More return types. Basic example

examples/basic.php

@@ -0,0 +1,38 @@
+<?php
+
+require_once("vendor/autoload.php");
+
+use DNW\Skills\TrueSkill\TwoPlayerTrueSkillCalculator;
+use DNW\Skills\GameInfo;
+use DNW\Skills\Player;
+use DNW\Skills\Team;
+use DNW\Skills\Teams;
+
+$gameInfo = new GameInfo();
+
+$p1 = new Player("Winner");
+$p2 = new Player("Average");
+$p3 = new Player("Looser");
+
+
+$team1 = new Team($p1, $gameInfo->getDefaultRating());
+
+$team2 = new Team($p2, $gameInfo->getDefaultRating());
+
+for($i = 0; $i < 5; $i++) {
+    echo "Iteration: $i\n";
+    $teams = Teams::concat($team1, $team2);
+
+    $calculator = new TwoPlayerTrueSkillCalculator();
+
+    $newRatings = $calculator->calculateNewRatings($gameInfo, $teams, [1, 2]);
+
+    $team1 = new Team($p1, $newRatings->getRating($p1));
+    $team2 = new Team($p2, $newRatings->getRating($p2));
+
+    echo "P1: ". $newRatings->getRating($p1)->getConservativeRating() . PHP_EOL;
+    echo "P2: ". $newRatings->getRating($p2)->getConservativeRating() . PHP_EOL;
+}
+
+
+

src/FactorGraphs/Factor.php

@@ -10,7 +10,7 @@ abstract class Factor implements \Stringable
 {
     private array $messages = [];
 
-    private $messageToVariableBinding;
+    private HashMap $messageToVariableBinding;
 
     private string $name;
 

src/FactorGraphs/FactorGraph.php

@@ -4,14 +4,14 @@ namespace DNW\Skills\FactorGraphs;
 
 class FactorGraph
 {
-    private $variableFactory;
+    private VariableFactory $variableFactory;
 
-    public function getVariableFactory()
+    public function getVariableFactory(): VariableFactory
     {
         return $this->variableFactory;
     }
 
-    public function setVariableFactory(VariableFactory $factory)
+    public function setVariableFactory(VariableFactory $factory): void
     {
         $this->variableFactory = $factory;
     }

src/FactorGraphs/Schedule.php

@@ -4,7 +4,7 @@ namespace DNW\Skills\FactorGraphs;
 
 abstract class Schedule implements \Stringable
 {
-    protected function __construct(private $_name)
+    protected function __construct(private string $name)
     {
     }
 
@@ -12,6 +12,6 @@ abstract class Schedule implements \Stringable
 
     public function __toString(): string
     {
-        return (string) $this->_name;
+        return (string) $this->name;
     }
 }

src/GameInfo.php

@@ -18,41 +18,41 @@ class GameInfo
     private const DEFAULT_INITIAL_STANDARD_DEVIATION = 8.3333333333333333333333333333333;
 
     public function __construct(
-        private $_initialMean = self::DEFAULT_INITIAL_MEAN,
+        private float $initialMean = self::DEFAULT_INITIAL_MEAN,
-        private $_initialStandardDeviation = self::DEFAULT_INITIAL_STANDARD_DEVIATION,
+        private float $initialStandardDeviation = self::DEFAULT_INITIAL_STANDARD_DEVIATION,
-        private $_beta = self::DEFAULT_BETA,
+        private float $beta = self::DEFAULT_BETA,
-        private $_dynamicsFactor = self::DEFAULT_DYNAMICS_FACTOR,
+        private float $dynamicsFactor = self::DEFAULT_DYNAMICS_FACTOR,
-        private $_drawProbability = self::DEFAULT_DRAW_PROBABILITY
+        private float $drawProbability = self::DEFAULT_DRAW_PROBABILITY
     ) {
     }
 
     public function getInitialMean()
     {
-        return $this->_initialMean;
+        return $this->initialMean;
     }
 
     public function getInitialStandardDeviation()
     {
-        return $this->_initialStandardDeviation;
+        return $this->initialStandardDeviation;
     }
 
     public function getBeta()
     {
-        return $this->_beta;
+        return $this->beta;
     }
 
     public function getDynamicsFactor()
     {
-        return $this->_dynamicsFactor;
+        return $this->dynamicsFactor;
     }
 
     public function getDrawProbability()
     {
-        return $this->_drawProbability;
+        return $this->drawProbability;
     }
 
     public function getDefaultRating()
     {
-        return new Rating($this->_initialMean, $this->_initialStandardDeviation);
+        return new Rating($this->initialMean, $this->initialStandardDeviation);
     }
 }

src/Rating.php

@@ -16,14 +16,14 @@ class Rating implements \Stringable
      * @param float     $_standardDeviation                       The standard deviation of the rating (also known as s).
      * @param float|int $_conservativeStandardDeviationMultiplier optional The number of standardDeviations to subtract from the mean to achieve a conservative rating.
      */
-    public function __construct(private $_mean, private $_standardDeviation, private $_conservativeStandardDeviationMultiplier = self::CONSERVATIVE_STANDARD_DEVIATION_MULTIPLIER)
+    public function __construct(private float $_mean, private float $_standardDeviation, private float|int $_conservativeStandardDeviationMultiplier = self::CONSERVATIVE_STANDARD_DEVIATION_MULTIPLIER)
     {
     }
 
