Question

I am trying to create a regex that helps Eclipse’s search find all lines that contain start( except for ones that are comment lines.

That is, find lines like:

 is not sufficient because it doesn't guarantee that start(b) is 

But not lines like:

 * is not sufficient because it doesn't guarantee that start(b) is

I have been able to come up with the regex (\s*?)(?!\*)(.*)(start\()(.*$) but it finds both lines.

How do I exclude the line that starts with * (possibly after some whitespace) and include lines that don’t have that?

Answer 1

For a line beginning with whitespace, it would be possible for the \s*? to match zero whitespaces, then the (?!\*) to match a whitespace, and the .* trailer to match the rest of the line including asterisk.

A solution would be to put the leading-whitespace preamble inside the negated clause:

^(?!\s*\*).*start\(.*$

Alternatively you could use a possessive quantifier to eat all the whitespaces and never backtrack:

^\s*+(?!\*).*start\(.*$