Package com.google.javascript.rhino.jstype

Class NoObjectType

  • All Implemented Interfaces:
    java.io.Serializable
    Direct Known Subclasses:
    NoType
    public class NoObjectType
extends FunctionType
    The bottom Object type, representing the subclass of all objects.

    Although JavaScript programmers can't explicitly denote the bottom Object type, it comes up in static analysis. For example, if we have: var x = function() {}; if (x instanceof Array) { f(x); } We need to be able to assign x a type within the f(x) call. It has no possible type, but x would not be legal if f expected a string. So we assign it the NoObjectType.

    See Also:
    Bottom types, Serialized Form

    • Method Detail

      • toMaybeFunctionType

        public final FunctionType toMaybeFunctionType()
        Description copied from class: JSType
        Downcasts this to a FunctionType, or returns null if this is not a function.

        For the purposes of this function, we define a MaybeFunctionType as any type in the sub-lattice { x | LEAST_FUNCTION_TYPE <= x <= GREATEST_FUNCTION_TYPE } This definition excludes bottom types like NoType and NoObjectType.

        This definition is somewhat arbitrary and axiomatic, but this is the definition that makes the most sense for the most callers.

        Overrides:
        toMaybeFunctionType in class FunctionType

      • getReferenceName

        public java.lang.String getReferenceName()
        Description copied from class: ObjectType
        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)

        Overrides:
        getReferenceName in class PrototypeObjectType
        Returns:
        the object's name or null if this is an anonymous object

      • matchesNumberContext

        public final boolean matchesNumberContext()
        Description copied from class: JSType
        This predicate is used to test whether a given type can appear in a numeric context, such as an operand of a multiply operator.
        Overrides:
        matchesNumberContext in class PrototypeObjectType

      • matchesObjectContext

        public final boolean matchesObjectContext()
        Description copied from class: JSType
        This predicate is used to test whether a given type can appear in an Object context, such as the expression in a with statement. Most types we will encounter, except notably null, have at least the potential for converting to Object. Host defined objects can get peculiar.
        Overrides:
        matchesObjectContext in class PrototypeObjectType

      • matchesStringContext

        public final boolean matchesStringContext()
        Description copied from class: JSType
        This predicate is used to test whether a given type can appear in a String context, such as an operand of a string concat (+) operator. All types have at least the potential for converting to String. When we add externally defined types, such as a browser OM, we may choose to add types that do not automatically convert to String.
        Overrides:
        matchesStringContext in class PrototypeObjectType

      • matchesSymbolContext

        public final boolean matchesSymbolContext()
        Description copied from class: JSType
        This predicate is used to test whether a given type can appear in a symbol context such as property access.
        Overrides:
        matchesSymbolContext in class PrototypeObjectType

      • removeProperty

        public final boolean removeProperty​(java.lang.String name)
        Description copied from class: ObjectType
        Removes the declared or inferred property from this ObjectType.
        Overrides:
        removeProperty in class PrototypeObjectType
        Parameters:
        name - the property's name
        Returns:
        true if the property was removed successfully. False if the property did not exist, or could not be removed.

      • setPropertyJSDocInfo

        public final void setPropertyJSDocInfo​(java.lang.String propertyName,
                                       JSDocInfo info)
        Description copied from class: ObjectType
        Sets the docInfo for the specified property from the JSDocInfo on its definition.
        Overrides:
        setPropertyJSDocInfo in class PrototypeObjectType
        info - JSDocInfo for the property definition. May be null.

      • visit

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

      • getConstructor

        public final FunctionType getConstructor()
        Description copied from class: ObjectType
        Gets this object's constructor.
        Overrides:
        getConstructor in class FunctionType
        Returns:
        this object's constructor or null if it is a native object (constructed natively v.s. by instantiation of a function)