Traps and Commit Points - throw confusion

Developers
8

Exactly! Maybe this summarizes the intention of a canister well:

  • Trap (via assert false, or soon Debug.trap): “I am completely lost, better be safe and don’t record any state changes”. Same as division by 0 for example.
  • Rejecting (via throw): “The call cannot be performed, likely because the caller did something stupid, but I am still pretty sure that my state is in good order, so it can be committed”. Also “Call failed, but I maybe want to record the fact that this caller tried something”.
  • Replying, with null or #error "messages": “The caller did everything right, I am also still healthy, and and as part of the expected way of things I am returning some kind of negative result (e.g. key not present in a key value store)”.
  • Replying, with data: “All well, here you go, have a good day”.
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