnglishDraughtsComputer,

diff --git a/src/english/mask.ts b/src/english/mask.ts
@@ -1,4 +1,4 @@
-import { S } from './utils';
+import { EnglishDraughtsBitSquare as S } from './utils';
 
 /* We use the following bitboard layout for English Draughts
  *
@@ -11,7 +11,7 @@ import { S } from './utils';
  *   19  13  07  01
  * 18  12  06  00
  *
- * Access the value of a square with S[n]
+ * Access the uint32 value of a square with S[n]
  *
  * A move forward to the left is a rotate left 7 bits.
  * A move forward to the right is a rotate left 1 bit.

diff --git a/src/english/utils.ts b/src/english/utils.ts
@@ -1,11 +1,11 @@
 const BITS = 32;
 
-const S: Record<number, number> = [];
-S[0] = 1;
+const EnglishDraughtsBitSquare: Record<number, number> = [];
+EnglishDraughtsBitSquare[0] = 1;
 for (let index = 1; index < BITS; index++) {
-  S[index] = S[index - 1] * 2;
+  EnglishDraughtsBitSquare[index] = EnglishDraughtsBitSquare[index - 1] * 2;
 }
-export { S };
+export { EnglishDraughtsBitSquare };
 
 const BIT_MASK = 0xff_ff_ff_ff;