How to replace a pair of brackets

Question

I have a file, containing some lines like this: aaa bbb (ccc) ddd.

Now I want to replace the pair of brackets by a pair of square brackets to make this line become aaa bbb [ccc] ddd.

I think that \ze and/or \zs might be used but I don't know how.

Answer 1

You can do it in a single substitute command like this

:s/(\(.*\))/[\1]/

The \( and \) mark the regex subexpression that matches everything inside the ( and ) in the input line. In the replacement, the \1 stands for whatever the first (in this case the only) marked subexpression matched.

In words you might describe the substitute command as: look for a "(" followed by anything followed by ")". Replace that by "[" followed by the same "anything" followed by "]".

Answer 2

With tpope/vim-surround, this is a simple

cs)]

away in Normal mode.

• cs is the "change-surrounding" operator
• ) is the "target"
• ] is the replacement

Answer 3

You can use this simple :s command (or better two :))

:s/(/[/g
:s/)/]/g

You can even do it in one run, you you define your replacements first like this:

:let replace={'(':'[', ')':']'}
:s/[()]/\=replace[submatch(0)]/g

Here we first define a dictionary with the keys of what you want to have replaced. So we need a key ( with the value [ since that is the replacement char you want. Also we want the key ) wit the value ].

Then we can use a sub-replacement-special to have the replacement character dynamically evaluated using the provided replace dictionary.

Answer 4

If that your cursor is on the left brace that you want to change:

%r]^Or[

If your cursor is on the right brace:

%r[^Or]

Basically, ask vim to find the matching brace, change it, then jump back to the first brace and change it too.

If your cursor is near enough to one of the braces you want to change, then you can do much as the above but double the initial %:

%%r]^Or[

Or

%%r[^Or]

This works across multiple lines, and with nested brackets.

You may even find it works with xml or html, depending on various things.

Answer 5

No need for a plugin, just apply the substitution command:

:%s/(\(\([^()]\|\n\)*\))/[\1]/g

Notes

• Supports multiple matches per line: (aa) (bb) -> [aa] [bb]
• Supports multi-line content: (aa \n bb) -> [aa \n bb]
• Supports nested parenthesis: ((aa)) -> ([aa])
• Doesn't change unmatched characters: a) (b) -> a) [b]
• However it needs to be applied multiple times manually to substitute the outer parenthesis: ([aa]) -> [[aa]].

Breakdown of the command

• :%s/ for all lines, substitute the pattern:
• ( start pattern with opening parenthesis
• outer \(...\) so that the content can be referred as \1 later
• inner \(...\)* any number of matches of ...
• [^()] any character that is not ( or )
• \|\n or a line break to allow multi-line patterns
• ) last character of the search pattern
• /[\1] substitute by [ \1 = content form first \(...\) in the pattern ]
• /g globally, so any number of substitutions per line

Notes

• I hope I didn't get a typo now...
• If the command is too long to be remembered, it might be mapped to a key.
• If stored as a function, it might be called n times in one call to substitute nested parenthesis. To be honest, I don't know functions, someone might want to comment on that.

Answer 6

Beside tpope/vim-surround, there is another good plugin called vim-sandwich that can add, replace and delete surround pairs of characters:

With vim-sandwich, you can use srb] or sr)] to replace a pair of () to []:

• sr: start to replace sandwiched text
• ) or b: the character pair you want to replace, (you use b when there is no ambiguity which pair you want to replace)
• ]: the character pair you want to use

Answer 7

You only have to capture the inner part:

:s/\((.*)\)/[\1]/

I tried this and works on Python. If I do as @magikarp, the parenthesis does not disassapear. To fix it, you have to capture only the inner part.

Instead of

re.sub(r"(\(.*?\))",r"[\1]",x)

it has to be

re.sub(r"\((.*?)\)",r"[\1]",string)