Add Kind/StringID/IntID back to Key.

Add Kind/StringID/IntID back to Key.

Rename Last -> LastTok.

luci-go change here: https://chromiumcodereview.appspot.com/1359813004

R=dnj@chromium.org, estaab@chromium.org, maruel@chromium.org, tandrii@chromium.org, vadimsh@chromium.org
BUG=

Committed: https://github.com/luci/gae/commit/84d674199367bc12a173d8b9a3483345dc942fdc

[dnj, 2015-09-22 17:56:19]

lgtm w/ nit

https://codereview.chromium.org/1358063003/diff/1/service/datastore/key.go
File service/datastore/key.go (right):

https://codereview.chromium.org/1358063003/diff/1/service/datastore/key.go#ne...
service/datastore/key.go:192: func (k *Key) Kind() string { return
k.toks[len(k.toks)-1].Kind }
nit: Use "LastTok" here (and in StringID and IntID).

[Vadim Sh., 2015-09-22 17:57:14]

lgtm

though I'd prefer "LastPair()" instead of "LastTok()". But you use Tok to
identify (kind, id) pair in other code too, so whatever.

[iannucci, 2015-09-22 18:12:47]

On 2015/09/22 at 17:57:14, vadimsh wrote:
> lgtm
> 
> though I'd prefer "LastPair()" instead of "LastTok()". But you use Tok to
identify (kind, id) pair in other code too, so whatever.

It's actually a triple (sorta...). If only go had algebraic datatypes, then we
could have `(string, string-or-int64)`

[iannucci, 2015-09-22 18:12:50]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2015-09-22 18:13:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1358063003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1358063003/1

[commit-bot: I haz the power, 2015-09-22 18:14:53]

Committed patchset #1 (id:1) as
https://github.com/luci/gae/commit/84d674199367bc12a173d8b9a3483345dc942fdc

[iannucci, 2015-09-23 23:51:48]

oh, forgot to publish >_<

https://codereview.chromium.org/1358063003/diff/1/service/datastore/key.go
File service/datastore/key.go (right):

https://codereview.chromium.org/1358063003/diff/1/service/datastore/key.go#ne...
service/datastore/key.go:192: func (k *Key) Kind() string { return
k.toks[len(k.toks)-1].Kind }
On 2015/09/22 at 17:56:19, dnj wrote:
> nit: Use "LastTok" here (and in StringID and IntID).

nah, it creates an extra copy I don't want.