Package com.google.javascript.rhino.jstype

Class ObjectType

java.lang.Object
com.google.javascript.rhino.jstype.JSType
com.google.javascript.rhino.jstype.ObjectType
Direct Known Subclasses:
EnumElementType, PrototypeObjectType, ProxyObjectType, UnknownType
public abstract class ObjectType extends JSType
Object type.

In JavaScript, all object types have properties, and each of those properties has a type. Property types may be DECLARED, INFERRED, or UNKNOWN.

DECLARED properties have an explicit type annotation, as in: /xx @type {number} x/ Foo.prototype.bar = 1; This property may only hold number values, and an assignment to any other type of value is an error.

INFERRED properties do not have an explicit type annotation. Rather, we try to find all the possible types that this property can hold. Foo.prototype.bar = 1; If the programmer assigns other types of values to this property, the property will take on the union of all these types.

UNKNOWN properties are properties on the UNKNOWN type. The UNKNOWN type has all properties, but we do not know whether they are declared or inferred.

  • Method Details

    • getSlot

      public @Nullable Property getSlot(String name)
      Default getSlot implementation. This gets overridden by FunctionType for lazily-resolved prototypes.

    • getOwnSlot

      public final Property getOwnSlot(String name)

    • getTypeOfThis

      public JSType getTypeOfThis()

    • getTemplateTypes

      public com.google.common.collect.ImmutableList<JSType> getTemplateTypes()
      Gets the declared default element type.
      See Also:

    • getJSDocInfo

      public JSDocInfo getJSDocInfo()
      Gets the docInfo for this type.
      Overrides:
      getJSDocInfo in class JSType

    • setJSDocInfo

      public void setJSDocInfo(JSDocInfo info)
      Sets the docInfo for this type from the given JSDocInfo. The JSDocInfo may be null.

    • getReferenceName

      public abstract @Nullable String getReferenceName()
      Gets the reference name for this object. This includes named types like constructors, prototypes, and enums. It notably does not include literal types like strings and booleans and structural types.

      Returning an empty string means something different than returning null. An empty string may indicate an anonymous constructor, which we treat differently than a literal type without a reference name. e.g. in InstanceObjectType.appendTo(TypeStringBuilder)

      Returns:
      the object's name or null if this is an anonymous object

    • hasReferenceName

      public final boolean hasReferenceName()
      INVARIANT: hasReferenceName() is true if and only if getReferenceName() returns a non-null string.
      Returns:
      true if the object is named, false if it is anonymous

    • getNormalizedReferenceName

      public final @Nullable String getNormalizedReferenceName()
      Due to the complexity of some of our internal type systems, sometimes we have different types constructed by the same constructor. In other parts of the type system, these are called delegates. We construct these types by appending suffixes to the constructor name.

      The normalized reference name does not have these suffixes, and as such, recollapses these implicit types back to their real type. Note that suffixes such as ".prototype" can be added after the delegate suffix, so anything after the parentheses must still be retained.

    • getDisplayName

      public String getDisplayName()
      Description copied from class: JSType
      Returns a user meaningful label for the JSType instance. For example, Functions and Enums will return their declaration name (if they have one). Some types will not have a meaningful display name. Calls to hasDisplayName() will return true IFF getDisplayName() will return null or a zero length string.
      Overrides:
      getDisplayName in class JSType
      Returns:
      the display name of the type, or null if one is not available

    • createDelegateSuffix

      public static String createDelegateSuffix(String suffix)
      Creates a suffix for a proxy delegate.
      See Also:

    • getRawType

      public final ObjectType getRawType()

    • testForEquality

      public Tri testForEquality(JSType that)
      Description copied from class: JSType
      Compares this and that.
      Overrides:
      testForEquality in class JSType
      Returns:
      • Tri.TRUE if the comparison of values of this type and that always succeed (such as undefined compared to null)
      • Tri.FALSE if the comparison of values of this type and that always fails (such as undefined compared to number)
      • Tri.UNKNOWN if the comparison can succeed or fail depending on the concrete values

    • getConstructor

      public abstract FunctionType getConstructor()
      Gets this object's constructor.
      Returns:
      this object's constructor or null if it is a native object (constructed natively v.s. by instantiation of a function)

    • getSuperClassConstructor

      public @Nullable FunctionType getSuperClassConstructor()

    • getClosestDefiningType

      public final @Nullable ObjectType getClosestDefiningType(String propertyName)
      Returns the closest ancestor that defines the property including this type itself.

