Package com.google.javascript.rhino.jstype

Class UnknownType

java.lang.Object
com.google.javascript.rhino.jstype.JSType
com.google.javascript.rhino.jstype.ObjectType
com.google.javascript.rhino.jstype.UnknownType
public final class UnknownType extends ObjectType
The Unknown type.

  • Method Details

    • 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

    • isCheckedUnknownType

      public boolean isCheckedUnknownType()
      Overrides:
      isCheckedUnknownType in class JSType

    • 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 Tri testForEquality(JSType that)
      Description copied from class: JSType
      Compares this and that.
      Overrides:
      testForEquality in class ObjectType
      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

    • 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:

    • getImplicitPrototype

      public @Nullable ObjectType getImplicitPrototype()
      Description copied from class: ObjectType
      Gets the implicit prototype (a.k.a. the [[Prototype]] property).
      Specified by:
      getImplicitPrototype in class ObjectType

    • getConstructor

      public @Nullable 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 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 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