Package org.codehaus.groovy.transform.tailrec

Class VariableExpressionReplacer

java.lang.Object

org.codehaus.groovy.ast.CodeVisitorSupport

org.codehaus.groovy.transform.tailrec.VariableExpressionReplacer

All Implemented Interfaces:

GroovyCodeVisitor

public class VariableExpressionReplacer
extends CodeVisitorSupport

Tool for replacing VariableExpression instances in an AST by other VariableExpression instances. Regardless of a real change taking place in nested expressions, all considered expression (trees) will be replaced. This could be optimized to accelerate compilation.

Within @TailRecursive it is used - to swap the access of method args with the access to iteration variables - to swap the access of iteration variables with the access of temp vars

Constructor Summary

Constructors

Constructor	Description
VariableExpressionReplacer(Closure<Boolean> when, Closure<VariableExpression> replaceWith)	Creates a replacer with the supplied predicate and replacement strategy.

Method Summary

Modifier and Type	Method	Description
Closure<VariableExpression>	getReplaceWith()	Returns the closure that creates replacement variable expressions.
Closure<Boolean>	getWhen()	Returns the predicate that decides whether a variable expression should be replaced.
void	replaceIn(ASTNode root)	Replaces matching variable expressions within the supplied AST subtree.
void	setReplaceWith(Closure<VariableExpression> replaceWith)	Sets the closure that creates replacement variable expressions.
void	setWhen(Closure<Boolean> when)	Sets the predicate that decides whether a variable expression should be replaced.
void	visitAssertStatement(AssertStatement statement)	Visits an AssertStatement, traversing the assertion condition and optional message expression.
void	visitBinaryExpression(BinaryExpression expression)	It's the only Expression type in which replacing is considered.
void	visitCaseStatement(CaseStatement statement)	Visits a CaseStatement, traversing the case expression and code block.
void	visitDoWhileLoop(DoWhileStatement loop)	Visits a DoWhileStatement, traversing the loop body before the boolean condition.
void	visitExpressionStatement(ExpressionStatement statement)	Visits an ExpressionStatement, traversing its contained expression.
void	visitForLoop(ForStatement forLoop)	Visits a ForStatement, traversing the collection expression and loop body.
void	visitIfElse(IfStatement ifElse)	Visits an IfStatement, traversing the condition, if-block, and optional else-block.
void	visitReturnStatement(ReturnStatement statement)	Visits a ReturnStatement, traversing its return expression.
void	visitSwitch(SwitchStatement statement)	Visits a SwitchStatement, traversing the switch expression, case statements, and default statement.
void	visitSynchronizedStatement(SynchronizedStatement statement)	Visits a SynchronizedStatement, traversing the synchronization expression and code block.
void	visitThrowStatement(ThrowStatement statement)	Visits a ThrowStatement, traversing the exception expression.
void	visitWhileLoop(WhileStatement loop)	Visits a WhileStatement, traversing the boolean condition and loop body.

Methods inherited from class org.codehaus.groovy.ast.CodeVisitorSupport

afterSwitchCaseStatementsVisited, afterSwitchConditionExpressionVisited, visitArgumentlistExpression, visitArrayExpression, visitAttributeExpression, visitBitwiseNegationExpression, visitBlockStatement, visitBooleanExpression, visitBreakStatement, visitBytecodeExpression, visitCastExpression, visitCatchStatement, visitClassExpression, visitClosureExpression, visitClosureListExpression, visitConstantExpression, visitConstructorCallExpression, visitContinueStatement, visitDeclarationExpression, visitEmptyStatement, visitFieldExpression, visitGStringExpression, visitLambdaExpression, visitListExpression, visitMapEntryExpression, visitMapExpression, visitMethodCallExpression, visitMethodPointerExpression, visitMethodReferenceExpression, visitNotExpression, visitPostfixExpression, visitPrefixExpression, visitPropertyExpression, visitRangeExpression, visitShortTernaryExpression, visitSpreadExpression, visitSpreadMapExpression, visitStaticMethodCallExpression, visitTernaryExpression, visitTryCatchFinally, visitTupleExpression, visitUnaryMinusExpression, visitUnaryPlusExpression, visitVariableExpression

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.codehaus.groovy.ast.GroovyCodeVisitor

visit, visit, visitEmptyExpression, visitListOfExpressions

Constructor Details

VariableExpressionReplacer

public VariableExpressionReplacer(Closure<Boolean> when,
 Closure<VariableExpression> replaceWith)

Creates a replacer with the supplied predicate and replacement strategy.

Parameters:

when - decides whether a variable expression should be replaced

replaceWith - creates the replacement variable expression

Method Details

visitReturnStatement

public void visitReturnStatement(ReturnStatement statement)

Visits a ReturnStatement, traversing its return expression.

