Re: [stack] are concatenative languages applicative?

On Apr 24, 2008, at 10:35 PM, John Cowan wrote:

> John Nowak scripsit:
>
>> - '1 2 3' is a *function* of type 'A -> A Num Num Num'; when
>> evaluated, the *values* 1, 2, and 3 get pushed onto the stack
>
> I agree with that.
>
>> - '3' is a *function* of type 'A -> A Num', not a value of type 'Num'
>> as in Haskell or ML; when evaluated, the *value* 3 gets pushed onto
>> the stack [...]
>
> You are making a distinction between '3' and 3 that I believe to be
> unwarranted.  There is only 3, and it is both a numeric value and
> a function to be applied to the stack.

Maybe I'm not being precise enough. The type of the term '3' is 'A ->  
A Num', just like the type of '1 2 3' is 'A -> A Num Num Num'.

>> In short, even '3' is a function in Joy. This should be obvious as we
>> can assign a name to it:
>>
>>    foo = 3
>>
>> Here, we're not binding 'foo' to the value of 3; we're declaring that
>> 'foo' is a function that pushes '3' onto the stack.
>
> We are doing both at once.

No we're not; we don't evaluate the right-hand side to figure out what  
to bind 'foo' too.

>> Never at any point are we manipulating values.
>
> The function +, among many others, can only be understood in terms  
> of values.

Sure, but when we're manipulating programs, such as translating '1 [2  
+] i' to '1 2 +', we're not manipulating any terms bound to values.

- John