org.problets.domain.model.expression.node.operator.assignment
Class PrefixAssignment

java.lang.Object
  org.problets.domain.model.DomainModel
      org.problets.domain.model.expression.node.NodeModel
          org.problets.domain.model.expression.node.operator.Operator
              org.problets.domain.model.expression.node.operator.assignment.Assignment
                  org.problets.domain.model.expression.node.operator.assignment.PrefixAssignment

All Implemented Interfaces:

java.lang.Cloneable, Assignable

Direct Known Subclasses:

PrefixDecrement, PrefixIncrement

public abstract class PrefixAssignment
extends Assignment
implements Assignable

Serves as the base class for prefix increment and decrement operators

Since:

3 / 26 / 2008

Author:

Amruth Kumar

Field Summary

Fields inherited from class org.problets.domain.model.expression.node.operator.assignment.Assignment

TOTAL_OPERATORS

Fields inherited from class org.problets.domain.model.expression.node.operator.Operator

INCORRECT_OPERAND_COUNT

Fields inherited from class org.problets.domain.model.DomainModel

BOOLEAN, BREAKPOINT, CHARACTER, DOUBLE_PRECISION_REAL, ERROR_TYPE, EVAL_STATUS, expACTION, expASSIGNMENT, expAUTO_DEALLOCATION, expCALL, expCONDITION, expDECLARATION, expDEREFERENCING, expDYNAMIC_ALLOCATION, expDYNAMIC_ALLOCATION_INITIALIZATION, expDYNAMIC_DEALLOCATION, expELSE_CLAUSE, expERROR, expEXECUTION, expIF_CLAUSE, expINITIALIZATION, expINPUT, expPARAMETER_PASSING, expPRINT, expQUESTIONABLE, expREFERENCING, expRETURN, expRUNTIME_ERROR, expSEMANTIC_ERROR, expSYNTAX_ERROR, expUPDATE, IDENTITY, MAX_OBJECT_IDENTITY, MIN_OBJECT_IDENTITY, QUADRUPLE_PRECISION_REAL, RUNTIME_ERROR, SEMANTIC_ERROR, SIGNED_INTEGER, SIGNED_LONG, SIGNED_SHORT, SINGLE_PRECISION_REAL, SYNTAX_ERROR, UNDEFINED_TYPE, UNSIGNED_INTEGER, UNSIGNED_LONG, UNSIGNED_SHORT, WARNING

Constructor Summary

PrefixAssignment(java.lang.String inSymbol, int inPrecedence, java.lang.String inAssociativity, int inArity)

Method Summary

boolean	canAssign() Returns whether this node is assignable - since prefix operator returns lvalue in C++, it is true for C++, but false for Java.
Value	evaluate() Method to detect any errors before subclasses evaluate expressions Not to be used by client.
void	explain(java.util.Vector explanation, java.util.Vector errors) Textually explains the evaluation of the tree - as opposed to graphical explanation by the view
AbstractVarModel	getClone() If right is a VarOperand, get its varClone Else, call getClone recursively on the right operand, In either case, add getIncrement() to the value of the clone, and return it.
AbstractVarModel	getVarReference() Returns a reference to the variable that is this operand.
static void	main(java.lang.String[] args)
void	setVarValue(Value inValue) Sets the value of the variable which is this operand.

Methods inherited from class org.problets.domain.model.expression.node.operator.assignment.Assignment

addSideEffects, clone, getSideEffects, getStudentCopy

Methods inherited from class org.problets.domain.model.expression.node.operator.Operator

coerceToReal, contentEquals, contentEquals, getArity, getAssociativity, getLocalLearningObjectives, getOperatorType, getPrecedence, getQualifiedLearningObject, getSymbol, grade, locateOperator, recursiveContentEquals, recursiveSetValue

Methods inherited from class org.problets.domain.model.expression.node.NodeModel

classifyNodes, getContent, getLeftChild, getNonRecursiveContent, getOrder, getPosition, getRecursiveContent, getRightChild, getValue, insertInOrder, setLeftChild, setOrder, setPosition, setRightChild, setValue, shortCircuit, skip, subExpToString, toString, valueEquals

Methods inherited from class org.problets.domain.model.DomainModel

getId, getIdName, grade

Methods inherited from class java.lang.Object

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

Constructor Detail

PrefixAssignment

public PrefixAssignment(java.lang.String inSymbol,
                        int inPrecedence,
                        java.lang.String inAssociativity,
                        int inArity)

Method Detail

canAssign

public boolean canAssign()

Returns whether this node is assignable - since prefix operator returns lvalue in C++, it is true for C++, but false for Java.

Specified by:

canAssign in interface Assignable

getVarReference

public AbstractVarModel getVarReference()

Returns a reference to the variable that is this operand. Do not directly reference the variable returned by this function as part of any expression evaluation - use getValue() instead. Feel free to set the value of the variable returned by this function.

Specified by:

getVarReference in interface Assignable

setVarValue

public void setVarValue(Value inValue)

Sets the value of the variable which is this operand. Use this always to set the value of the variable

Specified by:

setVarValue in interface Assignable

getClone

public AbstractVarModel getClone()

If right is a VarOperand, get its varClone Else, call getClone recursively on the right operand, In either case, add getIncrement() to the value of the clone, and return it.

Specified by:

getClone in interface Assignable

evaluate

public Value evaluate()

Description copied from class: Assignment

Method to detect any errors before subclasses evaluate expressions Not to be used by client. Checks if LHS is a variable, and RHS evaluates correctly

Overrides:

evaluate in class Assignment

explain

public void explain(java.util.Vector explanation,
                    java.util.Vector errors)

Textually explains the evaluation of the tree - as opposed to graphical explanation by the view

Overrides:

explain in class Operator

main

public static void main(java.lang.String[] args)