Function Types

Flow-Wing lets you pass functions as arguments using function type syntax.

Syntax

[(param_types) -> return_type]

Basic Callback

fun greet(name: str) -> nthg {
  print("Hello, " + name)
}

fun runCallback(cb: [(str) -> nthg]) -> nthg {
  cb("World")
}

runCallback(greet)

Output: Hello, World

Multi-Parameter Callbacks

fun add(x: int, y: int) -> int {
  return x + y
}

fun apply(op: [(int, int) -> int], a: int, b: int) -> int {
  return op(a, b)
}

var result: int = apply(add, 3, 4)
print(result)

Output: 7

Limitations

Flow-Wing does not currently support anonymous functions (lambdas/closures). Functions must be declared with fun before being passed as callbacks.