ES4 work

Jeff Dyer jodyer at
Fri Feb 15 18:38:08 PST 2008


We have entered a new phase in the development of the ES4 standard. Since
September we have had a fixed set of proposals to consider individually and
as a whole. The final step is to translate those proposals into production
implementations and to document the language that results to become the next
ES standard.

What follows is a high level description of the process that we (Adobe and
Mozilla) feel should be followed to get from Proposals to a high quality,
finished specification.

We should discuss this at our ES4-WG phone call this Tuesday (Feb-19).
Advanced comments welcomed.


The basic workflow:

  Proposal -->
     Implementation -->
        Feature spec -->
           Feature review -->
              ES4-RI -->
                 ES4 spec -->

Proposal - see
These proposals are the pool of possible feature proposals. Only exceptional
circumstances will warrant a feature not covered by an accepted proposal to
be considered.

Implementation - interested implementers collaborate on the implementation
of a feature described by the proposals. This exercise should end with one
or more implementations of the feature to provide feedback on usability and
implementation complexity.

Feature spec - one of the participants from the implementation team writes
up a description of the feature based on that implementation. Feature specs
are complete and accurate descriptions of individual features to be added to
the language. They are supported by production implementation, test cases
and implementer commitment to release the feature.

Feature review - ES4-WG reviews the feature spec and implementation and when
satisfied accepts the spec to be included in the ES4 spec.

ES4-RI - once accepted, the RI is checked for compatibility with the
production implementation and readability. Although the RI is used as a kind
of prototype of the proposals, its primary purpose is aide in understanding
and exposition of the language. This step involves preparing parts of the RI
for inclusion in the spec.

ES4 spec - and finally, the ES4 draft is updated to include the accepted
feature and reviewed first by ES4-WG and then TC39.


The implementation teams will be ad hoc collaborations between two or more
implementers. Ideally, at least one of those implementers is an Ecma member
so that the feature has representation throughout the standardization


The ES4-WG meetings should focus on the review of feature specs and ES4 spec
drafts. Two weeks before each TC39 meeting a draft of the ES4 spec will be
distributed for review by the TC39 members.


In order to be approved at the December 2008 GA, a final draft of the ES4
spec must be ready for review at the Sep TC39 meeting. This is clearly an
aggressive schedule, but one that is achievable given that high quality
feature specs are produced by several feature teams in parallel.

We envision at least two teams working in parallel on AS3-like features and
JS1.7-like features.

Here is a very high-level schedule of deliverables to TC39

Mar - draft 1

   - ES3 spec based on the ES4-RI
   - Library spec

May - draft 2

   - Core language mostly spec-ed

Jul - draft 3

   - Spec complete

Sep - draft 4

   - Final review

Oct - final draft

   - Send to CC for approval

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