proposal: Go 2:

[dmitryuck]

Author background

• Would you consider yourself a novice, intermediate, or experienced Go programmer?
• I'm a novice
• What other languages do you have experience with?
• Js

Related proposals

• Has this idea, or one like it, been proposed before?
• Not sure
  • If so, how does this proposal differ?
• Does this affect error handling?
• Yes
  • If so, how does this differ from previous error handling proposals?
• Is this about generics?
• No
  • If so, how does this relate to the accepted design and other generics proposals?

Proposal

• What is the proposed change?
• Add a new way of error handling
• Who does this proposal help, and why?
• This adds a new convenient way of handling errors
• Please describe as precisely as possible the change to the language.
  the error handles after the function call, block executes when error != nil

func MyFunc(arg1, arg2 any) error {
  // Function body

  return errors.New("Some error info")
}

in a place where we call this function

err := MyFunc(arg1, arg2) {
  // An error handling goes here
  Log(err)
}

similar to function with return value

  func MyFunc(arg1, arg2 any) any error {
    // Function body

    return nil errors.New("Some error info")
  }

  in a place where we call this function

  result, err := MyFunc(arg1, arg2) {
    // An error handling goes here
    Log(err)
  }

• What would change in the language spec?
• Adding a specific error handling mechanism: A curly braces after a function call
• Please also describe the change informally, as in a class teaching Go.
• Add a mechanism to handle any error in function like callback after a function call
• Is this change backward compatible?
• yes, compatible with G1
  • Breaking the Go 1 compatibility guarantee is a large cost and requires a large benefit.
    Show example code before and after the change.
  • Before
  • After
• Orthogonality: how does this change interact or overlap with existing features?
• No conflicts with existing code
• Is the goal of this change a performance improvement?
• No, more about convenience and elegance
  • If so, what quantifiable improvement should we expect?
  • How would we measure it?

Costs

• Would this change make Go easier or harder to learn, and why?
• No effect
• What is the cost of this proposal? (Every language change has a cost).
• Don't know
• How many tools (such as vet, gopls, gofmt, goimports, etc.) would be affected?
• None
• What is the compile time cost?

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• What is the run time cost?

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• Can you describe a possible implementation?

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• Do you have a prototype? (This is not required.)

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[seankhliao]

Duplicate of #41908