Exceptions¶

raise, try, except, and finally work exactly as they do in Python, narrowed to the other kind of failure Results doesn't cover: a broken invariant, a bug, something that should never happen — Rust's panic!, not Rust's Result. They are not for everyday, expected outcomes the way Python's StopIteration-driven iteration or its KeyError-then-catch idiom use them.

try:
    validate(config)
except ConfigError:
    log.error("invalid config, aborting")
    raise
finally:
    connection.close()

raise stays unchecked — not declared in a function's signature, not enforced by the checker. That is deliberate, not an oversight: the visibility Java wanted from checked exceptions is already delivered by recoverable errors being ordinary return types. Checking the broken- invariant case too would just be ceremony around something no caller is meant to routinely handle in the first place.