Bukkit

Foreach is a handy function provided by the svefile library. Foreach uses the maybe most powerful feature of the sve language: anonymous functions.

Using foreach is easy. Give it an array and an anonymous function and – tah dah – it works.

foreach(array)::def (element) { code }

Example: send a message to all players:

foreach(@a)::def(player) { player->tell("Hi!") }

How does it work?

It can be hard to understand how foreach works. Here is it's source code:

def: foreach (t, u)
	if: !u return def (u)
		foreach(t, u)
	
	else: {
		local l = len(t)
		for:	local i=0,
			i < l,
			i++
		
			u(t[i]) }

The type of the foreach function the type notation is table(T) -> ((T -> ()) -> ()). In other words, it takes and array and returns a function, which takes an anonymous function which takes an element of the array. The returned function calls foreach again with two arguments, the second is the callback function.

Foreach can be called with two arguments and that's a perfectly valid way. But the implementation provides us a more powerfui version, a one that generates functions which perform the operation. This can be used to easily create derivate functions, below are few examples:

# iterate thru range
def: iteraterange(start, stop) = foreach(range(start, stop))

# for all players
def: forall(f) foreach(@a)::f

forall::def (p) {
    p->tell("hey!")
}