Package ch.usi.si.seart.treesitter

Class OffsetTreeCursor

java.lang.Object

ch.usi.si.seart.treesitter.TreeCursor

ch.usi.si.seart.treesitter.OffsetTreeCursor

All Implemented Interfaces:

AutoCloseable, Cloneable

public class OffsetTreeCursor
extends TreeCursor

Specialization of TreeCursor that applies a positional offset to visited nodes. Retrieving nodes by either getCurrentNode() or getCurrentTreeCursorNode() applies the offset to a copy of the original node, meaning that the tree is not mutated during traversal.

So what exactly is the purpose of this cursor? Imagine a scenario in which we need to print out the node positions of a source code file that begins with n blank lines. Rather than modifying the original file, we can just use this cursor with a positional offset of new Position(-n, 0). Likewise, when printing node positions of an indented function, the n spaces of indentation can be negated with a positional offset of new Position(0, -n). Row and column offsets can be combined with various positive and negative arrangements.

Since:

1.2.0

Author:

Ozren Dabić

Constructor Summary

Constructors

Constructor	Description
OffsetTreeCursor(@NotNull Node node, @NotNull Point offset)

Method Summary

Modifier and Type	Method	Description
TreeCursor	clone()	Clone this cursor, creating a separate, independent instance.
void	close()	Delete the external resource, freeing all the memory that it used.
boolean	equals(Object obj)
String	getCurrentFieldName()	Get the field name of the Node that the cursor is currently pointing to.
Node	getCurrentNode()	Get the Node that the cursor is currently pointing to.
TreeCursorNode	getCurrentTreeCursorNode()	Get the TreeCursorNode representation of the Node that the cursor is currently pointing to.
boolean	gotoFirstChild()	Move the cursor to the first child of its current node.
boolean	gotoFirstChild(int offset)	Move the cursor to the first child of its current node that extends beyond the given byte offset.
boolean	gotoFirstChild(@NotNull Point point)	Move the cursor to the first child of its current node that extends beyond the given row-column offset.
boolean	gotoNextSibling()	Move the cursor to the next sibling of its current node.
boolean	gotoNode(@NotNull Node node)	Move the cursor to an arbitrary node.
boolean	gotoParent()	Move the cursor to the parent of its current node.
int	hashCode()
boolean	isNull()	Checks whether the memory address associated with this external resource is nullptr.
void	preorderTraversal(@NotNull Consumer<Node> callback)	Iteratively traverse over the parse tree, applying a callback to the nodes before they are visited.
String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

OffsetTreeCursor

public OffsetTreeCursor(@NotNull
                        @NotNull Node node,
                        @NotNull
                        @NotNull Point offset)

Method Detail

close

public void close()

Delete the external resource, freeing all the memory that it used.

Specified by:

close in interface AutoCloseable

getCurrentFieldName

public String getCurrentFieldName()

Description copied from class: TreeCursor

Get the field name of the Node that the cursor is currently pointing to.

Returns:

the field name of the tree cursor's current node, null if the current node doesn't have a field

gotoFirstChild

public boolean gotoFirstChild()

Description copied from class: TreeCursor

Move the cursor to the first child of its current node.

Returns:

true if the cursor successfully moved, and false if there were no children

gotoFirstChild

public boolean gotoFirstChild(int offset)

Description copied from class: TreeCursor

Move the cursor to the first child of its current node that extends beyond the given byte offset.

Parameters:

offset - the starting byte of the child

Returns:

true if the cursor successfully moved, and false if no such child was found

gotoFirstChild

public boolean gotoFirstChild(@NotNull
                              @NotNull Point point)

Description copied from class: TreeCursor

Move the cursor to the first child of its current node that extends beyond the given row-column offset.

Parameters:

point - the starting row-column position of the child

Returns:

true if the cursor successfully moved, and false if no such child was found

gotoNextSibling

public boolean gotoNextSibling()

Description copied from class: TreeCursor

Move the cursor to the next sibling of its current node.

Returns:

true if the cursor successfully moved, and false if there was no next sibling node

gotoParent

public boolean gotoParent()

Description copied from class: TreeCursor

Move the cursor to the parent of its current node.

Returns:

true if the cursor successfully moved, and false if there was no parent node (the cursor was already on the root node)

gotoNode

public boolean gotoNode(@NotNull
                        @NotNull Node node)

Description copied from class: TreeCursor

Move the cursor to an arbitrary node.

Overrides:

gotoNode in class TreeCursor

Parameters:

node - target node to move the cursor to.

Returns:

true if the cursor successfully moved, and false if it was already at the specified node

preorderTraversal

public void preorderTraversal(@NotNull
                              @NotNull Consumer<Node> callback)

Description copied from class: TreeCursor

Iteratively traverse over the parse tree, applying a callback to the nodes before they are visited.

Parameters:

callback - The callback consumer which will execute upon visiting a node

getCurrentNode

public Node getCurrentNode()

Description copied from class: TreeCursor

Get the Node that the cursor is currently pointing to.

Returns:

the tree cursor's current node

clone

public TreeCursor clone()

Description copied from class: TreeCursor

Clone this cursor, creating a separate, independent instance.

Returns:

a clone of this instance

toString

public String toString()

Overrides:

toString in class Object

getCurrentTreeCursorNode

public TreeCursorNode getCurrentTreeCursorNode()

Description copied from class: TreeCursor

Get the TreeCursorNode representation of the Node that the cursor is currently pointing to.

Returns:

the tree cursor's current node

isNull

public final boolean isNull()

Checks whether the memory address associated with this external resource is nullptr.

Returns:

true if the memory address is 0, otherwise false

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object