Making searches more efficient: Backtracking

• Using quantifiers can be quite time consuming if they don't help immediately make the match

  	"aaaaaaaaab" =~ /a*a*a*[b]/

  succeeds pretty quickly, but

  	"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" =~ /a*a*a*a*a*a*[b]/

  will take a fairly long time to fail.
• You can specify not to give up characters and re-evaluate the pattern with (?>pattern)
• Note that when using this, it will never give up characters.

  	"aaaaaaaaaab" =~ /(?>a*)ab/

  will fail