JSDT/JSDT-DOM-and-bindings

This page explains the ClosureCompiler AST, the JSDT core DOM AST and its Bindings to the Eclipse IDE, including

• History of JSDT parsing from 1.0 to 2.0
• Parsing with Closure Compiler and generation of its AST: the ParseTree
• Conversion of the AST from the CC ParseTree to the jsdt.core.dom.AST (aka DOM Model) .
• Binding of the DOM model, to provide outline, content assist, indexing, etc.

Other JSDT Architectural information is reported in the parent page JSDT/Architecture.

JSDT parsing from 1.0 to 2.0

Starting from Eclipse Oxygen, JSDT 2.0 uses Closure Compiler for parsing. After parsing, a converter transforms the CC's ParseTree into the jsdt.core.dom.AST. Then, bindings are used to consume the DOM model to provide content assist, code completion, etc.

In the past, we changed parser/compiler toolchain twice:

• JSDT 1.0, until Mars.2: supports ES3 using Rhino (Mozilla Foundation), a Java-based parser/compiler for JavaScript.
• JSDT 2.0, initial release: supports ES6 using Esprima (jQuery Foundation). As Esprima is written in JavaScript, this version of JSDT 2.0 needs to hook Nashorn, the Java8’s JS interpreter.
• JSDT 2.0, from Neon.2 release: supports ES6 using ClosureCompiler (Google), a java-based parsing infrastructure for JavaScript.

ClosureCompiler AST

The google/closure-compiler project, has a wiki with tutorials, FAQs and design documents, which explain how to use the Java API, and how to write compiler passes. Anyway, most of the documentation is in the code, and we suggest you take a look at the followings:

• Closure Compiler source on GitHub: https://github.com/google/closure-compiler
• Adding closure compiler for JSDT parsing: https://git.eclipse.org/r/#/c/92404/

DOM AST

The AST class The package org.eclipse.wst.jsdt.core.dom contains the class

This is the AST used in JSDT core. It contains all the information needed to create outline, for content assist etc..

Bindings

This part is about the bindings needed to show the model in the outline, to provide content assist, indexing etc.

Other Notes

See commit https://git.eclipse.org/r/#/c/57504/ (M.Istria) to see the new outline