add BuildName helper func

[vtolstov]

Signed-off-by: Vasiliy Tolstov v.tolstov@unistack.org

[vtolstov]

@valyala @tenmozes can you merge this if it's ok now?

[vtolstov]

gentle ping..

[valyala]

Please see #25 (comment)

[hagen1778]

Hi @vtolstov! What would be the typical use case for the new helper?
If it is:

metrics.NewSummary(metrics.BuildName("my_metric", "zerolabel", "value3", ",firstlabel", "value2"))

then metric name validation happens twice.

If it is:

myMetricName := metrics.BuildName("my_metric", "zerolabel", "value3", ",firstlabel", "value2")
myMetric := metrics.NewSummary(myMetricName)

then it is unclear why metrics.BuildName panics instead of returning an error for processing.

IMHO, in the role of helper I'd prefer smthng like the following:

metrics.NewSummaryWithLabels("my_metric", "zerolabel", "value3", ",firstlabel", "value2")

or

metrics.NewSummary("my_metric").WithLabels("zerolabel", "value3", ",firstlabel", "value2")

wdyt?

// disclaimer: i do not maintain this repo, just out of my curiosity

[vtolstov]

@hagen1778 may be you case is better, but for now i'm move helper to own framework =)