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Rici Lake wrote:

Brian Hagerty wrote:
Notice that the "hidden" parameter idiom of colon-functions does not provide another place for you to create a different name for that hidden parameter. 

Sure it does. Just don't hide it. (See below).
It is true you can always "not hide" a hidden parameter, in which case it's not a hidden parameter "method" call at all, and it would use the colon operator.
But Gary Ng's original question was about renaming the hidden parameter in a *colon-defined* function. In that case 'self' is the only allowed name for the truly hidden parameter. 


Yes, but I could easily write this:

function Account.deposit(foo, v)
  foo.balancer = foo.balance + v
end

That sort of thing is often useful: you don't always want to call
a function with the table it lives in (sometimes you want to call
it with another object in the chain, for example.)
That is very useful, and is always an available dot-function idiom. But that doesn't reflect a purely colon-defined instance-method idiom (where the method is implicitly applied to the caller). That dot syntax defines a more generalized (not specifically OO) functional idiom with an arbitrary object as first argument.
The original question was whether the colon-defined function syntax was necessary. Dot-defined function examples add to the case for obviating the need for colon-defined functions. 

// Brian