paredit breaks "." repeat command

[Wonko7]

Hi all!

I'm not sure if this is a problem on my side, but this happens when I add paredit to my config:

When I'm in the middle of a word and I change the end "ceTEXT":
wo|rd -> woTEXT
I expect . to do the same on other words:
oth|er -> othTEXT
Instead I get:
ohTEXTher

How come? Am I missing something?

[Wonko7]

I tried adding <c-g>U before every <Left> and <Right> but I still get the same problem. Any Ideas?

[kovisoft]

Thanks for the feedback. I confirm that this is a bug in paredit. Could you please test the following? Please locate this line in paredit.vim (line 139):

        nnoremap <buffer> <silent> cw           :<C-U>call PareditChangeSpec('cw',1)<CR>

and insert this line before that:

        nnoremap <buffer> <silent> ce           :<C-U>call PareditChangeSpec('ce',1)<CR>

Does this solve the problem?
Thanks for the assistance.

[Wonko7]

It does <3 thanks a lot!

[Wonko7]

Same thing for "ctX" and "cfX" (X being a character in the current word), do you want a separate issue for those?

[kovisoft]

I think we need a general solution for the c{movement} problem, but I'm not even sure it can be solved correctly for all possible movement types. For example let's assume the cursor is on a word containing X, then ctX replaces text until X, but what if we want to repeat this command on another word NOT containing X but X coming later on in the same line while there is a parenthesis between the cursor and the X character? If we simply repeat the command then we would remove the parenthesis and thus ruin the parenthesis balance.

Right now I see no perfect solution. I'm thinking about introducing a new option that would disable the paredit version of the c command, so it would behave the original vim-way. But I don't really like it because in this case it's the user's task to maintain parenthesis balance when using the c command.

Let's keep this issue open until I can find a general solution.

[Wonko7]

I love paredit for the c command, using vim as I'm used to without thinking about parens, I wouldn't disable it.

If there's no perfect way of doing this, I'm OK with a plugin not being perfect. From time to time I'll end up doing something that breaks parenthesis balance, toggle paredit, fix it, toggle it back on, end of story.

[kovisoft]

I was playing a little bit with operator mappings (set opfunc=) and the . repeat command. It seems that repeating works without problems when the given operator does everything in normal mode (e.g. the d operator just deletes text up to the specified motion). The problems happen with operators that also go into insert mode, like the c operator. For such operators vim repeats only the part that was executed in insert mode, so for c it does not repeat the delete part of the command. This seems to be a vim issue for me, but I try to find a workaround for that. The current workaround is that paredit.vim has extra mappings for c with some simple movements (like cw, cW, cb, cc, etc).

[Wonko7]

btw, count breaks c commands: c2e for example. Have you considered using tpope's vim-repeat?

[kovisoft]

Tpope's vim-repeat is actually supported if the user has it installed, see function RepeatableMap in paredit.vim.

On the original problem: I found this open vim issue #3126 that I believe is causing this bug in paredit. The problem in vim is that when an operator function (opfunc) is used and that function mixes normal mode and insert mode commands (like the c command that deletes some text and inserts some new text), then the dot (.) operator repeats only the insert mode part. I tried to find a workaround, but no success so far. So as you suggested, tpope's vim-repeat can be a workaround right now.

[Wonko7]

In the meantime I've added these:

        nnoremap <buffer> <silent> cB           :<C-U>call PareditChangeSpec('cB',0)<CR>
        nnoremap <buffer> <silent> ce           :<C-U>call PareditChangeSpec('ce',1)<CR>
        nnoremap <buffer> <silent> cE           :<C-U>call PareditChangeSpec('cE',1)<CR>
        nnoremap <buffer> <silent> ca{          :<C-U>call PareditChangeSpec('ca{',1)<CR>
        nnoremap <buffer> <silent> ci{          :<C-U>call PareditChangeSpec('ci{',1)<CR>
        nnoremap <buffer> <silent> ca}          :<C-U>call PareditChangeSpec('ca}',1)<CR>
        nnoremap <buffer> <silent> ci}          :<C-U>call PareditChangeSpec('ci}',1)<CR>
        nnoremap <buffer> <silent> ca[          :<C-U>call PareditChangeSpec('ca[',1)<CR>
        nnoremap <buffer> <silent> ci[          :<C-U>call PareditChangeSpec('ci[',1)<CR>
        nnoremap <buffer> <silent> ca]          :<C-U>call PareditChangeSpec('ca]',1)<CR>
        nnoremap <buffer> <silent> ci]          :<C-U>call PareditChangeSpec('ci]',1)<CR>
        nnoremap <buffer> <silent> ca(          :<C-U>call PareditChangeSpec('ca(',1)<CR>
        nnoremap <buffer> <silent> ci(          :<C-U>call PareditChangeSpec('ci(',1)<CR>
        nnoremap <buffer> <silent> ca)          :<C-U>call PareditChangeSpec('ca)',1)<CR>
        nnoremap <buffer> <silent> ci)          :<C-U>call PareditChangeSpec('ci)',1)<CR>
        nnoremap <buffer> <silent> ci'          :<C-U>call PareditChangeSpec("ci'",1)<CR>
        nnoremap <buffer> <silent> ca'          :<C-U>call PareditChangeSpec("ca'",1)<CR>
        nnoremap <buffer> <silent> ci"          :<C-U>call PareditChangeSpec('ci"',1)<CR>
        nnoremap <buffer> <silent> ca"          :<C-U>call PareditChangeSpec('ca"',1)<CR>
        nnoremap <buffer> <silent> c%           :<C-U>call PareditChangeSpec('c%',1)<CR>

but c% doesn't work, do you have an idea for a quick fix or should I just do without?

[kovisoft]

That's because PareditChangeSpec tries to avoid touching the matched characters (parens, double quotes). Therefore it first moves the cursor away from those characters, and then applies the operator that is supplied in the first argument. What does it mean for c% when the cursor is on the opening paren? It first moves the cursor right until it is not on a matched character. Then it applies c%, but in this case % moves the cursor to the left paren (and not to the right one, as you would expect).

I suggest that you try this mapping for c%:

nnoremap <buffer> <silent> c%           :<C-U>call feedkeys('c%','n')<CR>

[Wonko7]

Perfect!
Now, don't get mad, but this works for me: https://github.com/Wonko7/paredit/blob/7f32fcf0395031d0e0efb0f5fb25a02429cb23b9/plugin/paredit.vim#L175

[kovisoft]

Then why don't you just remove the :set opfunc=PareditChange<CR>g@ mapping and revert to the original vim c operator? Your mappings practically do the same, they just call the original vim c function, therefore they don't keep the paren balanced state. For example c;, ct, cf, etc may delete a parenthesis if there is one between the current cursor position and the next search character.

[Wonko7]

Because I use that feature heavily.
I use ctX changes mostly for in word modifications, no need for paren balancing.
But being able to C-whatever, keeping parens balanced, and having a reliable repeat command, is exactly what I was looking for.