New version of loop

In 8th I see this construct:

Function n times

Which is the same as Rebol's

Loop n [ ... ]

But doesn't this look less busy?

Times n :function

Loop could be changed to look to see if its parameter is a function to do this automatically, but currently it's a native and not in user space.

Modulo a small bug I just fixed (and test added), LOOP does do this:

>> foo: does [print "Hi"]
== make action! [[] [...]]

>> loop 3 :foo

Also, (the recent change to the loop protocol made more looping constructs accept action!s). It has been intended that any "branch" slot which would accept a block would also accept an action!, just a matter of doing it.

That's kinda cool. I guess I missed the announce.

The more interesting feature of branches as functions is when they get an argument. ALSO, which runs whenever its left hand side is not null, will pass any arity-1 function what it got:

>> case [
       1 > 2 [10]
       1 < 2 [20]
   ] also :print

You can create functions on the spot with lambda (infix form, =>)

>> case [
       1 > 2 [10]
       1 < 2 [20]
   ] also val => [
       print ["A branch in the case ran and gave" val]
A branch in the case ran and gave 20

This is supposed to be systemic. So IF itself works this way.

>> data: [a 10 b 20]
>> if try select data 'b 
       val => [print ["If selected a value and it was" val]]
If selected a value and it was 20

Note that infix lambda is variadic, and knows a few tricks:

>> plus-one: (x => x + 1)
>> plus-one 10
== 11

>> no-arg: (=> print "woo")
>> no-arg

I think the leaning for lambdas is DOES...will not have a RETURN/LEAVE of their own. So if you say RETURN inside the body of a lambda, you use whatever RETURN was already in effect.

I had a weird idea that you would do multi-arg lambdas with paths:

>> sum2: (a/b => a + b)
>> sum2 10 20
== 30

Saves a little typing...and maybe a little visually tighter than ([a b] => a + b). Cool, or too weird?