Named results in Go

Naming the results lets a deferred function edit them on the way out.

func withTiming(work func() error) (elapsed time.Duration, err error) {
    started := time.Now()
    defer func() {
        elapsed = time.Since(started)
        if err != nil {
            err = fmt.Errorf("after %s: %w", elapsed.Round(time.Millisecond),
                err)
        }
    }()

    err = work()
    return
}

How it works

1. The names document what comes back.
2. A bare return sends the current values.
3. Use them for the defer trick, not to save typing.

Keywords and builtins used here

• defer
• error
• func
• if
• return

The run, in numbers

Lines

13

Characters to type

254

Tokens

74

Three-star pace

105 tpm

At the three-star pace of 105 tokens a minute, this run takes about 42 seconds.

Type this snippet

Step 4 of 4 in defer, panic & recover, step 13 of 15 in Errors.

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