Text object movement

[Julian]

Hey!

@JosephFerano noticed on a vim-textobj-variable-segment ticket that there are parameters to plugin that allow defining a function / pattern for moving to the next text object.

I've been playing around a bit with trying to hook that up, but haven't had much success, and can't really find any other text objects that use move-[n|p](-function).

From the docs, it seems like the API these functions are supposed to return is the same as the select functions, i.e. type, start_position, end_position, but I'm not sure I see how that should be necessary – it seems like move-n should want type, end_position and move-p should want type, start_position, and further, it seems like they should not really need defining separately, they're inferable from the select functions. Have I misunderstood something?

(If I add a move-n-function which is just my select-a-function I see something happen, the appropriate range looks like it's being found, but oddly, I just see it get visual selected, and the cursor doesn't keep moving if I keep move-n'ing.)

[JosephFerano]

So I guess no progress has been made here? I miss this feature from Sublime :(

[kana]

Sorry for a late response. And sorry about the document. The current document is wrong. There is no support for move-[npNP]-function at the moment. Also the current implementation is wrong as you described. move-[npNP]-function acts like select-[ai]-function. I'll review the move-[npNP]-function specification later.

[Julian]

Cool, thanks for confirming -- I haven't taken a closer look at this since the original ticket, but I can if I can be of any help.

[kana]

From the docs, it seems like the API these functions are supposed to return is the same as the select functions, i.e. type, start_position, end_position, but I'm not sure I see how that should be necessary – it seems like move-n should want type, end_position and move-p should want type, start_position, and further, it seems like they should not really need defining separately, they're inferable from the select functions. Have I misunderstood something?

Almost right. But move-n means a command to move the cursor to the first character of the next text object, so that it requires start_position.

And generally move-[npNP]-function are not inferrable from select-[ai]-function. For example, vim-textobj-variable-segment's s:select_i searches a left boundary then searches a right boundary. It mostly selects the text object under the cursor, but sometimes selects the nearest text object before the cursor if the cursor is between two WORDs like foo {cursor} bar. Since move-n-function requires start_position of the text object next to the cursor, vim-textobj-variable-segment's s:select_i is not reusable as move-n-function.
(I just took a quick look the implementation of vim-textobj-variable-segment for the example. I might misunderstand about the exact behavior of s:select_i. But I think select functions usually have similar problems.)

[Julian]

Awesome. I'll see if I can try and give this another shot at some point.