Package daikon.inv.binary.twoScalar

Class TwoScalar

Object

Invariant

BinaryInvariant

TwoScalar

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

IntEqual, IntGreaterEqual, IntGreaterThan, IntLessEqual, IntLessThan, IntNonEqual, LinearBinary, NumericInt

public abstract class TwoScalar
extends BinaryInvariant

Base class for invariants over two variables of type long. An example is y = abs(x).

Provides a simpler mechanism for non-symmetric invariants to function over both permutations of their variables.

Non-symmetric invariants must instantiate two objects (one for each argument order). This is tracked by the variable swap. They must always access their variables via the methods var1() and var2() which return the correct variable (based on the swap setting). No other work is necessary, all permuations and resurrection is handled here.

Symmetric invariants should define symmetric() to return true or override resurrect_done_swapped to do nothing. Non-symmetric invariants that use converse operations (eg, less than and greater than) rather than argument swapping should override resurrect_done_swapped to return the correct class.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class Invariant

Invariant.ClassVarnameComparator, Invariant.ClassVarnameFormulaComparator, Invariant.InvariantComparatorForPrinting, Invariant.Match

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	swap

Fields inherited from class Invariant

CONFIDENCE_JUSTIFIED, CONFIDENCE_NEVER, CONFIDENCE_UNJUSTIFIED, debug, debugFlow, debugGuarding, debugIsObvious, debugIsWorthPrinting, debugPrint, debugPrintEquality, dkconfig_confidence_limit, dkconfig_fuzzy_ratio, dkconfig_simplify_define_predicates, falsified, invariantEnabledDefault, isGuardingPredicate, min_mod_non_missing_samples, ppt, PROBABILITY_JUSTIFIED, PROBABILITY_NEVER, PROBABILITY_UNJUSTIFIED

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TwoScalar()
protected	TwoScalar(PptSlice ppt)

Method Summary

Modifier and Type	Method	Description
InvariantStatus	add(@Interned Object val1, @Interned Object val2, int mod_index, int count)
InvariantStatus	add_modified(long v1, long v2, int count)	Default implementation simply calls check.
InvariantStatus	add_unmodified(long v1, long v2, int count)	By default, do nothing if the value hasn't been seen yet.
InvariantStatus	check(@Interned Object val1, @Interned Object val2, int mod_index, int count)
abstract InvariantStatus	check_modified(long v1, long v2, int count)	Presents a sample to the invariant.
InvariantStatus	check_unmodified(long v1, long v2, int count)
protected double	computeConfidence()	This method computes the confidence that this invariant occurred by chance.
boolean	get_swap()	Returns whether or not the variable order is currently swapped for this invariant.
boolean	isSameFormula(Invariant other)	Return true if both invariants are the same class and the order of the variables (swap) is the same.
String	repr()	Returns a representation of the class.
protected Invariant	resurrect_done(int[] permutation)	Checks to see if the variable order was swapped and calls the correct routine to handle it.
protected Invariant	resurrect_done_swapped()	Swaps the variables by inverting the state of swap.
protected Invariant	resurrect_done_unswapped()	Subclasses can override in the rare cases they need to fix things even when not swapped.
boolean	valid_types(VarInfo[] vis)	Returns whether or not the specified types are valid.
VarInfo	var1()	Returns the first variable.
VarInfo	var1(VarInfo[] vis)	Returns the first variable from the specified vis.
VarInfo	var2()	Returns the first variable.
VarInfo	var2(VarInfo[] vis)	Returns the first variable in the specified vis.

Methods inherited from class BinaryInvariant

add_unordered, check_unordered, find, is_symmetric

Methods inherited from class Invariant

add_sample, asInvClass, checkRep, clear_falsified, clone, clone_and_permute, conf_is_ge, confidence_and, confidence_and, confidence_or, createGuardedInvariant, createGuardingPredicate, enabled, enoughSamples, falsify, find, format, format_classname, format_too_few_samples, format_unimplemented, format_using, formatFuzzy, get_comparability, get_ni_suppressions, getConfidence, getGuardingList, getGuardingList, hasUninterestingConstant, instantiate, instantiate_dyn, instantiate_ok, is_false, is_ni_suppressed, isActive, isAllPrestate, isEqualityComparison, isExact, isExclusiveFormula, isObvious, isObviousDynamically, isObviousDynamically, isObviousDynamically_SomeInEquality, isObviousDynamically_SomeInEqualityHelper, isObviousStatically, isObviousStatically, isObviousStatically_AllInEquality, isObviousStatically_SomeInEquality, isObviousStatically_SomeInEqualityHelper, isReflexive, isSameInvariant, isValidEscExpression, isValidExpression, isWorthPrinting, justified, log, log, logDetail, logOn, match, merge, mergeFormulasOk, permute, prob_and, prob_and, prob_is_ge, prob_or, repCheck, repr_prob, resurrect, simplify_format_double, simplify_format_long, simplify_format_string, state_match, toString, toString, transfer, usesVar, usesVar, usesVarDerived, varNames

