gov.nasa.arc.brahms.vm.data
Class VMOperand

java.lang.Object
  gov.nasa.arc.brahms.common.data.BrahmsObject
      gov.nasa.arc.brahms.common.data.Operand
          gov.nasa.arc.brahms.vm.data.VMOperand

All Implemented Interfaces:

IAssignmentLhs, gov.nasa.arc.brahms.common.IConstants, IVMAssignmentLhs, java.io.Serializable

public class VMOperand
extends Operand
implements IVMAssignmentLhs

A VMOperand is an Operand with extensions for use in the virtual machine. An operand represents a terminal element in an expression and specifies either an object, object and attribute, value, or represents a nested expression. An object can be one of a Concept, Current, Variable referencing a Concept, or a Parameter referencing a Concept or Variable. A value can be an Integer, Double, Boolean, String, Symbol, a Variable referencing a value or a Parameter referencing a value.

Version:

$Revision: 1.11 $ $Date: 2009/11/23 22:24:32 $ $Author: rnado $

Author:

Ron van Hoof

See Also:

Operand, Serialized Form

Field Summary

Fields inherited from interface gov.nasa.arc.brahms.common.IConstants

ABORT, ACTIVECLASS, ACTIVECONCEPT, ACTIVEINSTANCE, AGENT, ANONYMOUS, ANYAGENT, AREA, AREADEF, ASSIGNED, ATTRIBUTE, BASEAREADEF, BASECLASS, BASECONCEPTUALCLASS, BASEGROUP, BASELIBRARY, BOOLEAN, BROADCAST, BUILDING, BYTE, CCLOCK, CDATE, CHAR, CITY, CLASS, CLOCK, COLLECTALL, COMMUNICATE, COMPLETE, COMPOSITE, COMPUTER, CONCEPT, CONCEPTUALCLASS, CONCEPTUALCONCEPT, CONCEPTUALOBJECT, CONTINUE, COPY, CREATEAGENT, CREATEAREA, CREATEOBJECT, current, CURRENT, DATAFRAME, DATE, DB, DETECTABLE, DIV, DOUBLE, EMAIL, EMPTY_STRING, END, ENDACTIVITY, ENTAGENT, EQ, EXCEPTION, EXPR, FACE2FACE, FACTFRAME, FALSE, FAX, FLOAT, FOREACH, FORONE, G2, GE, GEOGRAPHYCONCEPT, GESTURE, GET, GROUP, GT, IMPASSE, INT, INVALID, JAVA, JAVA_TYPE, KNOWN_MODIFIER, KNOWNVAL_MODIFIER, LE, LOCAL, LONG, LT, MAP, MINUS, MOD, MOVE, MULT, NE, NEW, NONE, NOT_MODIFIER, NOWORK, O, OA, OBJECT, ONTOLOGY, PAGER, PARAMETER, PATH, PHONE, PLUS, PRIMITIVE, PRIVATE, PROAGENT, PROTECTED, PRSAGENT, PUBLIC, PUT, RECEIVE, RELATION, sACTIVECLASS, sACTIVECONCEPT, sACTIVEINSTANCE, sAGENT, sARCHIVE, sAREA, sAREADEF, sBOOLEAN, sBYTE, sBYTECODEEXT, sCHAR, sCLASS, sCOMPUTER, sCONCEPT, sCONCEPTUALCLASS, sCONCEPTUALCONCEPT, sCONCEPTUALOBJECT, sCOPY, sCURRENT, sDETECTABLE, sDOUBLE, sEMAIL, sEND, SEND, sFACE2FACE, sFAX, sFILEEXT, sFLOAT, sGEOGRAPHYCONCEPT, sGROUP, SHORT, SIMAGENT, sINT, sJAVA_TYPE, sLONG, sMAP, sNEW, sNONE, sNOWORK, sOBJECT, SOURCECODE, sPAGER, sPARAMETER, sPATH, sPHONE, sPRIVATE, sPROJECTEXT, sPROTECTED, sPUBLIC, sSHORT, sSTART, sSTRING, sSYMBOL, START, STRING, sUNKNOWN, sVOID, SYMBOL, TRUE, UDT, UML, UNASSIGNED, UNDEFINED, unknown, UNKNOWN, UNKNOWN_MODIFIER, V, VARIABLE, VOID, WHENEVER, WORKFRAME, WORLD, XML

Constructor Summary

VMOperand()
Constructor, creates a new empty operand.

