4 ms·

Making it lexical scope would make both of these solvable, and would be clear for anyone reading it. You can just introduce a new scope wherever you want with

• lowmagnet 1y ago
  You can start a new scope with `{}` in go. If I have a bunch of temp vars I'll declare the final result outside the braces and then do the work inside. But lately days I'll just write a function. It's clearer and easier to test.
• tgv 1y ago
  Currently, you can write if (some condition) { defer x() } When it's lexically scoped, you'd need to add some variable. Not that that happens a lot, but a lexically scoped defer isnt needed often either.
  • iainmerrick 1y ago
    What's an example of where you'd need to do that? I can't recall ever needing that (but that might just be because I'm used to lexical scoping for defer-type constructs / RAII).
    • tgv 1y ago
      Someone already replied, but in general when you conditionally acquire a resource, but continue on failing. E.g., if you manage to acquire it, defer the Close() call, otherwise try to get another resource. Another example I found in my code is a conditional lock. The code runs through a list of objects it might have to update (note: it is only called in one thread). As an optimization, it doesn't acquire a lock on the list until it finds an object that has to be changed. That allows other threads to use/lock that list in the meantime instead of waiting until the list scan has finished. I now realize I could have used an RWLock...
  • atombender 1y ago
    I frequently use that pattern. For example, something like this: a := Start() if thingEnabled { thing := connectToThing() defer thing.Close() a.SetThing(thing) } a.Run(ctx)
  • raluk 1y ago
    Having lexicial scope it is same as -> defer fn{if(some condition) x() }() within scope.
    • tgv 1y ago
      Except 'some condition' may change, can be long, or expensive, so you likely need an extra variable.