     /**
-     * The statistical mean value of the rating (also known as <EFBFBD>).
+     * The statistical mean value of the rating (also known as mu).
      */
-    public function getMean()
+    public function getMean(): float
     {
         return $this->_mean;
     }
@@ -31,7 +31,7 @@ class Rating implements \Stringable
     /**
      * The standard deviation (the spread) of the rating. This is also known as s.
      */
-    public function getStandardDeviation()
+    public function getStandardDeviation(): float
     {
         return $this->_standardDeviation;
     }
@@ -39,12 +39,12 @@ class Rating implements \Stringable
     /**
      * A conservative estimate of skill based on the mean and standard deviation.
      */
-    public function getConservativeRating()
+    public function getConservativeRating(): float
     {
         return $this->_mean - $this->_conservativeStandardDeviationMultiplier * $this->_standardDeviation;
     }
 
-    public function getPartialUpdate(Rating $prior, Rating $fullPosterior, $updatePercentage)
+    public function getPartialUpdate(Rating $prior, Rating $fullPosterior, $updatePercentage): Rating
     {
         $priorGaussian = new GaussianDistribution($prior->getMean(), $prior->getStandardDeviation());
         $posteriorGaussian = new GaussianDistribution($fullPosterior->getMean(), $fullPosterior . getStandardDeviation());
@@ -56,7 +56,7 @@ class Rating implements \Stringable
         $precisionDifference = $posteriorGaussian->getPrecision() - $priorGaussian->getPrecision();
         $partialPrecisionDifference = $updatePercentage * $precisionDifference;
 
-        $precisionMeanDifference = $posteriorGaussian->getPrecisionMean() - $priorGaussian . getPrecisionMean();
+        $precisionMeanDifference = $posteriorGaussian->getPrecisionMean() - $priorGaussian->getPrecisionMean();
         $partialPrecisionMeanDifference = $updatePercentage * $precisionMeanDifference;
 
         $partialPosteriorGaussion = GaussianDistribution::fromPrecisionMean(

src/RatingContainer.php

@@ -11,7 +11,7 @@ class RatingContainer
         $this->playerToRating = new HashMap();
     }
 
-    public function getRating(Player $player): mixed
+    public function getRating(Player $player): Rating
     {
         return $this->playerToRating->getValue($player);
     }

src/TrueSkill/Factors/GaussianPriorFactor.php

@@ -13,7 +13,7 @@ use DNW\Skills\Numerics\GaussianDistribution;
  */
 class GaussianPriorFactor extends GaussianFactor
 {
-    private $newMessage;
+    private GaussianDistribution $newMessage;
 
     public function __construct(float $mean, float $variance, Variable $variable)
     {

src/TrueSkill/Factors/GaussianWeightedSumFactor.php

@@ -11,7 +11,7 @@ use DNW\Skills\Numerics\GaussianDistribution;
 /**
  * Factor that sums together multiple Gaussians.
  *
- * See the accompanying math paper for more details.s
+ * See the accompanying math paper for more details.
  */
 class GaussianWeightedSumFactor extends GaussianFactor
 {
@@ -213,7 +213,7 @@ class GaussianWeightedSumFactor extends GaussianFactor
         );
     }
 
-    private static function createName($sumVariable, $variablesToSum, $weights)
+    private static function createName(string $sumVariable, array $variablesToSum, array $weights): string
     {
         // TODO: Perf? Use PHP equivalent of StringBuilder? implode on arrays?
         $result = (string) $sumVariable;

src/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php

@@ -10,7 +10,7 @@ use DNW\Skills\FactorGraphs\ScheduleSequence;
 
 class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
 {
-    public function buildLayer()
+    public function buildLayer(): void
     {
         $inputVariablesGroups = $this->getInputVariablesGroups();
         $outputVariablesGroups = &$this->getOutputVariablesGroups();

src/TrueSkill/Layers/TeamDifferencesComparisonLayer.php

@@ -9,7 +9,7 @@ use DNW\Skills\TrueSkill\TrueSkillFactorGraph;
 
 class TeamDifferencesComparisonLayer extends TrueSkillFactorGraphLayer
 {
-    private $epsilon;
+    private float $epsilon;
 
     public function __construct(TrueSkillFactorGraph $parentGraph, private readonly array $teamRanks)
     {
@@ -18,7 +18,7 @@ class TeamDifferencesComparisonLayer extends TrueSkillFactorGraphLayer
         $this->epsilon = DrawMargin::getDrawMarginFromDrawProbability($gameInfo->getDrawProbability(), $gameInfo->getBeta());
     }
 
-    public function buildLayer()
+    public function buildLayer(): void
     {
         $inputVarGroups = $this->getInputVariablesGroups();
         $inputVarGroupsCount = is_countable($inputVarGroups) ? count($inputVarGroups) : 0;

src/TrueSkill/TwoPlayerTrueSkillCalculator.php

@@ -78,7 +78,7 @@ class TwoPlayerTrueSkillCalculator extends SkillCalculator
         return $results;
     }
 
-    private static function calculateNewRating(GameInfo $gameInfo, Rating $selfRating, Rating $opponentRating, $comparison)
+    private static function calculateNewRating(GameInfo $gameInfo, Rating $selfRating, Rating $opponentRating, $comparison): Rating
     {
         $drawMargin = DrawMargin::getDrawMarginFromDrawProbability(
             $gameInfo->getDrawProbability(),