VMOperand(java.lang.Boolean b)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Byte bt)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Character c)
Constructor, creates a new operand referencing the specified value

VMOperand(Concept concept)
Constructor, creates a new operand for the specified concept.

VMOperand(Concept concept, Attribute attribute)
Constructor, creates a new operand for the specified concept and attribute

VMOperand(Current current)
Constructor, creates a new operand for the current indicator.

VMOperand(Current current, Attribute attribute)
Constructor, creates a new operand for the current indicator and attribute.

VMOperand(java.lang.Double d)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Float f)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Integer i)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Long l)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Object value)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.Object object, Attribute property)
Constructor, creates a new operand referencing the specified Java object and property.

VMOperand(Parameter parm)
Constructor, creates a new operand for the specified parameter.

VMOperand(Parameter parm, Attribute attribute)
Constructor, creates a new operand for the specified parameter and attribute.

VMOperand(java.lang.Short st)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.String s)
Constructor, creates a new operand referencing the specified value

VMOperand(java.lang.String s, boolean symbol)
Constructor, creates a new operand referencing the specified value

VMOperand(Variable var)
Constructor, creates a new operand for the specified variable.

VMOperand(Variable var, Attribute attribute)
Constructor, creates a new operand for the specified variable and attribute.

VMOperand(VMExpression expr)
Constructor, creates a new operand representing a nested expression

Method Summary

void	assign(java.util.List<java.lang.Object> values, VMActiveInstanceCtx agent, VMFrameCtx frame, Type collectType) Assigns a list of values to the element resulting from evaluating the left-hand side expression.
void	buildRSN(gov.nasa.arc.brahms.vm.engine.rsn.ReasoningStateNetwork rsn, gov.nasa.arc.brahms.vm.engine.rsn.IRSNFrameNode frame, gov.nasa.arc.brahms.vm.engine.rsn.RSNActivityRefNode actref, int modifier) Adds this operand to the reasoning state network to build up a reasoning state network that maintains a state of what statements matched with the operand.
java.lang.Object	coerceValue(java.lang.Object value, Type brahmsType) Attempts to coerce a value to a form that can be assigned to a variable of a given Brahms type.
boolean	evaluate(gov.nasa.arc.brahms.vm.engine.rsn.RSNFrameNode frame, int modifier, int relop, gov.nasa.arc.brahms.vm.engine.rsn.RSNFrameNode.FrameEvaluationRecord evalRcd, java.util.LinkedList values) Evaluates the operand as part of a precondition determining whether or not the operand has a successfull match with a statement.
java.lang.String	getConditionElementID(gov.nasa.arc.brahms.vm.engine.rsn.IRSNFrameNode frame) Returns the condition element id for this operand for the specified frame node.
java.util.LinkedList	resolveAsLhs(VMActiveInstanceCtx agent, VMFrameCtx frame, int strategy) Resolves this operand considering it to be part of an expression located on the left hand side in a comparison.
java.util.LinkedList	resolveAsRhs(VMActiveInstanceCtx agent, VMFrameCtx frame, int strategy) Resolves this operand considering it to be part of an expression located on the right hand side in a comparison.
java.util.LinkedList	resolveCollectionIndex(VMActiveInstanceCtx agent, VMFrameCtx frame) Resolves the collection index of this operand, this method resolves the index value specified in this operand.
java.util.LinkedList	resolveObject(VMActiveInstanceCtx agent, VMFrameCtx frame) Resolves the object for this operand to one or more concepts provided this operand represents an object.
java.util.LinkedList	resolveValue(VMActiveInstanceCtx agent, VMFrameCtx frame) Resolves the value of this operand, this method only resolves the object to the appropriate set of concepts or returns the value represented by this operand.

Methods inherited from class gov.nasa.arc.brahms.common.data.Operand

getAttribute, getCollectionIndex, getCollectionIndexType, getExpression, getObject, getObjectType, getOperandType, getParameters, getValue, getValueType, getValueTypeIndicator, getVariables, isAnonymous, isUnknown, setAttribute, setCollectionIndex, setCollectionIndex, setCollectionIndex, setCollectionIndex, setExpression, setID, setObject, setObject, setObject, setObject, setObjectType, setOperandType, setUnknown, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValueType, toString

Methods inherited from class gov.nasa.arc.brahms.common.data.BrahmsObject

delete, export, getFile, getID, getLine, getSerialNumber, isBCC, isDynamic, isLoaded, isResolved, setBCC, setDynamic, setFile, setID, setLine, setLoaded, setResolved, setSerialNumber

Methods inherited from class java.lang.Object

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

Methods inherited from interface gov.nasa.arc.brahms.common.data.IAssignmentLhs

export

Constructor Detail

VMOperand

public VMOperand()

Constructor, creates a new empty operand.

