### Table of Contents * [ComponentRef][1] * [ComponentData][2] * [Properties][3] * [registerComponent][4] * [Parameters][5] * [registerComponents][6] * [Parameters][7] * [hasComponent][8] * [Parameters][9] * [getComponent][10] * [Parameters][11] * [set][12] * [Parameters][13] * [recursivelyInherit][14] * [Parameters][15] * [ComponentSetter][16] * [Properties][17] * [setComponent][18] * [Parameters][19] * [addComponent][20] * [Parameters][21] * [addComponents][22] * [Parameters][23] * [removeComponent][24] * [Parameters][25] * [removeComponents][26] * [Parameters][27] * [addPrefab][28] * [Parameters][29] * [addEntity][30] * [Parameters][31] * [removeEntity][32] * [Parameters][33] * [getEntityComponents][34] * [Parameters][35] * [entityExists][36] * [Parameters][37] * [EntityIndex][38] * [Properties][39] * [aliveCount][40] * [dense][41] * [sparse][42] * [maxId][43] * [versioning][44] * [versionBits][45] * [entityMask][46] * [versionShift][47] * [versionMask][48] * [getId][49] * [Parameters][50] * [getVersion][51] * [Parameters][52] * [incrementVersion][53] * [Parameters][54] * [withVersioning][55] * [Parameters][56] * [createEntityIndex][57] * [Parameters][58] * [addEntityId][59] * [Parameters][60] * [removeEntityId][61] * [Parameters][62] * [isEntityIdAlive][63] * [Parameters][64] * [growDepthsArray][65] * [Parameters][66] * [updateDepthCache][67] * [Parameters][68] * [updateMaxDepth][69] * [Parameters][70] * [setEntityDepth][71] * [Parameters][72] * [invalidateQueryCache][73] * [Parameters][74] * [getHierarchyData][75] * [Parameters][76] * [populateExistingDepths][77] * [Parameters][78] * [ensureDepthTracking][79] * [Parameters][80] * [calculateEntityDepth][81] * [Parameters][82] * [getEntityDepthWithVisited][83] * [Parameters][84] * [getEntityDepth][85] * [Parameters][86] * [markChildrenDirty][87] * [Parameters][88] * [updateHierarchyDepth][89] * [Parameters][90] * [invalidateHierarchyDepth][91] * [Parameters][92] * [invalidateSubtree][93] * [Parameters][94] * [flushDirtyDepths][95] * [Parameters][96] * [queryHierarchy][97] * [Parameters][98] * [queryHierarchyDepth][99] * [Parameters][100] * [getHierarchyDepth][101] * [Parameters][102] * [getMaxHierarchyDepth][103] * [Parameters][104] * [QueryResult][105] * [QueryOptions][106] * [Properties][107] * [Query][108] * [Properties][109] * [QueryOperatorType][110] * [$opType][111] * [$opTerms][112] * [OpReturnType][113] * [Properties][114] * [QueryOperator][115] * [Parameters][116] * [QueryTerm][117] * [HierarchyTerm][118] * [Properties][119] * [Hierarchy][120] * [Parameters][121] * [Cascade][122] * [Parameters][123] * [QueryModifier][124] * [Properties][125] * [ObservableHook][126] * [Parameters][127] * [observe][128] * [Parameters][129] * [queryHash][130] * [Parameters][131] * [registerQuery][132] * [Parameters][133] * [queryInternal][134] * [Parameters][135] * [query][136] * [Parameters][137] * [queryCheckEntity][138] * [Parameters][139] * [queryCheckComponent][140] * [Parameters][141] * [queryAddEntity][142] * [Parameters][143] * [queryCommitRemovals][144] * [Parameters][145] * [commitRemovals][146] * [Parameters][147] * [queryRemoveEntity][148] * [Parameters][149] * [removeQuery][150] * [Parameters][151] * [OnTargetRemovedCallback][152] * [Parameters][153] * [RelationTarget][154] * [$relation][155] * [$pairTarget][156] * [$isPairComponent][157] * [$relationData][158] * [RelationData][159] * [Relation][160] * [Parameters][161] * [createBaseRelation][162] * [withStore][163] * [Parameters][164] * [makeExclusive][165] * [Parameters][166] * [withAutoRemoveSubject][167] * [Parameters][168] * [withOnTargetRemoved][169] * [Parameters][170] * [withValidation][171] * [Parameters][172] * [Pair][173] * [Parameters][174] * [getRelationTargets][175] * [Parameters][176] * [createRelation][177] * [Parameters][178] * [createRelation][179] * [Parameters][180] * [$wildcard][181] * [createWildcardRelation][182] * [getWildcard][183] * [Wildcard][184] * [createIsARelation][185] * [getIsA][186] * [IsA][187] * [isWildcard][188] * [Parameters][189] * [isRelation][190] * [Parameters][191] * [createWorld][192] * [Parameters][193] * [resetWorld][194] * [Parameters][195] * [deleteWorld][196] * [Parameters][197] * [getWorldComponents][198] * [Parameters][199] * [getAllEntities][200] * [Parameters][201] ## ComponentRef Represents a reference to a component. Type: any ## ComponentData Represents the data associated with a component. ### Properties * `id` **[number][202]** The