* InfixExpression:
* Expression InfixOperator Expression { InfixOperator Expression }
*
*
* @since 2.0
* @noinstantiate This class is not intended to be instantiated by clients.
*/
public class InfixExpression extends Expression {
/**
* Infix operators (typesafe enumeration).
*
* InfixOperator:
* * TIMES
* / DIVIDE
* % REMAINDER
* + PLUS
* - MINUS
* << LEFT_SHIFT
* >> RIGHT_SHIFT_SIGNED
* >>> RIGHT_SHIFT_UNSIGNED
* < LESS
* > GREATER
* <= LESS_EQUALS
* >= GREATER_EQUALS
* == EQUALS
* != NOT_EQUALS
* ^ XOR
* & AND
* | OR
* && CONDITIONAL_AND
* || CONDITIONAL_OR
*
*/
public static class Operator {
/**
* The token for the operator.
*/
private String token;
/**
* Creates a new infix operator with the given token.
* * Note: this constructor is private. The only instances * ever created are the ones for the standard operators. *
* * @param token the character sequence for the operator */ private Operator(String token) { this.token = token; } /** * Returns the character sequence for the operator. * * @return the character sequence for the operator */ public String toString() { return token; } /** Multiplication "*" operator. */ public static final Operator TIMES = new Operator("*");//$NON-NLS-1$ /** Division "/" operator. */ public static final Operator DIVIDE = new Operator("/");//$NON-NLS-1$ /** Remainder "%" operator. */ public static final Operator REMAINDER = new Operator("%");//$NON-NLS-1$ /** Addition (or string concatenation) "+" operator. */ public static final Operator PLUS = new Operator("+");//$NON-NLS-1$ /** Subtraction "-" operator. */ public static final Operator MINUS = new Operator("-");//$NON-NLS-1$ /** Left shift "<<" operator. */ public static final Operator LEFT_SHIFT = new Operator("<<");//$NON-NLS-1$ /** Signed right shift ">>" operator. */ public static final Operator RIGHT_SHIFT_SIGNED = new Operator(">>");//$NON-NLS-1$ /** Unsigned right shift ">>>" operator. */ public static final Operator RIGHT_SHIFT_UNSIGNED = new Operator(">>>");//$NON-NLS-1$ /** Less than "<" operator. */ public static final Operator LESS = new Operator("<");//$NON-NLS-1$ /** Greater than ">" operator. */ public static final Operator GREATER = new Operator(">");//$NON-NLS-1$ /** Less than or equals "<=" operator. */ public static final Operator LESS_EQUALS = new Operator("<=");//$NON-NLS-1$ /** Greater than or equals ">=;" operator. */ public static final Operator GREATER_EQUALS = new Operator(">=");//$NON-NLS-1$ /** Equals "==" operator. */ public static final Operator EQUALS = new Operator("==");//$NON-NLS-1$ /** Not equals "!=" operator. */ public static final Operator NOT_EQUALS = new Operator("!=");//$NON-NLS-1$ /** Exclusive OR "^" operator. */ public static final Operator XOR = new Operator("^");//$NON-NLS-1$ /** Inclusive OR "|" operator. */ public static final Operator OR = new Operator("|");//$NON-NLS-1$ /** AND "&" operator. */ public static final Operator AND = new Operator("&");//$NON-NLS-1$ /** Conditional OR "||" operator. */ public static final Operator CONDITIONAL_OR = new Operator("||");//$NON-NLS-1$ /** Conditional AND "&&" operator. */ public static final Operator CONDITIONAL_AND = new Operator("&&");//$NON-NLS-1$ /** * Map from token to operator (key type:String;
* value type: Operator).
*/
private static final Map CODES;
static {
CODES = new HashMap(20);
Operator[] ops = {
TIMES,
DIVIDE,
REMAINDER,
PLUS,
MINUS,
LEFT_SHIFT,
RIGHT_SHIFT_SIGNED,
RIGHT_SHIFT_UNSIGNED,
LESS,
GREATER,
LESS_EQUALS,
GREATER_EQUALS,
EQUALS,
NOT_EQUALS,
XOR,
OR,
AND,
CONDITIONAL_OR,
CONDITIONAL_AND,
};
for (int i = 0; i < ops.length; i++) {
CODES.put(ops[i].toString(), ops[i]);
}
}
/**
* Returns the infix operator corresponding to the given string,
* or null if none.