VMOperand

public VMOperand(Concept concept)

Constructor, creates a new operand for the specified concept.

Parameters:

concept - the Concept this operand references

VMOperand

public VMOperand(Current current)

Constructor, creates a new operand for the current indicator.

Parameters:

current - the Current object

VMOperand

public VMOperand(Variable var)

Constructor, creates a new operand for the specified variable.

Parameters:

var - the Variable this operand references

VMOperand

public VMOperand(Parameter parm)

Constructor, creates a new operand for the specified parameter.

Parameters:

parm - the Parameter this operand references

VMOperand

public VMOperand(Concept concept,
                 Attribute attribute)

Constructor, creates a new operand for the specified concept and attribute

Parameters:

concept - the Concept this operand references

attribute - the Attribute of the Concept referenced by the operand

VMOperand

public VMOperand(Current current,
                 Attribute attribute)

Constructor, creates a new operand for the current indicator and attribute.

Parameters:

current - the Current object

attribute - the Attribute of the Current concept referenced by the operand

VMOperand

public VMOperand(Variable var,
                 Attribute attribute)

Constructor, creates a new operand for the specified variable and attribute.

Parameters:

var - the Variable this operand references

attribute - the Attribute of the concept referenced by the variable as referenced by the operand

VMOperand

public VMOperand(Parameter parm,
                 Attribute attribute)

Constructor, creates a new operand for the specified parameter and attribute.

Parameters:

parm - the Parameter this operand references

attribute - the Attribute of the concept referenced by the parameter as referenced by the operand

VMOperand

public VMOperand(java.lang.Integer i)

Constructor, creates a new operand referencing the specified value

Parameters:

i - the Integer value referenced by the operand

VMOperand

public VMOperand(java.lang.Character c)

Constructor, creates a new operand referencing the specified value

Parameters:

c - the Character value referenced by the operand

VMOperand

public VMOperand(java.lang.Byte bt)

Constructor, creates a new operand referencing the specified value

Parameters:

bt - the Byte value referenced by the operand

VMOperand

public VMOperand(java.lang.Short st)

Constructor, creates a new operand referencing the specified value

Parameters:

st - the Short value referenced by the operand

VMOperand

public VMOperand(java.lang.Long l)

Constructor, creates a new operand referencing the specified value

Parameters:

l - the Long value referenced by the operand

VMOperand

public VMOperand(java.lang.Float f)

Constructor, creates a new operand referencing the specified value

Parameters:

f - the Float value referenced by the operand

VMOperand

public VMOperand(java.lang.Double d)

Constructor, creates a new operand referencing the specified value

Parameters:

d - the Double value referenced by the operand

VMOperand

public VMOperand(java.lang.Boolean b)

Constructor, creates a new operand referencing the specified value

Parameters:

b - the Boolean value referenced by the operand

VMOperand

public VMOperand(java.lang.String s)

Constructor, creates a new operand referencing the specified value

Parameters:

s - the String value referenced by the operand

VMOperand

public VMOperand(java.lang.String s,
                 boolean symbol)

Constructor, creates a new operand referencing the specified value

Parameters:

s - the String or Symbol value referenced by the operand

symbol - true if s is a symbol, false if s is a string

VMOperand

public VMOperand(java.lang.Object value)

Constructor, creates a new operand referencing the specified value

Parameters:

value - the Java object referenced by the operand

VMOperand

public VMOperand(java.lang.Object object,
                 Attribute property)

Constructor, creates a new operand referencing the specified Java object and property. This is only used for transfer definitions in a request for beliefs from a remote agent

Parameters:

object - the Java object referenced by the operand

property - an Attribute representing a property of the Java object

VMOperand

public VMOperand(VMExpression expr)

Constructor, creates a new operand representing a nested expression

Parameters:

expr - the nested Expression

Method Detail

resolveAsLhs

public java.util.LinkedList resolveAsLhs(VMActiveInstanceCtx agent,
                                         VMFrameCtx frame,
                                         int strategy)
                                  throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Resolves this operand considering it to be part of an expression located on the left hand side in a comparison. As an operand in a left hand side expression in a comparison the operand cannot contain a nested expression or a value. The operand resolves itself by checking the object. If the object is current, a variable, or a parameter they are resolved to concepts. This method returns one or more operands that can directly be used in expressions. If multiple concepts result from the resolution, then multiple operands are returned. If an attribute is specified, then all operands returned will also reference the attribute.