unique identifier for the component. * `generationId` **[number][202]** The generation ID of the component. * `bitflag` **[number][202]** The bitflag used for component masking. * `ref` **[ComponentRef][1]** Reference to the component. * `queries` **[Set][203]<[Query][108]>** Set of queries associated with the component. * `setObservable` **Observable** Observable for component changes. ## registerComponent Registers a component with the world. ### Parameters * `world` **World** The world object. * `component` **[ComponentRef][1]** The component to register. * Throws **[Error][204]** If the component is null or undefined. Returns **[ComponentData][2]** The registered component data. ## registerComponents Registers multiple components with the world. ### Parameters * `world` **World** The world object. * `components` **[Array][205]<[ComponentRef][1]>** Array of components to register. ## hasComponent Checks if an entity has a specific component. ### Parameters * `world` **World** The world object. * `eid` **[number][202]** The entity ID. * `component` **[ComponentRef][1]** The component to check for. Returns **[boolean][206]** True if the entity has the component, false otherwise. ## getComponent Retrieves the data associated with a component for a specific entity. ### Parameters * `world` **World** The world object. * `eid` **EntityId** The entity ID. * `component` **[ComponentRef][1]** The component to retrieve data for. Returns **any** The component data, or undefined if the component is not found or the entity doesn't have the component. ## set Helper function to set component data. ### Parameters * `component` **[ComponentRef][1]** The component to set. * `data` **any** The data to set for the component. Returns **{component: [ComponentRef][1], data: any}** An object containing the component and its data. ## recursivelyInherit Recursvely inherits components from one entity to another. ### Parameters * `ctx` **WorldContext** * `world` **World** The world object. * `baseEid` **[number][202]** The ID of the entity inheriting components. * `inheritedEid` **[number][202]** The ID of the entity being inherited from. * `visited` (optional, default `new Set()`) * `isFirstSuper` **[boolean][206]** Whether this is the first super in the inheritance chain. Returns **void** ## ComponentSetter Represents a component with data to be set on an entity. Type: {component: [ComponentRef][1], data: T} ### Properties * `component` **[ComponentRef][1]** * `data` **T** ## setComponent Sets component data on an entity. Always calls the setter observable even if entity already has the component. ### Parameters * `world` **World** The world object. * `eid` **EntityId** The entity ID. * `component` **[ComponentRef][1]** The component to set. * `data` **any** The data to set for the component. * Throws **[Error][204]** If the entity does not exist in the world. Returns **void** ## addComponent Adds a single component to an entity. ### Parameters * `world` **World** The world object. * `eid` **EntityId** The entity ID. * `componentOrSet` **([ComponentRef][1] | [ComponentSetter][16])** Component to add or set. * Throws **[Error][204]** If the entity does not exist in the world. Returns **[boolean][206]** True if component was added, false if it already existed. ## addComponents Adds multiple components to an entity. ### Parameters * `world` **World** The world object. * `eid` **EntityId** The entity ID. * `components` **([Array][205]<([ComponentRef][1] | [ComponentSetter][16])> | [ComponentRef][1] | [ComponentSetter][16])** Components to add or set (array or spread args). * Throws **[Error][204]** If the entity does not exist in the world. Returns **void** ## removeComponent Removes one or more components from an entity. ### Parameters * `world` **World** The world object. * `eid` **[number][202]** The entity ID. * `components` **...[ComponentRef][1]** Components to remove. * Throws **[Error][204]** If the entity does not exist in the world. ## removeComponents Removes one or more components from an entity. This is an alias for removeComponent. ### Parameters * `world` **World** The world object. * `eid` **EntityId** The entity ID. * `components` **...