Format text lines

[ricksladkey]

Changes

• Rename functions associated with = formatting to be named FormatCodeLines
• Add a new common operation to format text lines called FormatTextLines
• Add gq and gw operations to format text lines in visual mode
• Add gqgq, gqq, gwgw and gww operations to format text lines in normal mode
• Add textwidth setting defaulting to 0
• Add comments setting defaulting to line comments in C, C++, C#, F#, Java, Javascript, Python, Lisp, Shell

Fixes

• Fixes gq doesn't format text #333

Discussion

This is a "bare-bones" implementation of formatting text lines that omits many of the more esoteric vim features but adds the crucially missing capability to intuitively reformat comments in the most used programming languages. Subsequent more ambitious PRs can address the missing functionality.

Limitations

• The formatoptions variable is not implemented
• None of the comment specification flags in comments are implemented
• Tabs in the leader are properly accounted for but tabs in the text are not
• All the lines being formatted in one operation must have the same leader
• gw is currently the same as gq, i.e. it doesn't preserve the caret position

[ricksladkey]

I'm already using this every day! So nice...

[jaredpar]

Why 79?

[ricksladkey]

That's what the vim documentation says it uses if textwidth is zero!

If the 'textwidth' option is 0, the formatted length is the screen width (with a maximum width of 79).

I guess the idea is that it wraps at 80 columns but makes a concession for terminals that "double-wrap" the line if it is exactly 80.

Also, from this documentation you can see that I did not limit the width to the screen width, which doesn't seem to be a reasonable setting to use with Visual Studio where the user has virtually no control over the width of the window.

[jaredpar]

Can we get a comment for the magic number 79? Other than that this looks great.

[ricksladkey]

Moved the magic number to VimConstants with a comment.