keyword
function
function name(a: T, b: T) -> R { … }
A function declares a function: a reusable block of logic with typed parameters and a return type, written -> R (use -> void for one that returns nothing). Call it positionally, heal(2, 10), or with named arguments, heal(amount: 2, maximum: 10), which reads more clearly at the call site and is the house style. Functions live at program scope alongside handlers and may be called from any handler; they can spawn, run queries, and read program-scope state. Use them to factor out logic shared by several handlers so each handler stays short.
Example
program Healer {
property Health { current: int = 100, maximum: int = 100 }
model Player { Health }
function heal(amount: int, maximum: int) -> int {
let restored = amount * 2
if restored > maximum { return maximum }
return restored
}
handler Boot phase Start {
spawn Hero { Health { current: 10, maximum: 100 } }
}
handler Recover phase Update {
for (health) in query [Health, {Player}] {
health.current = heal(amount: health.current, maximum: health.maximum)
}
}
}