[ComponentRef][1]** Components to remove. * Throws **[Error][204]** If the entity does not exist in the world. ## addPrefab Creates a new prefab entity in the world. Prefabs are special entities marked with the Prefab component that are excluded from normal queries and can be used as templates for creating other entities. ### Parameters * `world` **World** The world object to create the prefab in. Returns **EntityId** The entity ID of the created prefab. ## addEntity Adds a new entity to the specified world. ### Parameters * `world` **World** Returns **[number][202]** eid ## removeEntity Removes an existing entity from the specified world. ### Parameters * `world` **World** * `eid` **[number][202]** ## getEntityComponents Returns an array of components that an entity possesses. ### Parameters * `world` **any** * `eid` **any** Returns **[Array][205]<[ComponentRef][1]>** ## entityExists Checks the existence of an entity in a world ### Parameters * `world` **World** * `eid` **[number][202]** ## EntityIndex Represents the structure for managing entity IDs. Type: {aliveCount: [number][202], dense: [Array][205]<[number][202]>, sparse: [Array][205]<[number][202]>, maxId: [number][202], versioning: [boolean][206], versionBits: [number][202], entityMask: [number][202], versionShift: [number][202], versionMask: [number][202]} ### Properties * `aliveCount` **[number][202]** * `dense` **[Array][205]<[number][202]>** * `sparse` **[Array][205]<[number][202]>** * `maxId` **[number][202]** * `versioning` **[boolean][206]** * `versionBits` **[number][202]** * `entityMask` **[number][202]** * `versionShift` **[number][202]** * `versionMask` **[number][202]** ### aliveCount The number of currently alive entities. Type: [number][202] ### dense Array of entity IDs, densely packed. Type: [Array][205]<[number][202]> ### sparse Sparse array mapping entity IDs to their index in the dense array. Type: [Array][205]<[number][202]> ### maxId The highest entity ID that has been assigned. Type: [number][202] ### versioning Flag indicating if versioning is enabled. Type: [boolean][206] ### versionBits Number of bits used for versioning. Type: [number][202] ### entityMask Bit mask for entity ID. Type: [number][202] ### versionShift Bit shift for version. Type: [number][202] ### versionMask Bit mask for version. Type: [number][202] ## getId Extracts the entity ID from a versioned entity ID by stripping off the version. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex containing the masks. * `id` **[number][202]** The versioned entity ID. Returns **[number][202]** The entity ID without the version. ## getVersion Extracts the version from an entity ID. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex containing the masks and shifts. * `id` **[number][202]** The entity ID. Returns **[number][202]** The version. ## incrementVersion Increments the version of an entity ID. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex containing the masks and shifts. * `id` **[number][202]** The entity ID. Returns **[number][202]** The new entity ID with incremented version. ## withVersioning Creates configuration options for entity ID recycling with versioning. ### Parameters * `versionBits` **[number][202]?** Optional number of bits to use for version numbers. Defaults to 8 if not specified. Returns **[object][207]** Configuration object with versioning enabled and specified version bits. ## createEntityIndex Creates and initializes a new EntityIndex. ### Parameters * `options` **([object][207] | [function][208])?** Optional configuration object from withVersioning() or withVersioning function. * `options.versioning` **[boolean][206]** Flag to enable versioning for recycled IDs. * `options.versionBits` **[number][202]** Number of bits to use for versioning (default: 8). Returns **[EntityIndex][38]** A new EntityIndex object. ## addEntityId Adds a new entity ID to the index or recycles an existing one. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex to add to. Returns **[number][202]** The new or recycled entity ID. ## removeEntityId Removes an entity ID from the index. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex to remove from. * `id` **[number][202]** The entity ID to remove. Returns **void** ## isEntityIdAlive Checks if an entity ID is currently alive in the index. ### Parameters * `index` **[EntityIndex][38]** The EntityIndex to check. * `id` **[number][202]** The entity ID to check. Returns **[boolean][206]** True if the entity ID is alive, false otherwise. ## growDepthsArray Grows the depths array to accommodate a specific entity ### Parameters * `hierarchyData` **HierarchyData** * `entity` **EntityId** Returns **[Uint32Array][209]** ## updateDepthCache Updates the depthToEntities cache when an entity's depth changes ### Parameters * `hierarchyData` **HierarchyData** * `entity` **EntityId** * `newDepth` **[number][202]** * `oldDepth` **[number][202]?