On Sat, Jan 15, 2022 at 1:57 AM SZEDER Gábor <szeder.dev@xxxxxxxxx> wrote: > > On Mon, Jan 10, 2022 at 06:59:51PM +0000, Lessley Dennington via GitGitGadget wrote: > > Subject: Re: [PATCH v3 2/3] sparse-checkout: custom tab completion > > None of these patches touch sparse-checkout, but only the completion > script and its tests. Therefore "completion:" would be a better > matching area prefix. Thanks for the detailed feedback and guidance in your review. Very helpful. I'll omit quoting most of it here, but I do want to comment on the point about directories. ... > > 4. A list of directories (but not files) is provided when users enter git > > sparse-checkout add <TAB> or git sparse-checkout set <TAB>. > > Why limit completion only to directories? Both of those subcommands > accept files, Discussed in part at [1], but let me give a more detailed answer. Both of these commands accept not only directories and files, but also nearly arbitrary input as far as I can tell. (In cone-mode, it'll accept anything so long as it doesn't look like a relative path that tries to reach above the toplevel directory with '../' sequences. In non-cone mode, I think it accepts completely arbitrary input). If our guide is merely what the command swallows, then we should forgo completion for these subcommands, because it's not possible to enumerate all possible completions. I don't think that's a useful guide or starting point, so we instead need to discuss what are reasonable completions. cone-mode works exclusively on directories. So, in that mode, directories are what we want to complete on. (And if a file is specified, cone-mode will treat it as a directory and add expressions for including all the files under that "directory", which might be confusing. sparse-checkout doesn't verify it is a diretory, because it *might* name a directory in a different branch, including one not yet downloaded. But "might name a directory on another branch" is no reason to suggest picking that pathname with completion.) In non-cone mode, arbitrary expressions are valid and will be treated as gitignore-style expressions. That again leaves us with either not providing completions, or choosing a subset of possible inputs that are reasonable suggestions for users. I prefer the latter, and in particular I feel that directories are reasonable suggestions. In contrast, I don't think providing files is helpful, because it reinforces the design flaw of non-cone mode. Non-cone mode has quadratic performance baked into its design, and since sparse-checkouts are about performance, non-cone mode kind of defeats the purpose of the command. (In addition to other problems[2].) So, I think non-cone mode should be deprecated and excised. Patches elsewhere are moving in the direction of deprecation already[3], and we've already discussed multiple steps we'll likely take soon continuing in that direction. In the meantime, providing just directories for completion seems like a good direction to me. [1] https://lore.kernel.org/git/CABPp-BG=wr81CPtW1M12xFN_0dyS8mAZjM6o=77LA20Zge8Xng@xxxxxxxxxxxxxx/ [2] https://lore.kernel.org/git/CABPp-BF=-1aZd=nFHF6spo7Ksa7f7Wb7ervCt0QvtNitMY=ZBA@xxxxxxxxxxxxxx/ [3] https://lore.kernel.org/git/0af00779128e594aff0ee4ec5378addeac8e88a2.1642175983.git.gitgitgadget@xxxxxxxxx/ ("This mode is harder to use and less performant, and is thus not recommended.") > and I think 'git sparse-checkout set README.md' is a > perfectly reasonable command. Reasonable in what sense? That it makes it (vastly) easier to implement the completion and sparse-checkout set|add will swallow it, or that it's something that should actually be recommended for users doing sparse-checkouts? While the former certainly holds, I don't think the latter does.
