Hi...

given: String of several Mb
problem: find the lines in String containing "xyz"


Idea 1:
String.scan(/.*xyz.*/) -> ~10s runtime

Idea 2:
String.grep(/.*xyz.*/) -> ~3s (but gives the \n too)

Idea 3:
loop String.index("xyz",lastmatch+3)
loop results array and grep in match area for line
-> 0,5s


C extension the only faster option left? :-)

Martin