** Returns **void** ## updateMaxDepth Updates max depth if the new depth is greater ### Parameters * `hierarchyData` **HierarchyData** * `depth` **[number][202]** Returns **void** ## setEntityDepth Sets entity depth and updates all related caches ### Parameters * `hierarchyData` **HierarchyData** * `entity` **EntityId** * `newDepth` **[number][202]** * `oldDepth` **[number][202]?** Returns **void** ## invalidateQueryCache Invalidates hierarchy query cache for a relation ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** Returns **void** ## getHierarchyData Gets hierarchy data for a relation, activating tracking if needed ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** Returns **HierarchyData** ## populateExistingDepths Populates depth calculations for all existing entities with this relation ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** Returns **void** ## ensureDepthTracking Ensures depth tracking is initialized for a relation. This must be called before using hierarchy features for a specific relation component. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component to initialize tracking for. Returns **void** ## calculateEntityDepth Calculates the hierarchy depth of an entity for a given relation. Depth is measured as the distance from the root entities (entities with no parent relations). ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component to calculate depth for. * `entity` **EntityId** The entity ID to calculate depth for. * `visited` **[Set][203]\?** Internal set to track visited entities for cycle detection. (optional, default `new Set()`) Returns **[number][202]** The hierarchy depth of the entity. ## getEntityDepthWithVisited Internal helper to get entity depth with cycle detection ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** * `entity` **EntityId** * `visited` **[Set][203]\** Returns **[number][202]** ## getEntityDepth Gets the cached depth of an entity, calculating if needed ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** * `entity` **EntityId** Returns **[number][202]** ## markChildrenDirty Marks an entity and its children as needing depth recalculation. This is used internally when hierarchy changes occur. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component. * `parent` **EntityId** The parent entity ID. * `dirty` **SparseSet** The set to mark dirty entities in. * `visited` **SparseSet?** Internal set to track visited entities for cycle detection. (optional, default `createSparseSet()`) Returns **void** ## updateHierarchyDepth Updates hierarchy depth when a relation is added. This function is called automatically when components are added to maintain accurate depth tracking. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component. * `entity` **EntityId** The entity ID that had a relation added. * `parent` **EntityId?** The parent entity ID in the relation. * `updating` **[Set][203]\?** Internal set to track entities being updated. (optional, default `new Set()`) Returns **void** ## invalidateHierarchyDepth Invalidates hierarchy depth when a relation is removed. This function is called automatically when components are removed to maintain accurate depth tracking. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component. * `entity` **EntityId** The entity ID that had a relation removed. Returns **void** ## invalidateSubtree Recursively invalidates an entire subtree ### Parameters * `world` **World** * `relation` **[ComponentRef][1]** * `entity` **EntityId** * `depths` **[Uint32Array][209]** * `visited` **SparseSet** Returns **void** ## flushDirtyDepths Processes all dirty depth calculations for a relation. This ensures all cached depth values are up to date before performing hierarchy operations. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component to flush dirty depths for. Returns **void** ## queryHierarchy Query entities in hierarchical order (depth-based ordering). Returns entities grouped by depth: all depth 0, then depth 1, then depth 2, etc. This ensures parents always come before their children. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component that defines the hierarchy. * `components` **[Array][205]<[ComponentRef][1]>** Additional components to filter by. * `options` **[Object][207]?