*
* toOperator is the converse of toString:
* that is, Operator.toOperator(op.toString()) == op for
* all operators op.
*
null if none
*/
public static Operator toOperator(String token) {
return (Operator) CODES.get(token);
}
}
/**
* The "leftOperand" structural property of this node type.
* @since 3.0
*/
public static final ChildPropertyDescriptor LEFT_OPERAND_PROPERTY =
new ChildPropertyDescriptor(InfixExpression.class, "leftOperand", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
/**
* The "operator" structural property of this node type.
* @since 3.0
*/
public static final SimplePropertyDescriptor OPERATOR_PROPERTY =
new SimplePropertyDescriptor(InfixExpression.class, "operator", InfixExpression.Operator.class, MANDATORY); //$NON-NLS-1$
/**
* The "rightOperand" structural property of this node type.
* @since 3.0
*/
public static final ChildPropertyDescriptor RIGHT_OPERAND_PROPERTY =
new ChildPropertyDescriptor(InfixExpression.class, "rightOperand", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
/**
* The "extendedOperands" structural property of this node type.
* @since 3.0
*/
public static final ChildListPropertyDescriptor EXTENDED_OPERANDS_PROPERTY =
new ChildListPropertyDescriptor(InfixExpression.class, "extendedOperands", Expression.class, CYCLE_RISK); //$NON-NLS-1$
/**
* A list of property descriptors (element type:
* {@link StructuralPropertyDescriptor}),
* or null if uninitialized.
*/
private static final List PROPERTY_DESCRIPTORS;
static {
List properyList = new ArrayList(5);
createPropertyList(InfixExpression.class, properyList);
addProperty(LEFT_OPERAND_PROPERTY, properyList);
addProperty(OPERATOR_PROPERTY, properyList);
addProperty(RIGHT_OPERAND_PROPERTY, properyList);
addProperty(EXTENDED_OPERANDS_PROPERTY, properyList);
PROPERTY_DESCRIPTORS = reapPropertyList(properyList);
}
/**
* Returns a list of structural property descriptors for this node type.
* Clients must not modify the result.
*
* @param apiLevel the API level; one of the
* AST.JLS* constants
* @return a list of property descriptors (element type:
* {@link StructuralPropertyDescriptor})
* @since 3.0
*/
public static List propertyDescriptors(int apiLevel) {
return PROPERTY_DESCRIPTORS;
}
/**
* The infix operator; defaults to InfixExpression.Operator.PLUS.
*/
private InfixExpression.Operator operator = InfixExpression.Operator.PLUS;
/**
* The left operand; lazily initialized; defaults to an unspecified,
* but legal, simple name.
*/
private Expression leftOperand = null;
/**
* The right operand; lazily initialized; defaults to an unspecified,
* but legal, simple name.
*/
private Expression rightOperand = null;
/**
* The list of extended operand expressions (element type:
* Expression). Lazily initialized; defaults to an empty list.
*/
private ASTNode.NodeList extendedOperands = null;
/**
* Creates a new AST node for an infix expression owned by the given
* AST. By default, the node has unspecified (but legal) operator,
* left and right operands, and an empty list of additional operands.
