Document DateTime.parse accepted format.

Document DateTime.parse accepted format.

Mention in toString and toIso8601String that the output can be
put back into parse.

Change description of format to match the corresponding format letters
used by package:intl.

BUG= http://dartbug.com/21226
R=sgjesse@google.com

Committed: https://code.google.com/p/dart/source/detail?r=40919

[Lasse Reichstein Nielsen, 2014-10-06 09:24:27]

lrn@google.com changed reviewers:
+ sgjesse@google.com

[Søren Gjesse, 2014-10-06 09:29:01]

lgtm

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart
File sdk/lib/core/date_time.dart (right):

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:205: * * A date: A signed four-to-six digit year,
two digit month and
why restricted to 6?

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:210: *   then optionally  and a two digit minutes
value,
remove 'and'

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:212: *   then optionally a '.' and a one-to-six
digit second fraction.
and -> followed by

[Lasse Reichstein Nielsen, 2014-10-06 09:47:20]

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart
File sdk/lib/core/date_time.dart (right):

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:205: * * A date: A signed four-to-six digit year,
two digit month and
JavaScript has that limit, and we inherit the JS limit on valid days (+/-
1000000 days from epoch), so anything outside of 6 days is always too big.
ISO8601 allows more than 4 digits of year, but only if creator and receiver
pre-agrees on the number of digits. Out toString cannot create more than six
digits (because of the above limit on days), so this is kind of an agreement.

Actually, ISO8601 requires the >4 digit years to always have a sign, even if it
is '+'.
Noticing that, I'll change toIso8601String to always do four digit or
forced-signed six digit years

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:210: *   then optionally  and a two digit minutes
value,
On 2014/10/06 09:29:01, Søren Gjesse wrote:
> remove 'and'

Done.

https://codereview.chromium.org/629943002/diff/1/sdk/lib/core/date_time.dart#...
sdk/lib/core/date_time.dart:212: *   then optionally a '.' and a one-to-six
digit second fraction.
On 2014/10/06 09:29:01, Søren Gjesse wrote:
> and -> followed by

Done.

[Søren Gjesse, 2014-10-06 10:12:48]

lgtm

https://codereview.chromium.org/629943002/diff/60001/sdk/lib/core/date_time.dart
File sdk/lib/core/date_time.dart (right):

https://codereview.chromium.org/629943002/diff/60001/sdk/lib/core/date_time.d...
sdk/lib/core/date_time.dart:449: static String _fourDigits(int n) {
assert [-9999, 9999] here (like in the six digit case)?

[Lasse Reichstein Nielsen, 2014-10-06 10:13:41]

https://codereview.chromium.org/629943002/diff/60001/sdk/lib/core/date_time.dart
File sdk/lib/core/date_time.dart (right):

https://codereview.chromium.org/629943002/diff/60001/sdk/lib/core/date_time.d...
sdk/lib/core/date_time.dart:449: static String _fourDigits(int n) {
Can't, we are using it from the plain toString too, which may call with
|year|>9999.

[Lasse Reichstein Nielsen, 2014-10-06 10:14:01]

Committed patchset #4 (id:60001) manually as 40919 (presubmit successful).