Functions are values

There’s no special syntax for declaring a function in Ascent — no function, no def, no fn name(...). A function is a value, and you bind it with fix like anything else:

fix double = fn(x: Int): Int => x * 2;
double(5)

fn(x: Int): Int is the signature — the parameters, then the return type after a colon. The body comes in two shapes. For a single expression, => expr says “the result is this” (that’s the => x * 2 above).

For more than one line, use a block — its last expression is the value it hands back, so there’s still no return to write:

fix describe = fn(n: Int): String {
  fix doubled = n * 2;
  "twice ${n} is ${doubled}"
};
describe(7)

Same function either way: => e is just shorthand for a block { e }.