Expand selection to whole word when pressing *

[magopian]

Closes #6045

This is an attempt at adding the functionality discussed in this issue (and earlier on matrix).

I'm open to suggestions, I've barely learned Rust, and it was a long time ago and seldom used it, so i'm very... rusty.

Please let me know if this is useful, relevant, and how it could be improved!

[pascalkuthe]

I like this change and the implementation looks reasonable to me too as its just lifted from goto_file 👍

Searching for a single char with * seems like a nieche use-case: *n it not much shorter than /[char]<ret> or f[char].
Automatically using the word under the cursor is consistent with gf and can be super useful.

However this behavior change should be documented in keymap.md .
Currently it says:

Use current selection as the search pattern

Wit this PR something like the following would help:

Use current selection as the search pattern, if only a single char is selected the current word (miW) is used instead

[magopian]

Thanks for the feedback, I've updated the keymap.md file accordingly 👍

[pascalkuthe]

LGTM now 👍

[firstrow]

nice improvement. going to test it locally. currently was using this config:

"*" = ["move_prev_word_start", "move_next_word_end", "search_selection", "global_search"]

[ubitux]

I think it makes sense to encapsulate the word between \b to prevent overmatching

[the-mikedavis]

I was initially opposed to this behavior (along these lines: #6045 (comment)) but with the special registers from #6985 you can search for the current selection exactly with /<C-r>.. So I think this would be a nice improvement. I left a few small comments and pushed up a merge with master since there were some changes from the special registers PR that conflicted

[the-mikedavis]

Passing false here makes this look for the surrounding "word" rather than the "WORD". I think that's an ok behavior but the change in book/src/keymap.md should mention miw instead of miW. Also see

helix/helix-term/src/commands.rs

Lines 5000 to 5001 in d570c29

	'w' => textobject::textobject_word(text, range, objtype, count, false),
	'W' => textobject::textobject_word(text, range, objtype, count, true),

[the-mikedavis]

I believe what's happening here is that collecting into a hashmap might change the order. The selections do have a deterministic order

[shaleh]

The source code could add the itertools crate and then use unique on the iterator instead of collecting twice. unique is stable.

[the-mikedavis]

I believe Kakoune also adds \b in some cases with *. I think it would be a nice improvement to move our * closer to Kakoune's behavior - though that should be a follow-up PR