Control Flow

Hank provides a unified flow-control system based on three sigils: ? (If), : (Fallback), and ~ (Rescue).

Unified Gates

The ?, :, and ~ sigils form a single control chain.

() {
  user_score = 95
  
  ? math_gt(user_score, 90) {
    log_print("Grade: A")
  } : {
    log_print("Grade: B")
  }
}

Optional Parentheses

Since Hank evaluates truthiness directly from expressions, parentheses around the condition are optional.

// Paren-less (Idiomatic)
? math_eq(x, y) { ... }

// Parentheses (Valid Grouped Expression)
? (math_eq(x, y)) { ... }

Rescue Gate (~)

The Rescue gate allows you to catch Runtime Exceptions (such as Type Mismatches or missing functions) without halting the script.

() {
  ? result = risky_task() {
    log_print("Task succeeded")
  } ~ (e) {
    log_error(str_format("Task failed with code: %1", err_code(e)))
  }
}

If you don't need to inspect the error, the capture variable is optional:

? risky_task() { } ~ {
  log_print("Swallowed the error")
}

## Truthiness in Hank

Hank follows a simple "Existence-is-Truth" model:
* **Truthy**: Any concrete value (Number, String, Array, Map, Opaque, Task, Error).
* **Falsy**: Only `Void` (the absence of a value).

This means `0`, `""`, and `[]` are all **Truthy**. 

```hank
? 0 { log_print("Zero is truthy") }
? [] { log_print("Empty array is truthy") }
? _ { } : { log_print("Unbound identifier is falsy (Void)") }