Steven Watanabe:
Joel de Guzman wrote:
Yep. Phoenix can do that. A local variable may hide an outer local variable. Here, we just reuse the locals for arguments to the lambda as well. So, in current terms, this:
lambda( _x, _y )[ _x + _y ]
is just this:
lambda( _x = _1, _y = _2 )[ _x + _y ]
Am I misunderstanding something? I thought that this would give lambda( _x = _1, _y = _2 )[ _x + _y ] (1, 2)() == 3 instead of lambda( _x = _1, _y = _2 )[ _x + _y ] ()(1, 2) == 3
Under the model I have in mind: lambda( _x, _y )[ _x + _y ] ( 1, 2 ) == 3 That is, lambda is not lazy, and it doesn't compose further. lambda( _x )[ _x ] + _1 doesn't compile; there's no operator+ taking a lambda.
I don't think it is quite the same if you use an arbitrary expression instead of _x + _y. For instance, what should this mean:
lambda(_x, _y) [ _x + _y + _1 ]
If we're allowed to not think about backward compatibility, I'd say that _1 would no longer exist. Not even at top level.