Vim fu, swapping parameters for a method call

vim

What is the most efficient way to swap two params for a method call in Vim?

For example, I want to change:

call "hello mister 123", 2343

to:

call 2343, "hello mister 123"

(Assume the cursor is at the beginning of the line.)

Ideally the trick works for stuff like

call "hello, world" , "goodbye, world"

Best Solution

This regex will do it for your examples:

:s/\vcall ("[^"]+"|[^,]+)\s*,\s*("[^"]+"|[^,]+)/call \2, \1/

This regex will need to become progressively more nasty if you have escaped quotation marks and such things in one of your parameters.

In reality, I'd just highlight one parameter (in visual mode), hit d, highlight the other parameter, and hit p; Vim will nicely paste what's in the register, overwriting what you have highlighted, and swap the deleted text into the register. Then move the cursor and hit p again. Highlight, d, highlight, p, move cursor, p is a common combination, in my vimming at least.

So with the cursor at the start of the line, first example:

wva"dlvawpF,P

Meaning move past the word "call" (w), highlight a quoted string (va"), delete it (d), move one space to the right (l), highlight a word (vaw), paste (p), move backward to the comma (F,), paste before it (P).

Second example:

wva"dlva"p_f,P

This isn't hard once you get used to the movement commands.

Use `\r` instead of `\n`.

Substituting by \n inserts a null character into the text. To get a newline, use \r. When searching for a newline, you’d still use \n, however. This asymmetry is due to the fact that \n and \r do slightly different things:

\n matches an end of line (newline), whereas \r matches a carriage return. On the other hand, in substitutions \n inserts a null character whereas \r inserts a newline (more precisely, it’s treated as the input CR). Here’s a small, non-interactive example to illustrate this, using the Vim command line feature (in other words, you can copy and paste the following into a terminal to run it). xxd shows a hexdump of the resulting file.

echo bar > test
(echo 'Before:'; xxd test) > output.txt
vim test '+s/b/\n/' '+s/a/\r/' +wq
(echo 'After:'; xxd test) >> output.txt
more output.txt

Before:
0000000: 6261 720a                                bar.
After:
0000000: 000a 720a                                ..r.

In other words, \n has inserted the byte 0x00 into the text; \r has inserted the byte 0x0a.

Best Solution

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Use \r instead of \n.

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Use `\r` instead of `\n`.