Package com.google.javascript.rhino.jstype

Class NoType

java.lang.Object
com.google.javascript.rhino.jstype.JSType
com.google.javascript.rhino.jstype.ObjectType
com.google.javascript.rhino.jstype.FunctionType
com.google.javascript.rhino.jstype.NoObjectType
com.google.javascript.rhino.jstype.NoType
All Implemented Interfaces:
StaticScope<JSType>, Serializable
public class NoType extends NoObjectType
Bottom type, representing the subclass of any value or object. Although JavaScript programmers can't explicitly denote the bottom type, it comes up in static analysis. For example, if we have: var x = null; if (x) { f(x); } We need to be able to assign x a type within the f(x) call. Since it has no possible type, we assign x the NoType, so that f(x) is legal no matter what the type of f's first argument is.
See Also:

  • Method Details

    • isNoObjectType

      public boolean isNoObjectType()
      Overrides:
      isNoObjectType in class NoObjectType

    • isNoType

      public boolean isNoType()
      Overrides:
      isNoType in class JSType

    • isNullable

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

    • isSubtype

      public boolean isSubtype(JSType that)
      Description copied from class: FunctionType
      A function is a subtype of another if their call methods are related via subtyping and this is a subtype of that with regard to the prototype chain.
      Overrides:
      isSubtype in class NoObjectType
      Returns:
      this &lt;: that

    • 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:
      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

    • 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 NoObjectType

    • 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 NoObjectType

    • 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 NoObjectType

    • visit

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

    • unboxesTo

      public JSType unboxesTo()
      Description copied from class: JSType
      Turn an object type to its corresponding scalar type.
      Overrides:
      unboxesTo in class JSType
      Returns:
      the unboxed type or null if this type does not unbox.

    • hasReferenceName

      public boolean hasReferenceName()
      Description copied from class: ObjectType
      Returns true if the object is named.
      Overrides:
      hasReferenceName in class ObjectType
      Returns:
      true if the object is named, false if it is anonymous

    • isNativeObjectType

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

    • getOwnerFunction

      public FunctionType getOwnerFunction()
      Description copied from class: ObjectType
      Gets the owner of this if it's a function prototype.
      Overrides:
      getOwnerFunction in class ObjectType

    • getCtorImplementedInterfaces

      public Iterable<ObjectType> getCtorImplementedInterfaces()
      Description copied from class: ObjectType
      Gets the interfaces implemented by the ctor associated with this type. Intended to be overridden by subclasses.
      Overrides:
      getCtorImplementedInterfaces in class ObjectType

    • getCtorExtendedInterfaces

      public Iterable<ObjectType> getCtorExtendedInterfaces()
      Description copied from class: ObjectType
      Gets the interfaces extended by the interface associated with this type. Intended to be overridden by subclasses.
      Overrides:
      getCtorExtendedInterfaces in class ObjectType

    • matchConstraint

      public void matchConstraint(JSType constraint)
      Description copied from class: JSType
      Modify this type so that it matches the specified type. This is useful for reverse type-inference, where we want to infer that an object literal matches its constraint (much like how the java compiler does reverse-inference to figure out generics).
      Overrides:
      matchConstraint in class JSType

    • matchRecordTypeConstraint

      public void matchRecordTypeConstraint(ObjectType constraintObj)