Note:This method is only usable with consequences, detectables, and transfer definitions, not with preconditions. Left hand side of preconditions can contain expressions which are not handled by this method.

Parameters:

agent - the agent from which the belief set is to be used to resolve this operand

frame - the frame in which this operand is used, used to resolve variables. The frame is also used to resolve current. Current is replaced with the agent performing the frame. The agent passed can be another agent then the current agent (in case of transfers from another agent).

strategy - the strategy to use to resolve this operand as a left hand side. NONE if an OA is not to be resolved, FACTS if facts are to be used to resolve an OA, BELIEFS if beliefs are to be used to resolve an OA

Returns:

LinkedList a list of operands that can be used in expressions located on the left hand side of a comparison.

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if the method was unable to get access to dynamic or static model elements

VMError - if an invalid element is encountered in the operand when considering this as part of a left hand side expression in a comparison.

See Also:

resolveAsRhs(gov.nasa.arc.brahms.vm.rt.VMActiveInstanceCtx, gov.nasa.arc.brahms.vm.rt.VMFrameCtx, int), IVMComparison.NONE, IVMComparison.FACTS, IVMComparison.BELIEFS

resolveObject

public java.util.LinkedList resolveObject(VMActiveInstanceCtx agent,
                                          VMFrameCtx frame)
                                   throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Resolves the object for this operand to one or more concepts provided this operand represents an object.

Parameters:

agent - the agent from which the belief set is to be used to resolve this operand

frame - the frame in which this operand is used, used to resolve variables. The frame is also used to resolve current. Current is replaced with the agent performing the frame. The agent passed can be another agent then the current agent (in case of transfers from another agent).

Returns:

LinkedList a list of resolved concepts.

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if the operand does not reference an object

VMError - if an invalid element is encountered in the operand when considering this as part of a left hand side expression in a comparison.

resolveAsRhs

public java.util.LinkedList resolveAsRhs(VMActiveInstanceCtx agent,
                                         VMFrameCtx frame,
                                         int strategy)
                                  throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Resolves this operand considering it to be part of an expression located on the right hand side in a comparison. As an operand in a right hand side expression in a comparison the operand can contain a nested expression or a value. The operand resolves itself by checking the object or if it is an expression resolving the expression. If it is an object and it is current, a variable, or a parameter they are resolved to concepts. This method returns one or more operands that can directly be used in expressions. If multiple concepts result from the resolution, then multiple operands are returned. If an attribute is specified, then all operands returned will be resolved to a value using the resolved object by looking up the value in the belief set of the agent and optionally by looking up the value in the fact set of the world.

Parameters:

agent - the agent from which the belief set is to be used to resolve this operand

frame - the frame in which this operand is used, used to resolve variables. The frame is also used to resolve current. Current is replaced with the agent performing the frame. The agent passed can be another agent then the current agent (in case of transfers from another agent).

strategy - the strategy to use to resolve this operand as a right hand side. FACTS if facts are to be used to resolve an OA, BELIEFS if beliefs are to be used to resolve an OA

Returns:

LinkedList a list of RhsOperandValue's that can be used in expressions located on the right hand side of a comparison.

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if the method was unable to get access to dynamic or static model elements

VMError - if an invalid element is encountered in the operand when considering this as part of a left hand side expression in a comparison.

See Also:

resolveAsLhs(gov.nasa.arc.brahms.vm.rt.VMActiveInstanceCtx, gov.nasa.arc.brahms.vm.rt.VMFrameCtx, int), IVMComparison.FACTS, IVMComparison.BELIEFS

resolveValue

public java.util.LinkedList resolveValue(VMActiveInstanceCtx agent,
                                         VMFrameCtx frame)
                                  throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Resolves the value of this operand, this method only resolves the object to the appropriate set of concepts or returns the value represented by this operand. This method does not yet resolve the values by matching with beliefs or facts taking into account the attribute defined for the operand.

