Question

I need a macro/function that searches the current document, starting at the top, for a specific pattern. Stopping at the first line that isn’t commented out.

For example in this vim script:

"This is the first line

"This is the third line

if exists("did_something")

It would stop at if line, return true if it found the pattern and false otherwise.

All help appreciated!

Answer 1

Let’s say your pattern is the letter ‘e’.

To search for a line that is not commented out, but contains an e:

 /^\%(\s*"\)\@!.*e

This uses a negative lookahead (\@!) to confirm that the start of the line (^) isn’t followed by a the beginning of a comment (whitespace and then a double quote \s*") but is followed by an ‘e’ (.*e). The \%( and \) makes the enclosed pattern an atom that other operators (like negative lookahead) can operate on as a unit.

To run a command on matching lines, use :g

 :g/^\%(\s*"\)\@!.*e/echo "found one"

To see if the current line matches, use match()

 :echo match( getline(line('.')), '^\%(\s*"\)\@!.*e' ) >= 0 ? 'true' : 'false'

The regex is pretty much always the same, the question is what do you want to do with matching lines?