Bug while changing inside angle-braces

[kshenoy]

This is my code

nnoremap <A-f> [I:let nr = input("Find: ")<Bar>exe "normal " . nr ."[\<C-I>"<CR>

My cursor is on the dash in <C-I>. If I type di<, the line changes to

nnoremap <A-f> [I:let nr = input("Find: ")<Bar>exe "normal " . nr ."[\<C-I>"<>

instead of

nnoremap <A-f> [I:let nr = input("Find: ")<Bar>exe "normal " . nr ."[\<>"<CR>

as expected.

[wellle]

Thank you for your report. I can reproduce it and found that the reason for this lies in Vim itself.

To confirm, try this. Start Vim without settings and plugins:

vim -u NONE --noplugins

Enter the text \<x>, place your cursor on x and type di>. Vim doesn't delete the x. Try the same without the backslash <x> and it works. I am using these stock text objects in targets.vim, so this behavior gets forwarded to you.

---

Here are some internals I found in case you are interested:

The command di> triggers a call stack including the following calls:

1. nv_object
2. current_block
3. findmatch
4. findmatchlimit

The findmatchlimit call searches for the opening < left to the cursor. It also recognizes that there is a backslash in front of the bracket \< and basically rejects it. The cpoptions flag M can normally be used to ignore these backslashes and I would have advised you to try this setting. Unfortunately the calling function current_block overwrote cpoptions="%" before calling findmatch to make findmatchlimit ignore certain brackets in quoted strings. This is all reasonable, but it also means that adding M to your cpoptions couldn't help here.

---

In summary the behavior your observed is the result of Vim's very internals. I would guess that a lot of thought went into these details over the years, so I'm not sure we want to fiddle with it.

The idea behind all this is documented in :help cpo-M and :help cpo-%.

If you're still not convinced I would recommend to address this on vim_dev and propose to set cpoptions to %M or % depending on whether or not M was part of the original cpoptions string. That way you could :set cpo+=M locally and everything should work for you. But I don't know about other implications that change in Vim's core would have for everybody else.

[kshenoy]

Thanks for the digging into it. You're correct; my apologies for not trying it out on a stock setup.

[wellle]

No worries. I learned some new Vim internals :)