More type work.

src/TrueSkill/FactorGraphTrueSkillCalculator.php

@@ -86,7 +86,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
         return exp($expPart) * sqrt($sqrtPart);
     }
 
-    private static function getPlayerMeansVector(array $teamAssignmentsList)
+    private static function getPlayerMeansVector(array $teamAssignmentsList): Vector
     {
         // A simple vector of all the player means.
         return new Vector(
@@ -97,7 +97,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
         );
     }
 
-    private static function getPlayerCovarianceMatrix(array $teamAssignmentsList)
+    private static function getPlayerCovarianceMatrix(array $teamAssignmentsList): DiagonalMatrix
     {
         // This is a square matrix whose diagonal values represent the variance (square of standard deviation) of all
         // players.
@@ -110,7 +110,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
     }
 
     // Helper function that gets a list of values for all player ratings
-    private static function getPlayerRatingValues(array $teamAssignmentsList, $playerRatingFunction)
+    private static function getPlayerRatingValues(array $teamAssignmentsList, \Closure $playerRatingFunction): array
     {
         $playerRatingValues = [];
 

src/TrueSkill/Factors/GaussianGreaterThanFactor.php

@@ -14,16 +14,16 @@ use DNW\Skills\TrueSkill\TruncatedGaussianCorrectionFunctions;
  */
 class GaussianGreaterThanFactor extends GaussianFactor
 {
-    private $epsilon;
+    private float $epsilon;
 
-    public function __construct($epsilon, Variable $variable)
+    public function __construct(float $epsilon, Variable $variable)
     {
         parent::__construct(\sprintf('%s > %.2f', $variable, $epsilon));
         $this->epsilon = $epsilon;
         $this->createVariableToMessageBinding($variable);
     }
 
-    public function getLogNormalization()
+    public function getLogNormalization(): float
     {
         /**
  * @var Variable[] $vars
@@ -48,7 +48,7 @@ class GaussianGreaterThanFactor extends GaussianFactor
         );
     }
 
-    protected function updateMessageVariable(Message $message, Variable $variable)
+    protected function updateMessageVariable(Message $message, Variable $variable): float
     {
         $oldMarginal = clone $variable->getValue();
         $oldMessage = clone $message->getValue();

src/TrueSkill/Factors/GaussianLikelihoodFactor.php

@@ -70,7 +70,7 @@ class GaussianLikelihoodFactor extends GaussianFactor
         return GaussianDistribution::subtract($newMarginal, $marginal1);
     }
 
-    public function updateMessageIndex($messageIndex): float
+    public function updateMessageIndex(int $messageIndex): float
     {
         $messages = $this->getMessages();
         $vars = $this->getVariables();

src/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php

@@ -6,10 +6,11 @@ use DNW\Skills\FactorGraphs\ScheduleStep;
 use DNW\Skills\FactorGraphs\ScheduleSequence;
 use DNW\Skills\PartialPlay;
 use DNW\Skills\TrueSkill\Factors\GaussianWeightedSumFactor;
+use DNW\Skills\FactorGraphs\Variable; 
 
 class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLayer
 {
-    public function buildLayer()
+    public function buildLayer(): void
     {
         $inputVariablesGroups = $this->getInputVariablesGroups();
         foreach ($inputVariablesGroups as $currentTeam) {
@@ -38,7 +39,7 @@ class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLaye
         );
     }
 
-    protected function createPlayerToTeamSumFactor($teamMembers, $sumVariable): GaussianWeightedSumFactor
+    protected function createPlayerToTeamSumFactor(array $teamMembers, Variable $sumVariable): GaussianWeightedSumFactor
     {
         $weights = array_map(
             function ($v) {
@@ -75,7 +76,7 @@ class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLaye
         return $this->scheduleSequence($allFactors, "all of the team's sum iterations");
     }
 
-    private function createOutputVariable($team)
+    private function createOutputVariable(array $team): Variable
     {
         $memberNames = array_map(fn ($currentPlayer) => (string) ($currentPlayer->getKey()), $team);
 

src/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php

@@ -9,6 +9,7 @@ use DNW\Skills\Numerics\BasicMath;
 use DNW\Skills\Rating;
 use DNW\Skills\TrueSkill\Factors\GaussianPriorFactor;
 use DNW\Skills\TrueSkill\TrueSkillFactorGraph;
+use DNW\Skills\FactorGraphs\ScheduleSequence;
 
 // We intentionally have no Posterior schedule since the only purpose here is to
 // start the process.
@@ -19,7 +20,7 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
         parent::__construct($parentGraph);
     }
 
-    public function buildLayer()
+    public function buildLayer(): void
     {
         $teams = $this->teams;
         foreach ($teams as $currentTeam) {
@@ -41,7 +42,7 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
         }
     }
 
-    public function createPriorSchedule()
+    public function createPriorSchedule(): ScheduleSequence
     {
         $localFactors = $this->getLocalFactors();
 
@@ -54,7 +55,7 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
         );
     }
 
-    private function createPriorFactor(Rating $priorRating, Variable $skillsVariable)
+    private function createPriorFactor(Rating $priorRating, Variable $skillsVariable): GaussianPriorFactor
     {
         return new GaussianPriorFactor(
             $priorRating->getMean(),

src/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php

@@ -7,7 +7,7 @@ use DNW\Skills\TrueSkill\Factors\GaussianWeightedSumFactor;
 
 class TeamPerformancesToTeamPerformanceDifferencesLayer extends TrueSkillFactorGraphLayer
 {
-    public function buildLayer()
+    public function buildLayer(): void
     {
         $inputVariablesGroups = $this->getInputVariablesGroups();
         $inputVariablesGroupsCount = is_countable($inputVariablesGroups) ? count($inputVariablesGroups) : 0;
@@ -30,14 +30,14 @@ class TeamPerformancesToTeamPerformanceDifferencesLayer extends TrueSkillFactorG
         Variable $strongerTeam,
         Variable $weakerTeam,
         Variable $output
-    ) {
+    ): GaussianWeightedSumFactor {
         $teams = [$strongerTeam, $weakerTeam];
         $weights = [1.0, -1.0];
 
         return new GaussianWeightedSumFactor($output, $teams, $weights);
     }
 
-    private function createOutputVariable()
+    private function createOutputVariable(): Variable
     {
         return $this->getParentFactorGraph()->getVariableFactory()->createBasicVariable('Team performance difference');
     }

src/TrueSkill/TrueSkillFactorGraph.php

@@ -10,6 +10,7 @@ use DNW\Skills\GameInfo;
 use DNW\Skills\Numerics\GaussianDistribution;
 use DNW\Skills\Rating;
 use DNW\Skills\RatingContainer;
+use DNW\Skills\FactorGraphs\FactorGraphLayer;
 use DNW\Skills\TrueSkill\Layers\IteratedTeamDifferencesInnerLayer;
 use DNW\Skills\TrueSkill\Layers\PlayerPerformancesToTeamPerformancesLayer;
 use DNW\Skills\TrueSkill\Layers\PlayerPriorValuesToSkillsLayer;