Organizing your codebase (deprecated)

Upgrading libraries to the latest version

There's no problem with having multiple versions of a library installed at once, though sometimes you want to upgrade to the latest version of a library and delete any references to the old version. There are a couple cases you can encounter here. If alice.mylib.v6 is a superset of alice.mylib.v5, this is as simple as just deleting the v5 after v6 is installed.

😎 Since references to definitions are by hash, not by name, any renaming of definitions done between v5 and v6 of a library won't break any of your code. Though we recommend reading the release notes to discover these sorts of changes, or using diff.namespace somelib.v5 somelib.v6 for an overview.

If v6 replaced any definitions with new ones (using the update command or replace.term or replace.type), these are recorded in a patch which can be applied locally.

As a norm, alice.mylib.v6.releaseNotes will cover how to apply patches to your local namespace. It will typically be commands like:

.myProject> branch main upgradeAliceLib
.myProject> patch external.mylib.v6.patches.v5_v6 upgradeAliceLib
.myProject> merge /upgradeAliceLib /main

Day-to-day development: creating and merging pull requests

Here's the basic workflow for drafting changes to main in your own project. It's not much different than a typical Git workflow, where you create branches, hack on them, then merge them to main when done:

1. myProject/main> branch main myCoolPR
2. myProject/myCoolPR> Now hack away. Use merge.preview main myCoolPR at any time to see what you've changed.
3. myProject/myCoolPR> merge /myCoolPR /main when you're done

To propose changes to another Unison codebase works similarly. We'll use the Unison base library as an example:

1. .> pull unison.public.base.main _base you can do this both for initial fetch and for subsequent updates
2. .> fork _base .prs.base._mything to create a copy of _base. You can create multiple forks in .prs.base, if you have multiple things you're working on.
3. If you haven't already done so, set your default license for .prs.base to match the license of the codebase you're contributing to. For base it's the MIT license.
4. Now cd .prs.base._mything and hack away as before. At any time review what's changed between your namespace and _base with diff.namespace ._base .prs. base._mything.
5. Push your forked version somewhere public with your Unison Share account. prs.base._mything> push myUser.public.prs.base._mything. No need to maintain a separate Git repo for every Unison library you want to contribute to.
6. .prs.base._mything> pull-request.create unison.public.base.latest myUser.public.prs.base._mything and this will create some output. Copy that output to your clipboard. We don't literally use the GitHub pull request mechanism for Unison repositories, we use GitHub issues instead.
7. Use the GitHub issue comments for coordinating the review. Once merged, the maintainer will close the issue.
8. Next, create a GitHub issue in the repo you're submitting the code to (that's right, an issue, not a GitHub PR). Many Unison repositories will have a GitHub issue template for this purpose. Make the issue title something descriptive, and for the issue body, paste in the output generated by

   pull-request.create` as well as some text describing the change, just like you would for any other pull request.
   
                                                                                                                                                                                                                                                                                               This workflow also works fine even if the source and destination repository are the same, so you might use the above PR process when suggesting changes to a library  that you maintain with other people.
   
                                                                                                                                                                                                                                                                                               ### Reviewing pull requests
   
                                                                                                                                                                                                                                                                                               We'll use [this issue as an example](https://github.com/unisonweb/base/issues/12). The issue created for the PR will have a

   pull-request.load'' command to review the PR locally. We'll run that command in any empty namespace:

.review.pr12> pull-request.load unison.public.base.main pchiusano.public.unisoncode.prs.random2

If you .review.pr12> ls you'll see three or four sub-namespaces: base (the original namespace), head (the new namespace), merged (the result of merge head base) and potentially squashed (the same content as merged but without intermediate history). The following commands can be performed against either the merged or squashed namespace, depending on if preserving history is important to you:

1. .review.pr12> diff.namespace base merged to see what's changed. The numbered entries in the diff can be referenced by subsequent commands, so diff.namespace base merged might be followed by view 1-7 to view the first 7 definitions listed there.
2. You can use comments on the GitHub issue to coordinate if there's any changes you'd like the contributor to make before accepting the PR. You can also make changes directly in merged.
3. .review.pr12> push unison.public.base.main merged to push merged to main
4. .review.pr12> history merged and copy the top namespace hash. That's the Unison namespace hash as of the merged PR. Then close the GitHub issue with a comment like "Merged to main in hash #pjdnqduc38" and thank the contributor. 😀 If you ever want to go back in time, you can say .> fork #pjdnqduc38 .pr12 to give the #pjdnqduc38 namespace hash the name .pr12 in your tree.
5. If you like, .> delete.namespace .review.pr12 to tidy up afterwards.

.> pull git(https://gitub.com/unisonorama/myproject) main

Using unreleased library versions

Sometimes, you want to use some code that's only in main of a library but hasn't made its way into a release. No problem. The install process looks the same, just do a pull:

.> pull https://github.com/bob/mylib:.main .external.bob.mylib.main

As often as you like, you can re-issue the above command to fetch the latest version of the library. After doing so, you should then apply patches from the library to your local namespace. Check the project's README for information on how to do this, but typically, for a namespace, bob.mylib.main, there will just be a patch called bob.mylib.main.patch which can be applied with:

.> fork main prs.upgradeBob
.> patch external.bob.mylib.main.patch prs.upgradeAliceLib

Assuming all is well after that patch, you can .> merge prs.upgradeBob main (and then sync that with any other PRs being drafted, as discussed in the previous section).

If you are feeling adventurous it's also possible to directly apply the patch to your in-progress PRs or even main.

How to create a release

Suppose you are creating v12 of a library. The process is basically to fork a copy of main:

0. Before getting started, we suggest reviewing the current patch in main with .> view.patch main.patch. The term and type replacements listed here should generally be bugfixes or critical upgrades that you expect users of your library to make as well. You can use delete.term-replacement and delete.type-replacement to remove any entries you don't want to force on library users. See below for more.
1. Fork a copy of main: .> fork main series._v12
2. The current dependencies in the release should be included in the library's lib namespace. This convention ensures that anyone who obtains the library also receives its dependencies and the naming for those definitions at the time.
3. Create or update series._v12.releaseNotes : Doc. You can include the current namespace hash of series._v12, a link to previous release notes, like releases. _v11 releaseNotes, and if the release has a non-empty patch, give some guidance on upgrading. Are all the edits type-preserving? If no, what sort of refactoring will users have to do?
4. squash series._v12 releases._v12 to create the release. This squashed releases._v12 will have no history and is more efficient for users to pull into their codebase.
5. • Reset the patch and release notes in main: .main> delete.patch patch and .main> delete.term releaseNotes. Anyone can upgrade from a past release v3, by applying the patches releases._v4.patch, releases._v5.patch up through releases._v12.patch.
   • • If desired, you can also produce cumulative patches for skipping multiple versions. These can be published on an ad hoc basis. If publishing these, just include them in releases._v12.patches.v4_to_v12.
6. Optional: you can add updated instructions for fetching the release to the the README on the repo's Unison Share page. You can also let folks know about the release via any other communication channels (Twitter, Slack, etc).

We don't recommend any fancy numbering scheme for versioning, just increment the version number. Use the releaseNotes to convey metadata and additional nuance about each release.

.mylib.trunk> view.patch patch

  Edited Terms: List.frobnicate#92jajfh197 -> List.frobnicate
  Edited Terms: CinnamonRoll#93jg10ba -> SugarCookie

  Tip: To remove entries from a patch, use delete.term-replacement or
       delete.type-replacement, as appropriate.