I was wondering if it is really necessary to provide the function arguments in uni's linq example both with the right names in the inline assignmants and with the right position in the argument list. And in fact, sometimes you really can mix the order. However, this does not work always and I am not able to find an explanation, when this works and when it does not. Another issue which adds complexity is the question, which of the inline definitions is visible outside.

This provides limitless options to hide your design intent from uninitiated outsiders.

Edited by user 27 April 2014 10:37:43(UTC)  | Reason: Not specified

Maybe it's like this: first step is assigning all formal variables their symbolic values by place, then evaluate all symbolic values from left to right, executing all side-effects (possibly overwriting previously calculated params when name is reassigned):

f(x:=10; z:=20; y:=3)
=step 1=> x->x:=10; y->z:=20; z->y:=3
=step 2=> x=<result of evaluating x:=10>
=step 3=> y=<result of evaluating z:=20> - here y is 20, AND z is 20
=step 4=> z=<result of evaluating y:=3> - here z is 3, AND y is 3!

This explains all Radovan's samples, but not Martin's. Here's why.

select(`(x):=x^2;`v:=(1..4))
=step 1=> `v->`(x):=x^2; `->`v:=(1..4)
=step 2=> `v=<result of evaluating `(x):=x^2> - here TWO functions are created: `(x) AND `v(x)! - EDIT: not true. Only one function `(x)=x^2, and one variable `v=x^2.
=step 3=> `=<result of evaluating `v:=(1..4)> - here TWO vector variables are created: `v AND `! So, TWO entities names ` coexist at this time: a function and a variable.
smath allows having many entities of same name: a variable and a number of functions having different number of args (overloading).
In select, then, only vector `v and function `(x) are used.

Edited by user 27 April 2014 15:13:18(UTC)  | Reason: Not specified

Very interesting things you wrote here, guys. I want only to say what I choosed ` symbol because in this case the equation has view which is similiar to original lamdba definition: (x) => x^2. And we have `(x) := x^2. Nothing else.

EDIT: As for the local vars. In first version I used _, but I changed it to ` because this likes me more. Usually you use _x for locals, but I used `x for short.
EDIT2: (x) => ... - must be an implicit function and when we write `(x) := ... it looks like a function without name ( "implicit" ).

Edited by user 27 April 2014 15:25:09(UTC)  | Reason: Not specified

Note that function as parameter is another syntax: f(g(2)...):=... or f(g(a;b;c)...):=... where a, b and c are uninitialized at the time of definition. It's covered here.

That approach is somewhat limited, I'd say it's not ready for prime-time yet, that's why this uni's technique is required (and invaluable to workaround, say, SS-123).