com.google.javascript.rhino.jstype
Class UnknownType

java.lang.Object
  extended by com.google.javascript.rhino.jstype.JSType
      extended by com.google.javascript.rhino.jstype.ObjectType
          extended by com.google.javascript.rhino.jstype.UnknownType
All Implemented Interfaces:
StaticScope<JSType>, Serializable

public class UnknownType
extends ObjectType

The Unknown type.

See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class com.google.javascript.rhino.jstype.ObjectType
ObjectType.Property
 
Nested classes/interfaces inherited from class com.google.javascript.rhino.jstype.JSType
JSType.TypePair
 
Field Summary
 
Fields inherited from class com.google.javascript.rhino.jstype.JSType
EMPTY_TYPE_COMPONENT, ENUMDECL, NOT_A_CLASS, NOT_A_TYPE, NOT_ENUMDECL, UNKNOWN_NAME
 
Method Summary
 boolean canAssignTo(JSType that)
          Tests whether values of this type can be safely assigned to values of that type.
 boolean canBeCalled()
          This predicate is used to test whether a given type can be used as the 'function' in a function call.
 FunctionType getConstructor()
          Gets this object's constructor.
 String getDisplayName()
          Returns a user meaningful label for the JSType instance.
 ObjectType getImplicitPrototype()
          Gets the implicit prototype (a.k.a.
 BooleanLiteralSet getPossibleToBooleanOutcomes()
          Computes the set of possible outcomes of the ToBoolean predicate for this type.
 int getPropertiesCount()
          Gets the number of properties of this object.
 JSType getPropertyType(String propertyName)
          Gets the property type of the property whose name is given.
 String getReferenceName()
          Gets the reference name for this object.
 ObjectType.Property getSlot(String name)
          Returns any defined slot within this scope for this name.
 boolean hasDisplayName()
           
 boolean hasProperty(String propertyName)
          Checks whether the property whose name is given is present on the object.
 boolean isCheckedUnknownType()
           
 boolean isNullable()
          Tests whether this type is nullable.
 boolean isPropertyTypeDeclared(String propertyName)
          Checks whether the property's type is declared.
 boolean isPropertyTypeInferred(String propertyName)
          Checks whether the property's type is inferred.
 boolean isSubtype(JSType that)
          Checks whether this is a subtype of that.
 boolean isUnknownType()
          We treat this as the unknown type if any of its implicit prototype properties is unknown.
 boolean matchesNumberContext()
          This predicate is used to test whether a given type can appear in a numeric context, such as an operand of a multiply operator.
 boolean matchesObjectContext()
          This predicate is used to test whether a given type can appear in an Object context, such as the expression in a with statement.
 boolean matchesStringContext()
          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.
 TernaryValue testForEquality(JSType that)
          Compares this and that.
<T> T
visit(Visitor<T> visitor)
          Visit this type with the given visitor.
 
Methods inherited from class com.google.javascript.rhino.jstype.ObjectType
cast, clearCachedValues, createDelegateSuffix, defineDeclaredProperty, defineInferredProperty, findPropertyType, getCtorExtendedInterfaces, getCtorImplementedInterfaces, getIndexType, getJSDocInfo, getNormalizedReferenceName, getOwnerFunction, getOwnPropertyJSDocInfo, getOwnPropertyNames, getOwnSlot, getParameterType, getParentScope, getPropertyNames, getPropertyNode, getRootNode, getTypeOfThis, hasCachedValues, hasOwnProperty, hasReferenceName, isFunctionPrototypeType, isNativeObjectType, isObject, isPropertyInExterns, removeProperty, setJSDocInfo, setPropertyJSDocInfo
 
Methods inherited from class com.google.javascript.rhino.jstype.JSType
autobox, autoboxesTo, canTestForEqualityWith, canTestForShallowEqualityWith, clearResolved, collapseUnion, dereference, differsFrom, equals, forceResolve, getGreatestSubtype, getLeastSupertype, getRestrictedTypeGivenToBooleanOutcome, getTypesUnderEquality, getTypesUnderInequality, getTypesUnderShallowEquality, getTypesUnderShallowInequality, hashCode, isAllType, isArrayType, isBooleanObjectType, isBooleanValueType, isConstructor, isDateType, isEmptyType, isEnumElementType, isEnumType, isEquivalent, isEquivalentTo, isFunctionType, isGlobalThisType, isInstanceType, isInterface, isNominalConstructor, isNominalType, isNoObjectType, isNoResolvedType, isNoType, isNullType, isNumber, isNumberObjectType, isNumberValueType, isOrdinaryFunction, isRecordType, isRegexpType, isResolved, isString, isStringObjectType, isStringValueType, isTemplateType, isUnionType, isVoidType, matchConstraint, matchesInt32Context, matchesUint32Context, resolve, restrictByNotNullOrUndefined, setValidator, toAnnotationString, toDebugHashCodeString, toMaybeEnumElementType, toMaybeEnumType, toMaybeFunctionType, toMaybeFunctionType, toMaybeUnionType, toObjectType, toString, unboxesTo
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Method Detail

getSlot

public ObjectType.Property getSlot(String name)
Description copied from interface: StaticScope
Returns any defined slot within this scope for this name. This call continues searching through parent scopes if a slot with this name is not found in the current scope.

Specified by:
getSlot in interface StaticScope<JSType>
Specified by:
getSlot in class ObjectType
Parameters:
name - The name of the variable slot to look up.
Returns:
The defined slot for the variable, or null if no definition exists.

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

canAssignTo

public boolean canAssignTo(JSType that)
Description copied from class: JSType
Tests whether values of this type can be safely assigned to values of that type.

The default implementation verifies that this is a subtype of that.

Overrides:
canAssignTo 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

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

isSubtype

public boolean isSubtype(JSType that)
Description copied from class: JSType
Checks whether this is a subtype of that.

Subtyping rules:

Overrides:
isSubtype in class JSType
Returns:
this &lt;: that

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

getImplicitPrototype

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

Specified by:
getImplicitPrototype in class ObjectType

getPropertiesCount

public int getPropertiesCount()
Description copied from class: ObjectType
Gets the number of properties of this object.

Specified by:
getPropertiesCount in class ObjectType

getPropertyType

public JSType getPropertyType(String propertyName)
Description copied from class: ObjectType
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.

Specified by:
getPropertyType in class ObjectType
Returns:
the property's type or UnknownType. This method never returns null.

hasProperty

public boolean hasProperty(String propertyName)
Description copied from class: ObjectType
Checks whether the property whose name is given is present on the object.

Specified by:
hasProperty in class ObjectType

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 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.

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.

isPropertyTypeDeclared

public boolean isPropertyTypeDeclared(String propertyName)
Description copied from class: ObjectType
Checks whether the property's type is declared.

Specified by:
isPropertyTypeDeclared in class ObjectType

isPropertyTypeInferred

public boolean isPropertyTypeInferred(String propertyName)
Description copied from class: ObjectType
Checks whether the property's type is inferred.

Specified by:
isPropertyTypeInferred in class ObjectType

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