A search on “overlapping matches’ in perldoc doesn’t turn up anything relevant. However, I did find the following in the Camel Book (4th Edition, pages 247–8, underlining added):

Lookahead assertions can be used to implement overlapping matches. For example, 
    "0123456789" =~ /(\d{3})/g

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returns only three strings: 012, 345, and 678. By wrapping the capture group with a lookahead assertion: 
    "0123456789" =~ /(?=(\d{3}))/g

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you now retrieve all of 012, 123, 234, 345, 456, 567, 678, and 789. This works because this tricky assertion does a stealthy sneakahead to run up and grab what’s there and stuff its capture group with it, but being a lookahead, it reneges and doesn’t technically consume any of it. When the engine sees that it should try again because of the /g, it steps one character past where last it tried.

HTH,

Athanasius <°(((>< contra mundum

In reply to Re^4: Regex Greed by Athanasius
in thread Regex Greed by temporal

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