How to use non-greedy correctly?

wjswanepoel · PostMar 10, 2023#12023-03-10T10:39+00:00

How do I make the search pattern <SP (.+:)> non-greedy so that it picks up in

<SP Hy:> Ek kom na my tuin,<CI><PI2> my suster, my bruid.<CI><PI> Ek pluk my mirre met my speserye,<CI><PI> ek eet my heuningkoek<CI><PI2> met my heuning,<CI><PI> ek drink my wyn met my melk.<SP Koor:><CI><PI> Eet, vriende!<CI><PI> Drink, en word van liefde dronk!<CM>

just <SP Hy:> and on next search just <SP Koor:> and not everything from <SP Hy:> to <SP Koor:>?

I have tried everything I could think of, to no avail.

Mofi · PostMar 10, 2023#22023-03-10T16:30+00:00

There can be used as search expression either <SP (.+?:)> or <SP ([^:]+:)> which both stop matching characters on next colon and the first one also on newline characters like carriage return and line-feed. ? after a multiplier like * or + means non-greedy, see Repetition with Star and Plus and best also Possessive Quantifiers.

fleggy · PostMar 11, 2023#32023-03-11T09:22+00:00

Just be careful because ? itself can be used as a quantifier as well. Personally, I suggest to think of quantifiers in this way:

greedy

*	any to 0
+	any to 1
?	1 to 0
{n,m}	m to n

non-greedy

*?	0 to any
+?	1 to any
??	0 to 1
{n,m}?	n to m

I believe It helps to better understand how the regexp engine works.

BR, Fleggy