Common root logic is ignored

[tekumara]

When there's a common root, z chooses the shortest matching directory as I expect:

$ cat ~/.z
/Users/tekumara/code/setup|1250.4200000000001|1593232602
/Users/tekumara/code|223.405|1593230323

$ z code -l
common:    /Users/tekumara/code
737.07     /Users/tekumara/code
5002.87    /Users/tekumara/code/setup

However, the common root logic isn't applied in the following case, which gives the surprising behaviour of choosing the more frequent directory:

$ cd ~/.vscode/extensions
$ cat ~/.z
/Users/tekumara/code/setup|1252.4200000000001|1593232621
/Users/tekumara/code|223.405|1593230323
/Users/tekumara/.vscode/extensions|1|1593232655

$ z code -l
7.98       /Users/tekumara/.vscode/extensions
733.93     /Users/tekumara/code
4983.06    /Users/tekumara/code/setup

I was still expecting /Users/tekumara/code to win, despite the addition of the vscode directory.

FYI: rupa/z has the same behaviour.

[agkozak]

You're quite right - that is the behavior of rupa/z, and since zsh-z is for the most part a drop-in replacement for rupa/z, the results should be the same.

The underlying reason is that in the second instance, where you're searching for code and the possible matches are

/Users/tekumara/.vscode/extensions
/Users/tekumara/code
/Users/tekumara/code/setup

there is not really a common root. There would only be a common root if all the matches started with /Users/tekumara/code. The presence of a possible match that is not "common" means that the "common directory" logic does not apply.

I am working on an alternate way for zsh-z to pick out the best match in the no-subdirectories branch, which I encourage you to switch to and try out. You can read about its development here, but the basic idea is that if the best match is /Users/tekumara/code/setup and you'd typed z code, you'd end up in /Users/tekumara/code -- the experimental code just drops any subdirectories of the best match that do not contain the search text in them. If you'd typed z set, then, and the best match had also been /Users/tekumara/code/setup, you'd end up in /Users/tekumara/code/setup, since set was what you were looking for.

The new behavior appears to work well, and I've got a number of people testing it out. If it continues to be a success, I'll merge it into the master branch as an alternative method that can be enabled by setting an environment variable. Try it and let me know what you think.

[agkozak]

Actually, I've decided that the new feature is mature enough to be on the master branch. So use that, but include

ZSHZ_UNCOMMON=1

in your .zshrc.

[tekumara]

Thanks @agkozak I'm using zsh-z.plugin.zsh on master (0d1f65a) but don't see any differences in behaviour:

$ echo $ZSHZ_UNCOMMON
1

$ z code -l
7.91       /Users/tekumara/.vscode/extensions
150.49     /Users/tekumara/code
856.32     /Users/tekumara/code/setup

$ echo $ZSHZ_UNCOMMON


$ z code -l
7.91       /Users/tekumara/.vscode/extensions
150.49     /Users/tekumara/code
856.30     /Users/tekumara/code/setup

[agkozak]

The new, alternate behavior (when you set ZSHZ_UNCOMMON=1) doesn't change the ranking of the possible matches. It changes where you end up if you simply type z code.

In your example, if you set ZSHZ_UNCOMMON=1 and type z code, ZSH-z picks the highest-ranking match (Users/tekumara/code/setup) and drops the /setup subdirectory (ZSH-z will keep dropping subdirectories until it arrives at the text you were actually searching for). So you end up in /Users/tekumara/code,

If you use the default "common prefix" method, well -- there is no common prefix. You only have a common prefix when all of the possible matches start with the same letters, and the presence of /Users/tekumara/.vscode/extensions in the database prevents that from happening. So there's no common directory to jump to, and ZSH-z simply sends you to the highest-ranking match: /Users/tekumara/code/setup.

[tekumara]

OIC thanks for helping me understand! I didn't realise the new logic was applied on top of the scoring.

So as you say, with ZSHZ_UNCOMMON=1, then z code takes me to /Users/tekumara/code as I'd like instead of /Users/tekumara/code/setup.