Package daikon

Class VarComparability

Object

VarComparability

Direct Known Subclasses:

VarComparabilityImplicit, VarComparabilityNone

public abstract class VarComparability
extends Object

Represents the comparability of variables, including methods to determine if two VarComparabilities are comparable. VarComparability types have two formats: implicit and none.

A VarComparabilityImplicit is an arbitrary string, and comparisons succeed exactly if the two VarComparabilitys are identical.

VarComparabilityNone means no comparability information was provided.

Field Summary

Fields

Modifier and Type	Field	Description
static Logger	debug	Debug tracer.
static int	IMPLICIT
static int	NONE

Constructor Summary

Constructors

Constructor	Description
VarComparability()

Method Summary

Modifier and Type	Method	Description
abstract boolean	alwaysComparable()	Returns true if this is comparable to everything else.
static boolean	comparable(@GuardSatisfied VarComparability type1, @GuardSatisfied VarComparability type2)	Returns whether two comparabilities are comparable.
static boolean	comparable(VarInfo v1, VarInfo v2)	Returns whether two variables are comparable.
abstract VarComparability	elementType()
boolean	equality_set_ok(@GuardSatisfied VarComparability other)	In general, if two items are comparable, they can be placed in the same equality set.
abstract VarComparability	indexType(int dim)
abstract VarComparability	makeAlias()
static VarComparability	makeAlias(VarInfo vi)
static VarComparability	makeComparabilitySameIndices(String elemTypeName, VarComparability old)	Create a VarComparability based on comparabilities of indices.
static VarComparability	parse(int format, String rep, ProglangType vartype)	Create a VarComparability representing the given arguments with respect to a variable.
abstract VarComparability	string_length_type()	Return the comparability for the length of this string*

Methods inherited from class Object

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

Field Detail

debug

public static final Logger debug

Debug tracer.

NONE

public static final int NONE

See Also:

Constant Field Values

IMPLICIT

public static final int IMPLICIT

See Also:

Constant Field Values

Constructor Detail

VarComparability

public VarComparability()

Method Detail

parse

public static VarComparability parse(int format,
                                     String rep,
                                     ProglangType vartype)

Create a VarComparability representing the given arguments with respect to a variable.

Parameters:

format - the type of comparability, either NONE or IMPLICIT

rep - a regular expression indicating how to match. The form is "(a)[b][c]..." where each variable is string (or number) that is a UID for a basic type. a is the type of the element, b is the type of the first index, c the type of the second, etc. Index variables only apply if this is an array.

vartype - the declared type of the variable

makeComparabilitySameIndices

public static VarComparability makeComparabilitySameIndices(String elemTypeName,
                                                            VarComparability old)

Create a VarComparability based on comparabilities of indices.

Parameters:

elemTypeName - the new type of the elements of return value

old - the varcomparability that this is derived from; has the same indices as this

Returns:

a new comparability that is an array with the same dimensionality and indices as given, but with a different element type

makeAlias

public static VarComparability makeAlias(VarInfo vi)

makeAlias

public abstract VarComparability makeAlias()

elementType

public abstract VarComparability elementType(@GuardSatisfied VarComparability this)

indexType

public abstract VarComparability indexType(@GuardSatisfied VarComparability this,
                                           int dim)

string_length_type

public abstract VarComparability string_length_type()

Return the comparability for the length of this string*

alwaysComparable

public abstract boolean alwaysComparable(@GuardSatisfied VarComparability this)

Returns true if this is comparable to everything else.

comparable

@Pure
public static boolean comparable(VarInfo v1,
                                 VarInfo v2)

Returns whether two variables are comparable.

comparable

@Pure
public static boolean comparable(@GuardSatisfied VarComparability type1,
                                 @GuardSatisfied VarComparability type2)

Returns whether two comparabilities are comparable.

equality_set_ok

public boolean equality_set_ok(@GuardSatisfied VarComparability this,
                               @GuardSatisfied VarComparability other)

In general, if two items are comparable, they can be placed in the same equality set. This is not always true for some comparabilities (because they are not always transitive). They can override this method to provide the correct results.