Parameters:

agent - the agent from which the belief set is to be used to resolve this operand

frame - the frame in which this operand is used, used to resolve variables. The frame is also used to resolve current. Current is replaced with the agent performing the frame. The agent passed can be another agent then the current agent (in case of transfers from another agent).

Returns:

LinkedList a list of objectified values.

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if the method was unable to get access to dynamic or static model elements

VMError - if an invalid element is encountered in the operand when considering this as part of a left hand side expression in a comparison.

resolveCollectionIndex

public java.util.LinkedList resolveCollectionIndex(VMActiveInstanceCtx agent,
                                                   VMFrameCtx frame)
                                            throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Resolves the collection index of this operand, this method resolves the index value specified in this operand.

Parameters:

agent - the agent from which the belief set is to be used to resolve this operand

frame - the frame in which this operand is used, used to resolve variables.

Returns:

LinkedList a list of objectified values.

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if the method was unable to get access to dynamic or static model elements

buildRSN

public void buildRSN(gov.nasa.arc.brahms.vm.engine.rsn.ReasoningStateNetwork rsn,
                     gov.nasa.arc.brahms.vm.engine.rsn.IRSNFrameNode frame,
                     gov.nasa.arc.brahms.vm.engine.rsn.RSNActivityRefNode actref,
                     int modifier)
              throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Adds this operand to the reasoning state network to build up a reasoning state network that maintains a state of what statements matched with the operand.

Parameters:

rsn - the ReasoningStateNetwork to be built

frame - the RSNFrameNode for the frame in which this condition element is used.

actref - the optional RSNActivityRefNode for the activity reference referencing a composite activity in which the frame and the precondition are specified.

modifier - the modifier of the (pre)condition

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if an error occurs in building up the RSN with this expression

evaluate

public boolean evaluate(gov.nasa.arc.brahms.vm.engine.rsn.RSNFrameNode frame,
                        int modifier,
                        int relop,
                        gov.nasa.arc.brahms.vm.engine.rsn.RSNFrameNode.FrameEvaluationRecord evalRcd,
                        java.util.LinkedList values)
                 throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Evaluates the operand as part of a precondition determining whether or not the operand has a successfull match with a statement. If so the operand evaluates to true.

Parameters:

frame - the RSNFrameNode for the frame in which the operand's precondition is specified

modifier - the modifier of the (pre)condition

relop - relational operator used to find OA matches, -1 if relop can be ignored, otherwise one of Relation.EQ or Relation.NE

evalRcd - the record in which to store bindings for variables and statements matching preconditions

values - the list of values matching the operand

Returns:

true if the operand evaluates to true, false otherwise

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if an internal error occurs

assign

public void assign(java.util.List<java.lang.Object> values,
                   VMActiveInstanceCtx agent,
                   VMFrameCtx frame,
                   Type collectType)
            throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Assigns a list of values to the element resulting from evaluating the left-hand side expression. the boolean collect parameter is true, the list of values is assigned as a single collection value to the left-hand side element. If the collect parameter is false only the first value in the list is assigned.

Specified by:

assign in interface IVMAssignmentLhs

Parameters:

values - the list of values to be assigned

agent - the VMActiveInstanceCtx for the agent performing the assignment operation

frame - the VMFrameCtx for the frame that is being executed

collectType - the collection element type if the values should be assigned as a collection to the left-hand side, else null

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if an error occurs during the assignment

coerceValue

public java.lang.Object coerceValue(java.lang.Object value,
                                    Type brahmsType)
                             throws gov.nasa.arc.brahms.common.exceptions.BrahmsException

Attempts to coerce a value to a form that can be assigned to a variable of a given Brahms type. Returns null if unable to perform the coercion.

Parameters:

value - the value to be coerced

brahmsType - the Brahms type to which the value should be coerced

Returns:

Object the result of the coercion or null if the coercion fails

Throws:

gov.nasa.arc.brahms.common.exceptions.BrahmsException - if an error occurs during the attempted coercion

getConditionElementID

public final java.lang.String getConditionElementID(gov.nasa.arc.brahms.vm.engine.rsn.IRSNFrameNode frame)

Returns the condition element id for this operand for the specified frame node.

Parameters:

frame - the IRSNFrameNode for which the condition element is requested

Returns:

String the condition element if it exists, null if no condition element is specified.