*
* @param ast the AST that is to own this node
*/
InfixExpression(AST ast) {
super(ast);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final List internalStructuralPropertiesForType(int apiLevel) {
return propertyDescriptors(apiLevel);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final Object internalGetSetObjectProperty(SimplePropertyDescriptor property, boolean get, Object value) {
if (property == OPERATOR_PROPERTY) {
if (get) {
return getOperator();
} else {
setOperator((Operator) value);
return null;
}
}
// allow default implementation to flag the error
return super.internalGetSetObjectProperty(property, get, value);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
if (property == LEFT_OPERAND_PROPERTY) {
if (get) {
return getLeftOperand();
} else {
setLeftOperand((Expression) child);
return null;
}
}
if (property == RIGHT_OPERAND_PROPERTY) {
if (get) {
return getRightOperand();
} else {
setRightOperand((Expression) child);
return null;
}
}
// allow default implementation to flag the error
return super.internalGetSetChildProperty(property, get, child);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final List internalGetChildListProperty(ChildListPropertyDescriptor property) {
if (property == EXTENDED_OPERANDS_PROPERTY) {
return extendedOperands();
}
// allow default implementation to flag the error
return super.internalGetChildListProperty(property);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final int getNodeType0() {
return INFIX_EXPRESSION;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
ASTNode clone0(AST target) {
InfixExpression result = new InfixExpression(target);
result.setSourceRange(this.getStartPosition(), this.getLength());
result.setOperator(getOperator());
result.setLeftOperand((Expression) getLeftOperand().clone(target));
result.setRightOperand((Expression) getRightOperand().clone(target));
if (this.extendedOperands != null) {
// be careful not to trigger lazy creation of list
result.extendedOperands().addAll(
ASTNode.copySubtrees(target, this.extendedOperands()));
}
return result;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final boolean subtreeMatch0(ASTMatcher matcher, Object other) {
// dispatch to correct overloaded match method
return matcher.match(this, other);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
void accept0(ASTVisitor visitor) {
boolean visitChildren = visitor.visit(this);
if (visitChildren) {
// visit children in normal left to right reading order
acceptChild(visitor, getLeftOperand());
acceptChild(visitor, getRightOperand());
if (this.extendedOperands != null) {
// be careful not to trigger lazy creation of list
acceptChildren(visitor, this.extendedOperands);
}
}
visitor.endVisit(this);
}
/**
* Returns the operator of this infix expression.
*
* @return the infix operator
*/
public InfixExpression.Operator getOperator() {
return this.operator;
}
/**
* Sets the operator of this infix expression.
*
* @param operator the infix operator
* @exception IllegalArgumentException if the argument is incorrect
*/
public void setOperator(InfixExpression.Operator operator) {
if (operator == null) {
throw new IllegalArgumentException();
}
preValueChange(OPERATOR_PROPERTY);
this.operator = operator;
postValueChange(OPERATOR_PROPERTY);
}
/**
* Returns the left operand of this infix expression.
*
* @return the left operand node
*/
public Expression getLeftOperand() {
if (this.leftOperand == null) {
// lazy init must be thread-safe for readers
synchronized (this) {
if (this.leftOperand == null) {
preLazyInit();
this.leftOperand= new SimpleName(this.ast);
postLazyInit(this.leftOperand, LEFT_OPERAND_PROPERTY);
}
}
}
return this.leftOperand;
}
/**
* Sets the left operand of this infix expression.
*
* @param expression the left operand node
* @exception IllegalArgumentException if:
* true if there are one or more extended operands,
* and false if there are no extended operands
*/
public boolean hasExtendedOperands() {
return
(this.extendedOperands != null) && this.extendedOperands.size() > 0;
}
/**
* Returns the live list of extended operands.
*
* The extended operands is the preferred way of representing deeply nested
* expressions of the form L op R op R2 op R3... where
* the same operator appears between all the operands (the most
* common case being lengthy string concatenation expressions). Using
* the extended operands keeps the trees from getting too deep; this
* decreases the risk is running out of thread stack space at runtime
* when traversing such trees.
* ((a + b) + c) + d would be translated to:
* leftOperand: a
* rightOperand: b
* extendedOperands: {c, d}
* operator: +
*
Expression)
*/
public List extendedOperands() {
if (this.extendedOperands == null) {
// lazily initialize
this.extendedOperands = new ASTNode.NodeList(EXTENDED_OPERANDS_PROPERTY);
}
return this.extendedOperands;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
int memSize() {
// treat Operator as free
return BASE_NODE_SIZE + 4 * 4;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
int treeSize() {
return
memSize()
+ (this.leftOperand == null ? 0 : getLeftOperand().treeSize())
+ (this.rightOperand == null ? 0 : getRightOperand().treeSize())
+ (this.extendedOperands == null ? 0 : extendedOperands.listSize());
}
}