com.google.javascript.jscomp

Class Es6ToEs3Converter

java.lang.Object

com.google.javascript.jscomp.Es6ToEs3Converter

All Implemented Interfaces:

CompilerPass, HotSwapCompilerPass, NodeTraversal.Callback

public final class Es6ToEs3Converter
extends Object
implements NodeTraversal.Callback, HotSwapCompilerPass

Converts ES6 code to valid ES5 code. This class does most of the transpilation, and https://github.com/google/closure-compiler/wiki/ECMAScript6 lists which ES6 features are supported. Other classes that start with "Es6" do other parts of the transpilation.

In most cases, the output is valid as ES3 (hence the class name) but in some cases, if the output language is set to ES5, we rely on ES5 features such as getters, setters, and Object.defineProperties.

Author:

[email protected] (Tyler Breisacher)

Constructor Summary

Constructors

Constructor and Description
Es6ToEs3Converter(AbstractCompiler compiler)

Method Summary

Modifier and Type	Method and 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.
boolean	shouldTraverse(NodeTraversal t, Node n, Node parent) Some nodes must be visited pre-order in order to rewrite the references to this correctly.
void	visit(NodeTraversal t, Node n, Node parent) Visits a node in postorder (after its children have been visited).

Methods inherited from class java.lang.Object

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

Constructor Detail

Es6ToEs3Converter

public Es6ToEs3Converter(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.

shouldTraverse

public boolean shouldTraverse(NodeTraversal t,
                              Node n,
                              Node parent)

Some nodes must be visited pre-order in order to rewrite the references to this correctly. Everything else is translated post-order in visit(com.google.javascript.jscomp.NodeTraversal, com.google.javascript.rhino.Node, com.google.javascript.rhino.Node).

Specified by:

shouldTraverse in interface NodeTraversal.Callback

Returns:

whether the children of this node should be visited

visit

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

Description copied from interface: NodeTraversal.Callback

Visits a node in postorder (after its children have been visited). A node is visited only if all its parents should be traversed (NodeTraversal.Callback.shouldTraverse(NodeTraversal, Node, Node)).

Implementations can have side effects (e.g. modifying the parse tree).

Specified by:

visit in interface NodeTraversal.Callback