Values and objects

[Rustom Mody]

On Saturday, May 10, 2014 2:39:31 PM UTC+5:30, Steven D'Aprano wrote:
> 
> Personally, I don't imagine that there ever could be a language where 
> variables were first class values *exactly* the same as ints, strings, 
> floats etc. Otherwise, how could you tell the difference between a 
> function which operated on the variable itself, and one which operated on 
> the value contained by the value?

Its standard fare in theorem proving languages -
see eg twelf: https://www.cs.cmu.edu/~fp/papers/cade99.pdf
where the distinction is made between variables in the meta-language (ie twelf itself)
and variables in the the object theory

What you mean by *exactly* the same mean, I am not sure...

Also I note that I was not meaning first-classness of variables in C in that
literal sense.  Its just I consider them more first-class than say Pascal but 
less than say Lisp.

[The wikipedia link that Chris posted links to an article that makes the claim that
firstclassness is not really defined but can be used in a vague/relative way ]