    • findClosestDefinition

      public final Property.OwnedProperty findClosestDefinition(String propertyName)
      Returns the closest definition of the property including this type itself.

    • getImplicitPrototype

      public abstract ObjectType getImplicitPrototype()
      Gets the implicit prototype (a.k.a. the [[Prototype]] property).

    • getImplicitPrototypeChain

      public final Iterable<ObjectType> getImplicitPrototypeChain()
      Returns a lazy, dynamic Iterable for the types forming the implicit prototype chain of this type.

      The chain is iterated bottom to top; from the nearest ancestor to the most distant. Iteration stops when the next ancestor would be a null reference.

      The created Iterators will not reflect changes to the prototype chain of elements it has already iterated past, but will reflect those of upcoming elements. Neither the Iterable nor its Iterator support mutation.

    • defineDeclaredProperty

      public final boolean defineDeclaredProperty(String propertyName, JSType type, Node propertyNode)
      Defines a property whose type is explicitly declared by the programmer.
      Parameters:
      propertyName - the property's name
      type - the type
      propertyNode - the node corresponding to the declaration of property which might later be accessed using getPropertyNode.

    • defineSynthesizedProperty

      public final boolean defineSynthesizedProperty(String propertyName, JSType type, Node propertyNode)
      Defines a property whose type is on a synthesized object. These objects don't actually exist in the user's program. They're just used for bookkeeping in the type system.

    • defineInferredProperty

      public final boolean defineInferredProperty(String propertyName, JSType type, Node propertyNode)
      Defines a property whose type is inferred.
      Parameters:
      propertyName - the property's name
      type - the type
      propertyNode - the node corresponding to the inferred definition of property that might later be accessed using getPropertyNode.

    • getPropertyNode

      public final @Nullable Node getPropertyNode(String propertyName)
      Gets the node corresponding to the definition of the specified property. This could be the node corresponding to declaration of the property or the node corresponding to the first reference to this property, e.g., "this.propertyName" in a constructor. Note this is mainly intended to be an estimate of where in the source code a property is defined. Sometime the returned node is not even part of the global AST but in the AST of the JsDoc that defines a type.
      Parameters:
      propertyName - the name of the property
      Returns:
      the Node corresponding to the property or null.

    • getPropertyDefSite

      public final Node getPropertyDefSite(String propertyName)

    • getPropertyJSDocInfo

      public final @Nullable JSDocInfo getPropertyJSDocInfo(String propertyName)

    • getOwnPropertyJSDocInfo

      public final @Nullable JSDocInfo getOwnPropertyJSDocInfo(String propertyName)
      Gets the docInfo on the specified property on this type. This should not be implemented recursively, as you generally need to know exactly on which type in the prototype chain the JSDocInfo exists.

    • getOwnPropertyDefSite

      public final @Nullable Node getOwnPropertyDefSite(String propertyName)

    • setPropertyJSDocInfo

      public void setPropertyJSDocInfo(String propertyName, JSDocInfo info)
      Sets the docInfo for the specified property from the JSDocInfo on its definition.
      Parameters:
      info - JSDocInfo for the property definition. May be null.

    • setPropertyNode

      public void setPropertyNode(String propertyName, Node defSite)
      Sets the node where the property was defined.

    • findPropertyTypeWithoutConsideringTemplateTypes

      protected @Nullable JSType findPropertyTypeWithoutConsideringTemplateTypes(String propertyName)
      Description copied from class: JSType
      Looks up a property on this type, but without properly replacing any templates in the result.

      Subclasses can override this if they need more complicated logic for property lookup than just autoboxing to an object.

      This is only for use by findPropertyType(JSType). Call that method instead if you need to lookup a property on a random JSType

      Overrides:
      findPropertyTypeWithoutConsideringTemplateTypes in class JSType

    • getPropertyType

      public JSType getPropertyType(String propertyName)
      Gets the property type of the property whose name is given. If the underlying object does not have this property, the Unknown type is returned to indicate that no information is available on this property. This gets overridden by FunctionType for lazily-resolved call() and bind() functions.
      Returns:
      the property's type or UnknownType. This method never returns null.

