Set LibLouis version to 2.7.0 or 3.0.0 once emphasis overhaul and other work are implemented

[josephsl]

Hi,

The work done by Mike, Davy and others on emphasis unification and other work seems promising. Since we're dealing with new opcodes and other work, let's bump LibLouis version to 2.7.0 or 3.0.0 (I'd vote for the latter).

Benefits and reasons:

• Opcode change is a major compatibility change, not only for LibLuis translator but also for users, table maintainers and developers using LibLouis such as screen reader vendors.
• By telling people that we'll be using Liblouis 3.x.y version number, people will know that there are major changes to be aware of, especially for current and new table maintainers and developers. Even using 2.7.0 may mean something for users, as it'll mean some significant change from 2.6.x days.

Disadvantages and costs:

• Some people would expect us to use 2.6.x scheme for a while given that not much has changed (some people may think this way if they don't know internals of LibLouis and think LibLouis is just a braille translation system).
• Learning curve and perception: Some may say using 3.x.y version number might indicate different table layouts and so on (a perception issue), thus these people may elect to stay with 2.6.x or 2.7.0 (or 2.x.y version number).

However, given the amount of work that's going under the hood in LibLouis to support UEB standard properly and since the new opcodes looks promising (ability to define emphasis class for additional items such as foreign language indicator and so on), as a table maintainer and a contributor to a screen reader project, I would vote for us to move to 3.x.y version number (starting with 3.0.0).

Implementation strategy:

1. Once people see the new emphasis opcode branch in action and verify that it works as advertised, let's create a preliminary 3.0.0 branch (perhaps a 2.9.0 branch).
2. The pre-3.0.0 (or 2.9.0) branch will contain code that is destined for 3.0.0, namely emphasis work done by Mike and Davy, YAML test suite and other work contributed by developers.
3. We should wait at least one 2.6.x development cycle (three months) before declaring 3.0.0 as stable (I'd say at least six months to a year, or two to four 2.6.x dev cycles). During this time, we should educate table maintainers on how to write the new-style tables using the emphasis opcode format that's under active development (if this is adopted). This also allows users of LibLouis to test the new table format and report issues to developers.
4. LibLouis 3.x.y will be developed just like 2.6.x development process (release due every three months).

Possible issues to think about:

• Not all table maintainers speak English well, so there should be an extensive outreach program to let maintainers know about what's going on.
• It will take months for new table style to settle (more so now that we have at least three screen readers using libLouis).
• There should be a documentation informing people what's new, changed and removed between old and new table format, especially opcodes.
• LibLouis 3.0.0- proposal depends on successful adoption of emphasis opcode changes and other branches.

Thanks.

[dkager]

This is on the agenda. There's a small API change too, so some kind of version bump has to happen. My preference is 3.0.0. Also, I believe there are plans to release an alpha version soon (unless I get lost in this code again). The impact on table authors is relative, since some of these opcodes either didn't exist before or existed but were broken to the point where few tables used them, instead using e.g. multipass rules. On the other hand there are quite some renames and under-the-hood changes, so some break-in time will be required.

[bertfrees]

Thanks Joseph. The idea is indeed to move to 3.0.0, starting with a 3.0.0-alpha (not 2.9.0).

But are you suggestion we keep making 2.6.x releases in parallel to the 3.0.x releases for a few iterations?

[josephsl]

Hi Bert, I’d say for at least six months so people can transition to the new opcodes and such (maybe 2.6.7, announce 3.0.0, 2.6.8, 3.0.0 or a similar order). Thanks.

From: Bert Frees [mailto:notifications@github.com] Sent: Thursday, February 4, 2016 2:13 AM To: liblouis/liblouis liblouis@noreply.github.com Cc: josephsl joseph.lee22590@gmail.com Subject: Re: [liblouis] Set LibLouis version to 2.7.0 or 3.0.0 once emphasis overhaul and other work are implemented (#156)

Thanks Joseph. The idea is indeed to move to 3.0.0, starting with a 3.0.0-alpha (not 2.9.0).

But are you suggestion we keep making 2.6.x releases in parallel to the 3.0.x releases for a few iterations?

— Reply to this email directly or view it on GitHub https://github.com/liblouis/liblouis/issues/156#issuecomment-179749091 .

[egli]

The plan is to release a 3.0 alpha once the ueb stuff has been integrated