regexp warning in String.split?

[Chris Morris]

irb(main):001:0> 'a,b'.split(',')
=> ["a", "b"]
irb(main):004:0> 'a => b'.split(' => ')
(irb):4: warning: string pattern instead of regexp; metacharacters
no longer eff
ective
=> ["a", "b"]

Why do I get a warning on the second split call?

 

[Brian Candler]

irb(main):001:0> 'a,b'.split(',')
=> ["a", "b"]
irb(main):004:0> 'a => b'.split(' => ')
(irb):4: warning: string pattern instead of regexp; metacharacters
no longer eff
ective
=> ["a", "b"]

Why do I get a warning on the second split call?

Because you should be using:

'a => b'.split(/ => /)

(I don't think '=' or '>' by themselves has significance in a regexp, but in
combination they might do - if you use odd things like assertions)

Cheers,

Brian.