Overview of Labels and GOTO¶

Labeled loops¶

LOOP :outer VALUE(i) FROM(0 AS I32) TO(4) DO
{
  LOOP :inner WHILE (condition) DO
  {
    CONTINUE :outer;
  }
  BREAK :outer;
};

BREAK and CONTINUE accept an optional :label. An unlabeled statement targets its nearest valid enclosing construct.

Labeled blocks¶

LABEL :done
{
  BREAK :done;
}

A labeled block is breakable even though it is not a loop.

`GOTO`¶

GOTO :retry;
LABEL :retry;

LABEL :name; declares a statement target. GOTO :name; transfers control to it within the function.

Object lifetime remains authoritative: a jump cannot enter a scope past a required construction, bypass an initialization whose lifetime would become active, or otherwise create an impossible lifetime state. Leaving scopes runs the destruction required by the language's lifetime rules.

Reference¶

See the Labels and GOTO Reference for the complete language rules, constraints, and technical edge cases.