Methods inherited from class Object

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

Field Detail

swap

protected boolean swap

Constructor Detail

TwoScalar

protected TwoScalar(PptSlice ppt)

TwoScalar

protected TwoScalar()

Method Detail

valid_types

public final boolean valid_types(VarInfo[] vis)

Returns whether or not the specified types are valid.

Specified by:

valid_types in class Invariant

See Also:

Invariant.instantiate_ok(VarInfo[])

get_swap

public boolean get_swap()

Returns whether or not the variable order is currently swapped for this invariant.

Overrides:

get_swap in class BinaryInvariant

resurrect_done

protected Invariant resurrect_done(int[] permutation)

Checks to see if the variable order was swapped and calls the correct routine to handle it.

Specified by:

resurrect_done in class Invariant

Parameters:

permutation - the permutation

Returns:

the permuted invariant

resurrect_done_swapped

protected Invariant resurrect_done_swapped()

Swaps the variables by inverting the state of swap.

resurrect_done_unswapped

protected Invariant resurrect_done_unswapped()

Subclasses can override in the rare cases they need to fix things even when not swapped.

var1

public VarInfo var1(@GuardSatisfied TwoScalar this)

Returns the first variable. This is the only mechanism by which subclasses should access variables.

var2

public VarInfo var2(@GuardSatisfied TwoScalar this)

Returns the first variable. This is the only mechanism by which subclasses should access variables.

var1

public VarInfo var1(VarInfo[] vis)

Returns the first variable from the specified vis. This is the only mechanism by which subclasses should access variables.

var2

public VarInfo var2(VarInfo[] vis)

Returns the first variable in the specified vis. This is the only mechanism by which subclasses should access variables.

check

public InvariantStatus check(@Interned Object val1,
                             @Interned Object val2,
                             int mod_index,
                             int count)

Specified by:

check in class BinaryInvariant

add

public InvariantStatus add(@Interned Object val1,
                           @Interned Object val2,
                           int mod_index,
                           int count)

Specified by:

add in class BinaryInvariant

check_modified

public abstract InvariantStatus check_modified(long v1,
                                               long v2,
                                               int count)

Presents a sample to the invariant. Returns whether the sample is consistent with the invariant. Does not change the state of the invariant.

Parameters:

count - how many identical samples were observed in a row. For example, three calls to check_modified with a count parameter of 1 is equivalent to one call to check_modified with a count parameter of 3.

Returns:

whether or not the sample is consistent with the invariant

check_unmodified

public InvariantStatus check_unmodified(long v1,
                                        long v2,
                                        int count)

add_modified

public InvariantStatus add_modified(long v1,
                                    long v2,
                                    int count)

Default implementation simply calls check. Subclasses can override.

add_unmodified

public InvariantStatus add_unmodified(long v1,
                                      long v2,
                                      int count)

By default, do nothing if the value hasn't been seen yet. Subclasses can override this.

repr

public String repr(@GuardSatisfied TwoScalar this)

Returns a representation of the class. This includes the classname, variables, and swap state.

Overrides:

repr in class Invariant

Returns:

a string representation of this

isSameFormula

@Pure
public boolean isSameFormula(Invariant other)

Return true if both invariants are the same class and the order of the variables (swap) is the same.

Specified by:

isSameFormula in class Invariant

Parameters:

other - the invariant to compare to this one

Returns:

true iff the two invariants represent the same mathematical formula. Does not consider

computeConfidence

protected double computeConfidence()

Description copied from class: Invariant

This method computes the confidence that this invariant occurred by chance. Clients should call Invariant.getConfidence() instead.

This method need not check the value of field "falsified", as the caller does that.

Specified by:

computeConfidence in class Invariant

Returns:

confidence of this invariant

See Also:

Invariant.getConfidence()