Destructuring

Syntax

destructuring_expression
  = pattern ":=" expression

Example

(@ok, val) := (@ok, 42);

Semantics

A destructuring expression MUST evaluate to the matched value, allowing chaining:

# evaluates to (1, 2)
(a, 2) := (1, b) := (1, 2);
# a = 1, b = 2

If the pattern on the left does not match the expression on the right, an exception MUST be thrown. The value of this exception is defined by the implementation:

@ok := @error;
# equivalent to
throw @implementation_defined_error;