Specified by:

visitReturnStatement in interface GroovyCodeVisitor

Overrides:

visitReturnStatement in class CodeVisitorSupport

Parameters:

statement - the return statement

visitIfElse

public void visitIfElse(IfStatement ifElse)

Visits an IfStatement, traversing the condition, if-block, and optional else-block.

Specified by:

visitIfElse in interface GroovyCodeVisitor

Overrides:

visitIfElse in class CodeVisitorSupport

Parameters:

ifElse - the if-else statement

visitForLoop

public void visitForLoop(ForStatement forLoop)

Visits a ForStatement, traversing the collection expression and loop body.

Specified by:

visitForLoop in interface GroovyCodeVisitor

Overrides:

visitForLoop in class CodeVisitorSupport

Parameters:

forLoop - the for loop statement

visitBinaryExpression

public void visitBinaryExpression(BinaryExpression expression)

It's the only Expression type in which replacing is considered. That's an abuse of the class, but I couldn't think of a better way.

Specified by:

visitBinaryExpression in interface GroovyCodeVisitor

Overrides:

visitBinaryExpression in class CodeVisitorSupport

Parameters:

expression - the binary expression

visitWhileLoop

public void visitWhileLoop(WhileStatement loop)

Visits a WhileStatement, traversing the boolean condition and loop body.

Specified by:

visitWhileLoop in interface GroovyCodeVisitor

Overrides:

visitWhileLoop in class CodeVisitorSupport

Parameters:

loop - the while loop statement

visitDoWhileLoop

public void visitDoWhileLoop(DoWhileStatement loop)

Visits a DoWhileStatement, traversing the loop body before the boolean condition.

Specified by:

visitDoWhileLoop in interface GroovyCodeVisitor

Overrides:

visitDoWhileLoop in class CodeVisitorSupport

Parameters:

loop - the do-while loop statement

visitSwitch

public void visitSwitch(SwitchStatement statement)

Visits a SwitchStatement, traversing the switch expression, case statements, and default statement.

Specified by:

visitSwitch in interface GroovyCodeVisitor

Overrides:

visitSwitch in class CodeVisitorSupport

Parameters:

statement - the switch statement

visitCaseStatement

public void visitCaseStatement(CaseStatement statement)

Visits a CaseStatement, traversing the case expression and code block.

Specified by:

visitCaseStatement in interface GroovyCodeVisitor

Overrides:

visitCaseStatement in class CodeVisitorSupport

Parameters:

statement - the case statement

visitExpressionStatement

public void visitExpressionStatement(ExpressionStatement statement)

Visits an ExpressionStatement, traversing its contained expression.

Specified by:

visitExpressionStatement in interface GroovyCodeVisitor

Overrides:

visitExpressionStatement in class CodeVisitorSupport

Parameters:

statement - the expression statement

visitThrowStatement

public void visitThrowStatement(ThrowStatement statement)

Visits a ThrowStatement, traversing the exception expression.

Specified by:

visitThrowStatement in interface GroovyCodeVisitor

Overrides:

visitThrowStatement in class CodeVisitorSupport

Parameters:

statement - the throw statement

visitAssertStatement

public void visitAssertStatement(AssertStatement statement)

Visits an AssertStatement, traversing the assertion condition and optional message expression.

Specified by:

visitAssertStatement in interface GroovyCodeVisitor

Overrides:

visitAssertStatement in class CodeVisitorSupport

Parameters:

statement - the assert statement

visitSynchronizedStatement

public void visitSynchronizedStatement(SynchronizedStatement statement)

Visits a SynchronizedStatement, traversing the synchronization expression and code block.

Specified by:

visitSynchronizedStatement in interface GroovyCodeVisitor

Overrides:

visitSynchronizedStatement in class CodeVisitorSupport

Parameters:

statement - the synchronized statement

replaceIn

public void replaceIn(ASTNode root)

Replaces matching variable expressions within the supplied AST subtree.

Parameters:

root - the AST subtree to mutate

getWhen

public Closure<Boolean> getWhen()

Returns the predicate that decides whether a variable expression should be replaced.

Returns:

the replacement predicate

setWhen

public void setWhen(Closure<Boolean> when)

Sets the predicate that decides whether a variable expression should be replaced.

Parameters:

when - the replacement predicate

getReplaceWith

public Closure<VariableExpression> getReplaceWith()

Returns the closure that creates replacement variable expressions.

Returns:

the replacement closure

setReplaceWith

public void setReplaceWith(Closure<VariableExpression> replaceWith)

Sets the closure that creates replacement variable expressions.

Parameters:

replaceWith - the replacement closure