0.12.0

• motoko (moc)

  • feat: finally clauses for try expressions (#4507).

    A trailing finally clause to try/catch expressions facilitates structured
    resource deallocation (e.g. acquired locks, etc.) and similar cleanups in the
    presence of control-flow expressions (return, break, continue, throw).
    Additionally, in presence of finally the catch clause becomes optional and
    and any uncaught error from the try block will be propagated, after executing the finally block.

    Note: finally-expressions that are in scope will be executed even if an execution
    path following an await-expression traps. This feature, formerly not available in Motoko,
    allows programmers to implement cleanups even in the presence of traps. For trapping
    execution paths prior to any await, the replica-provided state roll-back mechanism
    ensures that no cleanup is required.

    The relevant security best practices are accessible at
    https://internetcomputer.org/docs/current/developer-docs/security/security-best-practices/inter-canister-calls#recommendation

    BREAKING CHANGE (Minor): finally is now a reserved keyword,
    programs using this identifier will break.

  • bugfix: mo-doc will now generate correct entries for public variables (#4626).