gnu.kawa.reflect
Class OccurrenceType

java.lang.Object
  gnu.bytecode.Type
      gnu.bytecode.ObjectType
          gnu.kawa.reflect.OccurrenceType

All Implemented Interfaces:

TypeValue, java.io.Externalizable, java.io.Serializable

Direct Known Subclasses:

NodeSetType

public class OccurrenceType
extends ObjectType
implements java.io.Externalizable, TypeValue

A type that matches some number of repetitions of a basetype.

See Also:

Serialized Form

Field Summary

static Type	emptySequenceType
static ClassType	typeOccurrenceType

Fields inherited from class gnu.bytecode.ObjectType

flags

Fields inherited from class gnu.bytecode.Type

boolean_ctype, boolean_type, booleanValue_method, byte_type, char_type, clone_method, double_type, doubleValue_method, float_type, floatValue_method, int_type, intValue_method, java_lang_Class_type, long_type, longValue_method, neverReturnsType, nullType, number_type, pointer_type, reflectClass, short_type, string_type, throwable_type, toString_method, tostring_type, typeArray0, void_type

Constructor Summary

OccurrenceType(Type base, int minOccurs, int maxOccurs)

Method Summary

java.lang.Object	coerceFromObject(java.lang.Object obj) Convert an object to a value of this Type.
int	compare(Type other) Return a numeric code showing "subtype" relationship: 1: if other is a pure subtype of this; 0: if has the same values; -1: if this is a pure subtype of other; -2: if they have values in common but neither is a subtype of the other; -3: if the types have no values in common.
void	emitIsInstance(Variable incoming, Compilation comp, Target target) Emit code for incoming instanceof this_type.
void	emitTestIf(Variable incoming, Declaration decl, Compilation comp) Emit code for if (incoming instanceof this_type) decl = incoming ....
Type	getBase()
Procedure	getConstructor() Get the constructor function for this type.
Type	getImplementationType() The type used to implement types not natively understood by the JVM.
static Type	getInstance(Type base, int minOccurs, int maxOccurs)
boolean	isInstance(java.lang.Object obj)
static char	itemCountCode(Type type) Returna a quantifer kind for a sequence type.
static boolean	itemCountIsOne(Type type)
static boolean	itemCountIsZeroOrOne(Type type)
static int	itemCountRange(Type type) Return a conservative estimage on the min/max number of items of a type.
static Type	itemPrimeType(Type type) QUery formal semantics "prime type"
int	maxOccurs()
int	minOccurs()
void	readExternal(java.io.ObjectInput in)
java.lang.String	toString()
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class gnu.bytecode.ObjectType

emitCoerceFromObject, getInternalName, getMethods, getReflectClass, isExisting, promote, setExisting

Methods inherited from class gnu.bytecode.Type

coerceToObject, emitCoerceToObject, emitIsInstance, getName, getSignature, getSize, getSizeInWords, getType, hashCode, isMoreSpecific, isSubtype, isValidJavaTypeName, isVoid, lookupType, lowestCommonSuperType, make, registerTypeForClass, setName, setReflectClass, setSignature, signatureLength, signatureLength, signatureToName, signatureToPrimitive, signatureToType, signatureToType, swappedCompareResult

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

emptySequenceType

public static final Type emptySequenceType

typeOccurrenceType

public static final ClassType typeOccurrenceType

Constructor Detail

OccurrenceType

public OccurrenceType(Type base,
                      int minOccurs,
                      int maxOccurs)

Method Detail

getBase

public Type getBase()

minOccurs

public int minOccurs()

maxOccurs

public int maxOccurs()

getInstance

public static Type getInstance(Type base,
                               int minOccurs,
                               int maxOccurs)

getImplementationType

public Type getImplementationType()

Description copied from class: Type

The type used to implement types not natively understood by the JVM. Usually, the identity function. However, a language might handle union types or template types or type expressions calculated at run time. In that case return the type used at the JVM level, and known at compile time.

Specified by:

getImplementationType in interface TypeValue

Overrides:

getImplementationType in class ObjectType

compare

public int compare(Type other)

Description copied from class: Type

Return a numeric code showing "subtype" relationship: 1: if other is a pure subtype of this; 0: if has the same values; -1: if this is a pure subtype of other; -2: if they have values in common but neither is a subtype of the other; -3: if the types have no values in common. "Same member" is rather loose; by "A is a subtype of B" we mean that all instance of A can be "widened" to B. More formally, A.compare(B) returns: 1: all B values can be converted to A without a coercion failure (i.e. a ClassCastException or overflow or major loss of information), but not vice versa. 0: all A values can be converted to B without a coercion failure and vice versa; -1: all A values can be converted to B without a coercion failure not not vice versa; -2: there are (potentially) some A values that can be converted to B, and some B values can be converted to A; -3: there are no A values that can be converted to B, and neither are there any B values that can be converted to A.

Overrides:

compare in class ObjectType

coerceFromObject

public java.lang.Object coerceFromObject(java.lang.Object obj)

Description copied from class: ObjectType

Convert an object to a value of this Type. Throw a ClassCastException when this is not possible.

Overrides:

coerceFromObject in class ObjectType

isInstance

public boolean isInstance(java.lang.Object obj)

Overrides:

isInstance in class ObjectType

emitTestIf

public void emitTestIf(Variable incoming,
                       Declaration decl,
                       Compilation comp)

Description copied from interface: TypeValue

Emit code for if (incoming instanceof this_type) decl = incoming .... This method is designed for typeswitch applications, where this call is the first part of a conditional, so it must be followed by calls to emitElse and emitFi.

Specified by:

emitTestIf in interface TypeValue

Parameters:

incoming - Contains the value we are testing to see if it has the type of this. If null, use top-of-stack. May not be null if incoming is non-null.

decl - If non-null, assign value after coercion to Declaration.

comp - The compilation state.

emitIsInstance

public void emitIsInstance(Variable incoming,
                           Compilation comp,
                           Target target)

Description copied from interface: TypeValue

Emit code for incoming instanceof this_type. The implementation can use InstanceOf .emitIsInstance which is a conveniece method that calls emitTestIf.

Specified by:

emitIsInstance in interface TypeValue

Parameters:

incoming - Contains the value we are testing to see if it has the the type of 'this'. If null, use top-of-stack.

comp - The compilation state.

target - Where to leave the result.

getConstructor

public Procedure getConstructor()

Description copied from interface: TypeValue

Get the constructor function for this type. Returns null if there is no contructor function. Also returns null if this extends ClassType or ArrayType and standard Java constructors ( methods) should be used.

Specified by:

getConstructor in interface TypeValue

itemCountRange

public static int itemCountRange(Type type)

Return a conservative estimage on the min/max number of items of a type.

Returns:

maxCount << 12 | minCount & 0xFFF, where a maxCount of -1 means unbounded.

itemCountCode

public static char itemCountCode(Type type)

Returna a quantifer kind for a sequence type.

Returns:

'0' if type is known to be a void (0-item) type; '1' if type is known to be a single-item type; '?' if type matches a sequence of 0 or 1 items; '+' if type matches a sequence of 1 or more items; '*' otherwise.

itemCountIsZeroOrOne

public static boolean itemCountIsZeroOrOne(Type type)

itemCountIsOne

public static boolean itemCountIsOne(Type type)

itemPrimeType

public static Type itemPrimeType(Type type)

QUery formal semantics "prime type"

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException

toString

public java.lang.String toString()

Overrides:

toString in class Type

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

java.lang.ClassNotFoundException