Package com.google.javascript.jscomp

Class Es6SplitVariableDeclarations

java.lang.Object

com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

com.google.javascript.jscomp.Es6SplitVariableDeclarations

All Implemented Interfaces:

CompilerPass, HotSwapCompilerPass, NodeTraversal.Callback

public final class Es6SplitVariableDeclarations
extends NodeTraversal.AbstractPostOrderCallback
implements HotSwapCompilerPass

Splits variable declarations that declare multiple variables into separate declarations, if at least one of the declarations is a destructuring declaration. For example

   var [a, b] = foo(), c = bar();}
 

becomes

   var [a, b] = foo();
   var c = bar();
 

This runs before the main ES6 transpilation step, to simplify the transpilation of destructuring syntax.

Constructor Summary

Constructors

Constructor	Description
Es6SplitVariableDeclarations(AbstractCompiler compiler)

Method Summary

Modifier and Type	Method	Description
void	hotSwapScript(Node scriptRoot, Node originalRoot)	Process the JS with root node root.
void	process(Node externs, Node root)	Process the JS with root node root.
void	splitDeclaration(NodeTraversal t, Node n, Node parent)
void	visit(NodeTraversal t, Node n, Node parent)	Visits a node in postorder (after its children).

Methods inherited from class com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback

shouldTraverse

Methods inherited from class java.lang.Object

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

Constructor Detail

Es6SplitVariableDeclarations

public Es6SplitVariableDeclarations(AbstractCompiler compiler)

Method Detail

process

public void process(Node externs,
                    Node root)

Description copied from interface: CompilerPass

Process the JS with root node root. Can modify the contents of each Node tree

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

root - Top of JS tree

hotSwapScript

public void hotSwapScript(Node scriptRoot,
                          Node originalRoot)

Description copied from interface: HotSwapCompilerPass

Process the JS with root node root. This is supposed to be significantly faster compared to corresponding full-compiler passes.

Specified by:

hotSwapScript in interface HotSwapCompilerPass

Parameters:

scriptRoot - Root node corresponding to the file that is modified, should be of type Token.SCRIPT.

originalRoot - Root node corresponding to the original version of the file that is modified. Should be of type token.SCRIPT.

visit

public void visit(NodeTraversal t,
                  Node n,
                  Node parent)

Description copied from interface: NodeTraversal.Callback

Visits a node in postorder (after its children). A node is visited in postorder iff NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node) returned true for its parent. In particular, the root node is never visited in postorder.

Siblings are always visited left-to-right.

Implementations can have side-effects (e.g. modify the parse tree). Removing the current node is legal, but removing or reordering nodes above the current node may cause nodes to be visited twice or not at all.

Specified by:

visit in interface NodeTraversal.Callback

Parameters:

t - The current traversal.

n - The current node.

parent - The parent of the current node.

splitDeclaration

public void splitDeclaration(NodeTraversal t,
                             Node n,
                             Node parent)