Package com.google.javascript.rhino.jstype

Class UnknownType

  • All Implemented Interfaces:
    java.io.Serializable
    public class UnknownType
extends ObjectType
    The Unknown type.
    See Also:
    Serialized Form

    • Method Detail

      • isUnknownType

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

      • canBeCalled

        public boolean canBeCalled()
        Description copied from class: JSType
        This predicate is used to test whether a given type can be used as the 'function' in a function call.
        Overrides:
        canBeCalled in class JSType
        Returns:
        true if this type might be callable.

      • matchesNumberContext

        public 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 JSType

      • matchesObjectContext

        public 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 JSType

      • matchesStringContext

        public 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 JSType

      • matchesSymbolContext

        public 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 JSType

      • testForEquality

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

      • isNullable

        public boolean isNullable()
        Description copied from class: JSType
        Tests whether this type is nullable.
        Overrides:
        isNullable in class JSType

      • isVoidable

        public boolean isVoidable()
        Description copied from class: JSType
        Tests whether this type is voidable.
        Overrides:
        isVoidable in class JSType

      • visit

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

      • getConstructor

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

      • 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)

        Specified by:
        getReferenceName in class ObjectType
        Returns:
        the object's name or null if this is an anonymous object

      • getDisplayName

        public java.lang.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 ObjectType
        Returns:
        the display name of the type, or null if one is not available

      • hasDisplayName

        public boolean hasDisplayName()
        Overrides:
        hasDisplayName in class JSType
        Returns:
        true if the JSType has a user meaningful label.

      • 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}
        Overrides:
        getPossibleToBooleanOutcomes in class ObjectType
        Returns:
        the set of boolean literals for this type