org.apache.sling.scripting.sightly.compiler.util

Class VariableTracker<T>

java.lang.Object

org.apache.sling.scripting.sightly.compiler.util.VariableTracker<T>

public final class VariableTracker<T>
extends Object

Tracks information related to HTL variables, at different levels of the compiler.

Constructor Summary

Constructors

Constructor and Description
VariableTracker()

Method Summary

Modifier and Type	Method and Description
T	get(String name) Get the data associated with the given variable.
List<T>	getAll(String name) Get an immutable view of all the data items associated with the specified variable.
int	getOccurrenceCount(String name) Get how many times a variable was declared in the current scope.
boolean	isDeclared(String name) Checks if the variable identified by name is tracked by this tracker or not.
boolean	isEmpty() Checks if the declaration stack is empty.
boolean	isInScope(String name) Check whether a variable was declared and is visible in the current scope.
Map.Entry<String,T>	peek() Peeks at the top of the declaration stack.
String	popVariable() Pops a variable from this tracker.
void	pushVariable(String name, T data) Pushes a variable to this tracker.

Methods inherited from class java.lang.Object

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

Constructor Detail

VariableTracker

public VariableTracker()

Method Detail

isDeclared

public boolean isDeclared(String name)

Checks if the variable identified by name is tracked by this tracker or not.

Parameters:

name - the name of the variable

Returns:

true if the variable is declared, false otherwise

pushVariable

public void pushVariable(String name,
                         T data)

Pushes a variable to this tracker. Call this method whenever a variable is declared.

Parameters:

name - the name of the variable

data - the data associated with the variable

popVariable

public String popVariable()

Pops a variable from this tracker. Call this method whenever a variable goes out of scope.

Returns:

the name of the popped variable

Throws:

NoSuchElementException - if there are no declared variables in the scope

peek

public Map.Entry<String,T> peek()

Peeks at the top of the declaration stack.

Returns:

the most recently declared variable and its associated data

Throws:

NoSuchElementException - if there are no variables in scope

isEmpty

public boolean isEmpty()

Checks if the declaration stack is empty.

Returns:

true if the stack is empty, false otherwise

get

public T get(String name)

Get the data associated with the given variable.

Parameters:

name - the name of the variable

Returns:

the associated data or null if that variable is not in scope

isInScope

public boolean isInScope(String name)

Check whether a variable was declared and is visible in the current scope.

Parameters:

name - the name of the variable

Returns:

true if the variable is visible in the current scope, false otherwise

getAll

public List<T> getAll(String name)

Get an immutable view of all the data items associated with the specified variable.

Parameters:

name - the name of the variable

Returns:

a list of all the data associated with this variable name. If the variable is not declared in the current scope then that list will be empty. Otherwise it will contain all the data associated for the current scope starting with the data associated at the topmost scope and ending with the most recently associated data

getOccurrenceCount

public int getOccurrenceCount(String name)

Get how many times a variable was declared in the current scope.

Parameters:

name - the name of the variable

Returns:

the number of declarations for a variable in the current scope