try-finally (tweet)

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The recent addition of finally-clauses to try-blocks not only gives you a powerful tool to clean up (e.g. locks) in a disciplined and structured way. It will interpose all control-flow paths outward of the try-catch and additionally also clean up if a canister traps after receiving a reply from extern. Previously this scenario could potentially brick your canister. Still, be very careful when reviewing code that does external messaging and may trap. Continue learning at https://internetcomputer.org/docs/current/motoko/main/writing-motoko/errors/#using-tryfinally.