** Query options. (optional, default `{}`) * `options.buffered` **[boolean][206]?** Whether to return results as Uint32Array instead of number\[]. Returns **[QueryResult][105]** Array or Uint32Array of entity IDs in hierarchical order. ## queryHierarchyDepth Get all entities at a specific depth level in the hierarchy. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component that defines the hierarchy. * `depth` **[number][202]** The specific depth level to query (0 = root level). * `options` **[Object][207]?** Query options. (optional, default `{}`) * `options.buffered` **[boolean][206]?** Whether to return results as Uint32Array instead of number\[]. Returns **[QueryResult][105]** Array or Uint32Array of entity IDs at the specified depth. ## getHierarchyDepth Get the hierarchy depth of a specific entity for a given relation. ### Parameters * `world` **World** The world object. * `entity` **EntityId** The entity ID to get depth for. * `relation` **[ComponentRef][1]** The relation component that defines the hierarchy. Returns **[number][202]** The depth of the entity (0 = root level, higher numbers = deeper). ## getMaxHierarchyDepth Get the maximum depth in the hierarchy for a given relation. ### Parameters * `world` **World** The world object. * `relation` **[ComponentRef][1]** The relation component that defines the hierarchy. Returns **[number][202]** The maximum depth found in the hierarchy. ## QueryResult The result of a query, either as a Uint32Array or a readonly array of numbers. Type: ([Uint32Array][209] | any) ## QueryOptions Options for configuring query behavior. Type: [Object][207] ### Properties * `commit` **[boolean][206]?** Whether to commit pending entity removals before querying. * `buffered` **[boolean][206]?** Whether to return results as Uint32Array instead of number\[]. ## Query Represents a query in the ECS using original blazing-fast bitmask evaluation. Type: [Object][207] ### Properties * `allComponents` **[Array][205]<[ComponentRef][1]>** All components referenced in the query. * `orComponents` **[Array][205]<[ComponentRef][1]>** Components in an OR relationship. * `notComponents` **[Array][205]<[ComponentRef][1]>** Components that should not be present. * `masks` **Record<[number][202], [number][202]>** Bitmasks for each component generation. * `orMasks` **Record<[number][202], [number][202]>** OR bitmasks for each component generation. * `notMasks` **Record<[number][202], [number][202]>** NOT bitmasks for each component generation. * `hasMasks` **Record<[number][202], [number][202]>** HAS bitmasks for each component generation. * `generations` **[Array][205]<[number][202]>** Component generations. * `toRemove` **SparseSet** Set of entities to be removed. ## QueryOperatorType Types of query operators. Type: (`"Or"` | `"And"` | `"Not"`) ## $opType Symbol for query operator type. Type: [Symbol][210] ## $opTerms Symbol for query operator terms. Type: [Symbol][210] ## OpReturnType Type: [Object][207] ### Properties * `$opType` **[symbol][210]?** The type of the operator. * `$opTerms` **[symbol][210]?** The components involved in the operation. ## QueryOperator A function that creates a query operator. Type: [Function][208] ### Parameters * `components` **...[ComponentRef][1]** The components to apply the operator to. Returns **[OpReturnType][113]** The result of the operator. ## QueryTerm A term in a query, either a component reference, query operator, or hierarchy term. Type: ([ComponentRef][1] | [QueryOperator][115] | [HierarchyTerm][118]) ## HierarchyTerm Represents a hierarchy query term for topological ordering. Type: [Object][207] ### Properties * `$hierarchyType` **[symbol][210]?** Always 'Hierarchy'. * `$hierarchyRel` **[ComponentRef][1]?** The relation component for hierarchy. * `$hierarchyDepth` **[number][202]?** Optional depth limit. ## Hierarchy Creates a hierarchy query term for topological ordering (parents before children). ### Parameters * `relation` **[ComponentRef][1]** The relation component (e.g., ChildOf). * `depth` **[number][202]?** Optional depth limit. Returns **[HierarchyTerm][118]** The hierarchy term. ## Cascade Alias for Hierarchy - creates a hierarchy query term for topological ordering. ### Parameters * `relation` **[ComponentRef][1]** The relation component (e.g., ChildOf). * `depth` **[number][202]?** Optional depth limit. Returns **[HierarchyTerm][118]** The hierarchy term. ## QueryModifier Represents a query modifier that can be mixed into query terms. Type: [Object][207] ### Properties * `$modifierType` **[symbol][210]?