    • getPropertyKind

      public JSType.HasPropertyKind getPropertyKind(String propertyName, boolean autobox)
      Description copied from class: JSType
      Checks whether the property is present on the object.
      Overrides:
      getPropertyKind in class JSType
      Parameters:
      propertyName - The property name.
      autobox - Whether to check for the presents on an autoboxed type

    • getOwnPropertyKind

      public final JSType.HasPropertyKind getOwnPropertyKind(String propertyName)
      Checks whether the property whose name is given is present directly on the object. Returns false even if it is declared on a supertype.

    • hasOwnProperty

      public final boolean hasOwnProperty(String propertyName)
      Checks whether the property whose name is given is present directly on the object. Returns false even if it is declared on a supertype.

    • getOwnPropertyNames

      public Set<String> getOwnPropertyNames()
      Returns the names of all the properties directly on this type. Overridden by FunctionType to add "prototype".

    • isPropertyTypeInferred

      public final boolean isPropertyTypeInferred(String propertyName)
      Checks whether the property's type is inferred.

    • isPropertyTypeDeclared

      public final boolean isPropertyTypeDeclared(String propertyName)
      Checks whether the property's type is declared.

    • isStructuralType

      public boolean isStructuralType()
      Overrides:
      isStructuralType in class JSType

    • hasOwnDeclaredProperty

      public final boolean hasOwnDeclaredProperty(String name)
      Whether the given property is declared on this object.

    • isPropertyInExterns

      public final boolean isPropertyInExterns(String propertyName)
      Checks whether the property was defined in the externs.

    • getPropertiesCount

      public final int getPropertiesCount()
      Gets the number of properties of this object.

    • getPropertyNames

      public final com.google.common.collect.ImmutableSortedSet<String> getPropertyNames()
      Returns a list of properties defined or inferred on this type and any of its supertypes.

    • visit

      public <T> T visit(Visitor<T> visitor)
      Description copied from class: JSType
      Visit this type with the given visitor.
      Specified by:
      visit in class JSType
      Returns:
      the value returned by the visitor
      See Also:

    • getPossibleToBooleanOutcomes

      public BooleanLiteralSet getPossibleToBooleanOutcomes()
      Description copied from class: JSType
      Computes the set of possible outcomes of the ToBoolean predicate for this type. The ToBoolean predicate is defined by the ECMA-262 standard, 3rd edition. Its behavior for simple types can be summarized by the following table:
      ToBoolean results by input type
      typeresult
      undefined{false}
      null{false}
      boolean{true, false}
      number{true, false}
      string{true, false}
      Object{true}
      Specified by:
      getPossibleToBooleanOutcomes in class JSType
      Returns:
      the set of boolean literals for this type

    • isUnknownType

      public boolean isUnknownType()
      We treat this as the unknown type if any of its implicit prototype properties is unknown.
      Overrides:
      isUnknownType in class JSType

    • isObject

      public boolean isObject()
      Description copied from class: JSType
      Tests whether this type is an Object, or any subtype thereof.
      Overrides:
      isObject in class JSType
      Returns:
      this <: Object

    • hasCachedValues

      public boolean hasCachedValues()
      Returns true if any cached values have been set for this type. If true, then the prototype chain should not be changed, as it might invalidate the cached values.

    • clearCachedValues

      public void clearCachedValues()
      Clear cached values. Should be called before making changes to a prototype that may have been changed since creation.

    • isNativeObjectType

      public boolean isNativeObjectType()
      Whether this is a built-in object.
      Overrides:
      isNativeObjectType in class JSType

    • cast

      public static @Nullable ObjectType cast(JSType type)
      A null-safe version of JSType#toObjectType.

    • isFunctionPrototypeType

      public final boolean isFunctionPrototypeType()
      Description copied from class: JSType
      Whether this is the prototype of a function.
      Overrides:
      isFunctionPrototypeType in class JSType

    • getOwnerFunction

      public FunctionType getOwnerFunction()

    • getCtorImplementedInterfaces

      public Iterable<ObjectType> getCtorImplementedInterfaces()
      Gets the interfaces implemented by the ctor associated with this type. Intended to be overridden by subclasses.

    • getCtorExtendedInterfaces

      public Iterable<ObjectType> getCtorExtendedInterfaces()
      Gets the interfaces extended by the interface associated with this type. Intended to be overridden by subclasses.

    • getPropertyTypeMap

      public Map<String,JSType> getPropertyTypeMap()
      get the map of properties to types covered in an object type
      Returns:
      a Map that maps the property's name to the property's type

    • getEnumeratedTypeOfEnumObject

      public JSType getEnumeratedTypeOfEnumObject()