The last use of _, as in empty_?, is not a special scala meaning. As on Java, 
underscores can be part of an identifier. Scala takes advantage of this to 
combine letters and symbols in one name. These names, like empty_?, are a Lift 
convention, as well as ..._! for use-with-care methods. The scala library uses 
isEmpty. David, is it your original convention?.

tiro<> wrote:

> override def validations = validPriority _ :: super.validations
funny, I had stumbled on exactly the same line of code when beginning.
Took me more than a day to understand what's going on. Especially
because when you copied code from the PDF version of the Liftbook/Lift
getting started guide, it would mess up spaces, so I would keep
loooking for a "_::" operator.
The Scala guys have really pushed it a bit hard on the use of the
underscore. At least four different uses:
- "it" for defining anonymous functions like above
- default value
- matching placeholder whose value is ignored
- use for constructing setter method names boolean functions (empty_?)

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