http://www.perlmonks.org?node_id=558887


in reply to The craziest RegExes you ever created

Not really the craziest I've ever made, but certainly one of my more creative ones can be found here.

The regex is:

/([^~])[^~]*([^~]).*~[^~]*([^~])[^~]*([^~])(?{local$z=$1 and local$y=$ +2 and local$x=$1 eq$3?$4:$1 eq$4?$3:($z=$2)&&($y=$1)&&$2 eq$3?$4:$2 e +q$4?$3:0}).*~[^~]*((??{$y})[^~]*(??{$x})|(??{$x})[^~]*(??{$y}))(?{$x{ +join" - ",sort$x,$y,$z}++})(?!)/

Basically I used the regex engine to search through all the possible triangles and failed everytime I found one so I could continue searching for the rest.