** The type of modifier ('buffer' | 'nested'). ## ObservableHook A function that creates an observable hook for queries. Type: [Function][208] ### Parameters * `terms` **...[QueryTerm][117]** The query terms to observe. ## observe Observes changes in entities based on specified components. ### Parameters * `world` **World** The world object. * `hook` **[ObservableHook][126]** The observable hook. * `callback` **function ([number][202]): any** The callback function to execute when changes occur. Returns **function (): void** A function to unsubscribe from the observation. ## queryHash Generates a hash for a query based on its terms. ### Parameters * `world` **World** The world object. * `terms` **[Array][205]<[QueryTerm][117]>** The query terms. Returns **[string][211]** The generated hash. ## registerQuery Registers a new query in the world using unified clause-mask compilation. ### Parameters * `world` **World** The world object. * `terms` **[Array][205]<[QueryTerm][117]>** The query terms. * `options` **[Object][207]?** Additional options. * `options.buffered` **[boolean][206]?** Whether the query should be buffered. Returns **[Query][108]** The registered query. ## queryInternal Internal implementation for nested queries. ### Parameters * `world` **World** The world object. * `terms` **[Array][205]<[QueryTerm][117]>** The query terms. * `options` **[Object][207]?** Additional options. * `options.buffered` **[boolean][206]?** Whether the query should be buffered. Returns **[QueryResult][105]** The result of the query. ## query Performs a unified query operation with configurable options. ### Parameters * `world` **World** The world object. * `terms` **[Array][205]<[QueryTerm][117]>** The query terms. * `modifiers` **...[QueryModifier][124]** Query modifiers (asBuffer, isNested, etc.). Returns **[QueryResult][105]** The result of the query. ## queryCheckEntity Original blazing-fast query evaluation using simple bitmasks. ### Parameters * `world` **World** The world object. * `query` **[Query][108]** The query to check against. * `eid` **[number][202]** The entity ID to check. Returns **[boolean][206]** True if the entity matches the query, false otherwise. ## queryCheckComponent Checks if a component matches a query. ### Parameters * `query` **[Query][108]** The query to check against. * `c` **[ComponentData][2]** The component data to check. Returns **[boolean][206]** True if the component matches the query, false otherwise. ## queryAddEntity Adds an entity to a query. ### Parameters * `query` **[Query][108]** The query to add the entity to. * `eid` **[number][202]** The entity ID to add. ## queryCommitRemovals Commits removals for a query. ### Parameters * `query` **[Query][108]** The query to commit removals for. ## commitRemovals Commits all pending removals for queries in the world. ### Parameters * `world` **World** The world object. ## queryRemoveEntity Removes an entity from a query. ### Parameters * `world` **World** The world object. * `query` **[Query][108]** The query to remove the entity from. * `eid` **[number][202]** The entity ID to remove. ## removeQuery Removes a query from the world. ### Parameters * `world` **World** The world object. * `terms` **[Array][205]<[QueryTerm][117]>** The query terms of the query to remove. ## OnTargetRemovedCallback Callback function type for when a target is removed from a relation. Type: [Function][208] ### Parameters * `subject` **[number][202]** The subject entity ID. * `target` **[number][202]** The target entity ID. ## RelationTarget Possible types for a relation target. Type: ([number][202] | `"*"` | any) ## $relation Symbol for accessing the relation of a component. Type: [Symbol][210] ## $pairTarget Symbol for accessing the pair target of a component. Type: [Symbol][210] ## $isPairComponent Symbol for checking if a component is a pair component. Type: [Symbol][210] ## $relationData Symbol for accessing the relation data of a component. Type: [Symbol][210] ## RelationData Interface for relation data. ## Relation Type definition for a Relation function. Type: [function][208] ### Parameters * `target` **[RelationTarget][154]** The target of the relation. Returns **T** The relation component. ## createBaseRelation Creates a base relation. Returns **[Relation][155]\** The created base relation. ## withStore Adds a store to a relation. ### Parameters * `createStore` **function (): T** Function to create the store. Returns **function ([Relation][155]\): [Relation][155]\** A function that modifies the relation. ## makeExclusive Makes a relation exclusive. ### Parameters * `relation` **[Relation][155]\** The relation to make exclusive. Returns **[Relation][155]\** The modified relation. ## withAutoRemoveSubject Adds auto-remove subject behavior to a relation. ### Parameters * `relation` **[Relation][155]\** The relation to modify. Returns **[Relation][155]\** The modified relation. ## withOnTargetRemoved Adds an onTargetRemoved callback to a relation. ### Parameters * `onRemove` **[OnTargetRemovedCallback][152]** The callback to add. Returns **function ([Relation][155]\): [Relation][155]\** A function that modifies the relation. ## withValidation Adds validation to a relation. ### Parameters * `validateFn` **function (T): [boolean][206]** The validation function. Returns **function ([Relation][155]\): [Relation][155]\** A function that modifies the relation. ## Pair Creates a pair from a relation and a target. ### Parameters * `relation` **[Relation][155]\** The relation. * `target` **[RelationTarget][154]** The target. * Throws **[Error][204]** If the relation is undefined. Returns **T** The created pair. ## getRelationTargets Gets the relation targets for an entity. ### Parameters * `world` **World** The world object. * `eid` **[number][202]** The entity ID. * `relation` **[Relation][155]\** The relation to get targets for. Returns **[Array][205]\** An array of relation targets. ## createRelation Creates a new relation. ### Parameters * `modifiers` **...[Array][205]\): [Relation][155]\>** Modifier functions for the relation. Returns **[Relation][155]\** The created relation. ## createRelation Creates a new relation with options. ### Parameters * `options` **[Object][207]** Options for creating the relation. * `options.store` **function (): T?** Function to create the store. * `options.exclusive` **[boolean][206]?** Whether the relation is exclusive. * `options.autoRemoveSubject` **[boolean][206]?** Whether to auto-remove the subject. * `options.onTargetRemoved` **[OnTargetRemovedCallback][152]?** Callback for when a target is removed. Returns **[Relation][155]\** The created relation. ## $wildcard Symbol used to mark a relation as a wildcard relation ## createWildcardRelation Creates a wildcard relation that matches any target. Returns **[Relation][155]\** The created wildcard relation. ## getWildcard Gets the singleton wildcard instance. Returns **[Relation][155]\** The global wildcard relation instance. ## Wildcard Wildcard relation. Type: [Relation][155]\ ## createIsARelation Creates an IsA relation. Returns **[Relation][155]\** The created IsA relation. ## getIsA Gets the singleton IsA instance. Returns **[Relation][155]\** The global IsA relation instance. ## IsA IsA relation. Type: [Relation][155]\ ## isWildcard Checks if a relation is a wildcard relation. ### Parameters * `relation` **any** The relation to check. Returns **[boolean][206]** True if the relation is a wildcard relation, false otherwise. ## isRelation Checks if a component is a relation. ### Parameters * `component` **any** The component to check. Returns **[boolean][206]** True if the component is a relation, false otherwise. ## createWorld Creates a new world with various configurations. ### Parameters * `args` **...[Array][205]<([EntityIndex][38] | [object][207])>** EntityIndex, context object, or both. Returns **World\** The created world. ## resetWorld Resets a world. ### Parameters * `world` **World** Returns **[object][207]** ## deleteWorld Deletes a world by removing its internal data. ### Parameters * `world` **World** The world to be deleted. ## getWorldComponents Returns all components registered to a world ### Parameters * `world` **World** Returns **any** Array ## getAllEntities Returns all existing entities in a world ### Parameters * `world` **World** Returns **any** Array [1]: #componentref [2]: #componentdata [3]: #properties [4]: #registercomponent [5]: #parameters [6]: #registercomponents [7]: #parameters-1 [8]: #hascomponent [9]: #parameters-2 [10]: #getcomponent [11]: #parameters-3 [12]: #set [13]: #parameters-4 [14]: #recursivelyinherit [15]: #parameters-5 [16]: #componentsetter [17]: #properties-1 [18]: #setcomponent [19]: #parameters-6 [20]: #addcomponent [21]: #parameters-7 [22]: #addcomponents [23]: #parameters-8 [24]: #removecomponent [25]: #parameters-9 [26]: #removecomponents [27]: #parameters-10 [28]: #addprefab [29]: #parameters-11 [30]: #addentity [31]: #parameters-12 [32]: #removeentity [33]: #parameters-13 [34]: #getentitycomponents [35]: #parameters-14 [36]: #entityexists [37]: #parameters-15 [38]: #entityindex [39]: #properties-2 [40]: #alivecount [41]: #dense [42]: #sparse [43]: #maxid [44]: #versioning [45]: #versionbits [46]: #entitymask [47]: #versionshift [48]: #versionmask [49]: #getid [50]: #parameters-16 [51]: #getversion [52]: #parameters-17 [53]: #incrementversion [54]: #parameters-18 [55]: #withversioning [56]: #parameters-19 [57]: #createentityindex [58]: #parameters-20 [59]: #addentityid [60]: #parameters-21 [61]: #removeentityid [62]: #parameters-22 [63]: #isentityidalive [64]: #parameters-23 [65]: #growdepthsarray [66]: #parameters-24 [67]: #updatedepthcache [68]: #parameters-25 [69]: #updatemaxdepth [70]: #parameters-26 [71]: #setentitydepth [72]: #parameters-27 [73]: #invalidatequerycache [74]: #parameters-28 [75]: #gethierarchydata [76]: #parameters-29 [77]: #populateexistingdepths [78]: #parameters-30 [79]: #ensuredepthtracking [80]: #parameters-31 [81]: #calculateentitydepth [82]: #parameters-32 [83]: #getentitydepthwithvisited [84]: #parameters-33 [85]: #getentitydepth [86]: #parameters-34 [87]: #markchildrendirty [88]: #parameters-35 [89]: #updatehierarchydepth [90]: #parameters-36 [91]: #invalidatehierarchydepth [92]: #parameters-37 [93]: #invalidatesubtree [94]: #parameters-38 [95]: #flushdirtydepths [96]: #parameters-39 [97]: #queryhierarchy [98]: #parameters-40 [99]: #queryhierarchydepth [100]: #parameters-41 [101]: #gethierarchydepth [102]: #parameters-42 [103]: #getmaxhierarchydepth [104]: #parameters-43 [105]: #queryresult [106]: #queryoptions [107]: #properties-3 [108]: #query [109]: #properties-4 [110]: #queryoperatortype [111]: #optype [112]: #opterms [113]: #opreturntype [114]: #properties-5 [115]: #queryoperator [116]: #parameters-44 [117]: #queryterm [118]: #hierarchyterm [119]: #properties-6 [120]: #hierarchy [121]: #parameters-45 [122]: #cascade [123]: #parameters-46 [124]: #querymodifier [125]: #properties-7 [126]: #observablehook [127]: #parameters-47 [128]: #observe [129]: #parameters-48 [130]: #queryhash [131]: #parameters-49 [132]: #registerquery [133]: #parameters-50 [134]: #queryinternal [135]: #parameters-51 [136]: #query-1 [137]: #parameters-52 [138]: #querycheckentity [139]: #parameters-53 [140]: #querycheckcomponent [141]: #parameters-54 [142]: #queryaddentity [143]: #parameters-55 [144]: #querycommitremovals [145]: #parameters-56 [146]: #commitremovals [147]: #parameters-57 [148]: #queryremoveentity [149]: #parameters-58 [150]: #removequery [151]: #parameters-59 [152]: #ontargetremovedcallback [153]: #parameters-60 [154]: #relationtarget [155]: #relation [156]: #pairtarget [157]: #ispaircomponent [158]: #relationdata [159]: #relationdata-1 [160]: #relation-1 [161]: #parameters-61 [162]: #createbaserelation [163]: #withstore [164]: #parameters-62 [165]: #makeexclusive [166]: #parameters-63 [167]: #withautoremovesubject [168]: #parameters-64 [169]: #withontargetremoved [170]: #parameters-65 [171]: #withvalidation [172]: #parameters-66 [173]: #pair [174]: #parameters-67 [175]: #getrelationtargets [176]: #parameters-68 [177]: #createrelation [178]: #parameters-69 [179]: #createrelation-1 [180]: #parameters-70 [181]: #wildcard [182]: #createwildcardrelation [183]: #getwildcard [184]: #wildcard-1 [185]: #createisarelation [186]: #getisa [187]: #isa [188]: #iswildcard [189]: #parameters-71 [190]: #isrelation [191]: #parameters-72 [192]: #createworld [193]: #parameters-73 [194]: #resetworld [195]: #parameters-74 [196]: #deleteworld [197]: #parameters-75 [198]: #getworldcomponents [199]: #parameters-76 [200]: #getallentities [201]: #parameters-77 [202]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number [203]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Set [204]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error [205]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array [206]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean [207]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object [208]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function [209]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Uint32Array [210]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Symbol [211]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String