proposal: time: add Ticker functions to affect the next tick

[justincpresley]

While it accomplishes the goal, I find the time.Ticker's API to be very limiting.
In many unique cases, you may want the functionality of a ticker but also want more control over when the next tick happens. One method to achieve this is to simply create a new Ticker. However, this becomes burdensome for the Garbage Collector if we are operating at the millisecond/nanosecond duration. It also is arguably inefficient for such a small feature especially if this is done for a larger project.

To help tackle this, I propose the following API:

// Sets the duration till the next tick happens.
// Ticker resumes the normal duration after the next tick.
(t *Ticker) Set(time.Duration)

// Skip immediately executes a tick.
(t *Ticker) Skip()

// Add adds time before the next tick happens.
(t *Ticker) Add(time.Duration)

// TimeLeft returns the duration of time till the next tick.
(t *Ticker) TimeLeft() time.Duration

[ianlancetaylor]

The point of time.Ticker is that it tries to give a regular tick regardless of system delays and such. You seem to be describing a different kind of functionality. I think you could probably build what you want on top of time.Timer. That seems like a better direction than complicating time.Ticker.

[rsc]

This proposal has been added to the active column of the proposals project
and will now be reviewed at the weekly proposal review meetings.
— rsc for the proposal review group

[rsc]

Based on the discussion above, this proposal seems like a likely decline.
— rsc for the proposal review group

[rsc]

No change in consensus, so declined.
— rsc for the proposal review group