go2-error-handling-proposal.md

go2-error-handling-proposal

I propose try-return statements.

Syntax

"try" IdentifierList ( ":=" | "=" ) ExpressionList "return" ExpressionList

e.g. try a, err := foo() return err

1. Perform variable declarations or assignments.
2. If the value of the rightmost variable is zero-valued, evaluate the second ExpressionList and return.

Examples

Transparent Error

// Conventional
a, b, err := foo()
if err != nil {
    return err
}

// Proposed
try a, b, err := foo() return err

New (or Wrapped) Error

try a, b, err := foo() return errors.New("A new error")

Custom Error Handler

myErrorHandler := func(err error) error {
    doSomething()
    return err
}

try a, b, err := foo() return myErrorHandler(err)