Is there a motion to select the comment block under the cursor?

Question

One thing that I often need to do is reformat a code comment with gq or gw. For example, I often want to convert something like this:

// Lorem ipsum 
// dolor
// sir 
// amet
int foo(int x) {
    return 17;
}

into this:

// Lorem ipsum dolor sir amet
int foo(int x) {
    return 17;
}

Is there a vim motion I can use to select the entire comment block under the cursor? I tried using gq} and gqipbut they also reformat the code under the comment, which is too much.

// Lorem ipsum dolor sir amet
int foo(int x) { return 17; }

So far the best I could think is manually counting lines, using something like gq4j. But there ought to be a better way...

Answer 1

If using plug-ins is acceptable to you, then the vim-commentary plug-in can help you.

It defines a gc text object to select a comment, which you can use in operator pending mode. Use gqgc anywhere in the comment block to format the comment.

Note that if you are using C or C++ you may need to tell Vim to use // comments instead of /**/ comments. You can define either the 'commentstring' option or alternatively the b:commentary_format buffer variable.

set commentstring=//%s