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package jdk.nashorn.internal.ir;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
IR representation for an IF statement.
/**
* IR representation for an IF statement.
*/
@Immutable
public final class IfNode extends Statement implements JoinPredecessor {
private static final long serialVersionUID = 1L;
Test expression. /** Test expression. */
private final Expression test;
Pass statements. /** Pass statements. */
private final Block pass;
Fail statements. /** Fail statements. */
private final Block fail;
Local variable conversions that need to be performed after test if it evaluates to false, and there's no else
branch.
/**
* Local variable conversions that need to be performed after test if it evaluates to false, and there's no else
* branch.
*/
private final LocalVariableConversion conversion;
Constructor
Params: - lineNumber – line number
- token – token
- finish – finish
- test – test
- pass – block to execute when test passes
- fail – block to execute when test fails or null
/**
* Constructor
*
* @param lineNumber line number
* @param token token
* @param finish finish
* @param test test
* @param pass block to execute when test passes
* @param fail block to execute when test fails or null
*/
public IfNode(final int lineNumber, final long token, final int finish, final Expression test, final Block pass, final Block fail) {
super(lineNumber, token, finish);
this.test = test;
this.pass = pass;
this.fail = fail;
this.conversion = null;
}
private IfNode(final IfNode ifNode, final Expression test, final Block pass, final Block fail, final LocalVariableConversion conversion) {
super(ifNode);
this.test = test;
this.pass = pass;
this.fail = fail;
this.conversion = conversion;
}
@Override
public boolean isTerminal() {
return pass.isTerminal() && fail != null && fail.isTerminal();
}
@Override
public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
if (visitor.enterIfNode(this)) {
return visitor.leaveIfNode(
setTest((Expression)test.accept(visitor)).
setPass((Block)pass.accept(visitor)).
setFail(fail == null ? null : (Block)fail.accept(visitor)));
}
return this;
}
@Override
public void toString(final StringBuilder sb, final boolean printTypes) {
sb.append("if (");
test.toString(sb, printTypes);
sb.append(')');
}
Get the else block of this IfNode
Returns: the else block, or null if none exists
/**
* Get the else block of this IfNode
* @return the else block, or null if none exists
*/
public Block getFail() {
return fail;
}
private IfNode setFail(final Block fail) {
if (this.fail == fail) {
return this;
}
return new IfNode(this, test, pass, fail, conversion);
}
Get the then block for this IfNode
Returns: the then block
/**
* Get the then block for this IfNode
* @return the then block
*/
public Block getPass() {
return pass;
}
private IfNode setPass(final Block pass) {
if (this.pass == pass) {
return this;
}
return new IfNode(this, test, pass, fail, conversion);
}
Get the test expression for this IfNode
Returns: the test expression
/**
* Get the test expression for this IfNode
* @return the test expression
*/
public Expression getTest() {
return test;
}
Reset the test expression for this IfNode
Params: - test – a new test expression
Returns: new or same IfNode
/**
* Reset the test expression for this IfNode
* @param test a new test expression
* @return new or same IfNode
*/
public IfNode setTest(final Expression test) {
if (this.test == test) {
return this;
}
return new IfNode(this, test, pass, fail, conversion);
}
@Override
public IfNode setLocalVariableConversion(final LexicalContext lc, final LocalVariableConversion conversion) {
if(this.conversion == conversion) {
return this;
}
return new IfNode(this, test, pass, fail, conversion);
}
@Override
public LocalVariableConversion getLocalVariableConversion() {
return conversion;
}
}