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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.

See also: 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:


The class AST (in package org.eclipse.wst.jsdt.core.dom), is the AST used in JSDT core. It contains all the information needed to create outline, content assist etc..


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


  • to create outline, look at this class/references
  • to provide content assist, look at these class/references:
  • to understand how indexing works, look at these references.

Other Notes

See commit (M.Istria) to see the new outline

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