Intl: ICU 55 to 56 bump

[srl295]

• This is a follow on to the ICU 54 --> 55 update build: bump ICU from 54 to 55 #2292
• Release is early Oct 2015 planned for Oct 7, 2015
• some perf improvements - full docs at http://site.icu-project.org/download/56

[srl295]

ICU 56r1 dropped today. Interested parties can test (noting #3065 which could bite you ) with:

 ./configure --with-icu-source=http://download.icu-project.org/files/icu4c/56rc/icu4c-56_rc-src.zip --with-intl=full-icu --download=all

[rvagg]

@srl295 if/when you bump to 56 in the configure could you try and give us a quick summary of improvements that can go in the changelog? Is it simply just "perf"?

[srl295]

Yes definitely. I will expand on the changes.

There's always fresh data, latest time zone changes and such. But there are
other improvements I will note. No new features.

[srl295]

Heads up - ICU 56 planned GA today. I'll be submitting a PR soon

[srl295]

Summarizing from here

• CLDR 28 5% new data, 8% corrections

Which reminds me, I will need to review the icutrim behavior - some new data categories to trim out.

• Unicode 8.0

This would affect string normalization, etc.

• ICU data size reduced by about 7.2% (1.8MB) via sharing string values across resource bundles.
• Support for locale key "cf" to specify currency format style, and interaction with NumberFormat values for UNumberFormatStyle: [doc: update to current V8 versions #11787]

I assume this will pass through to Intl but need to test. example would be locale en-us-u-cf-account for negative numbers like (4.56) instead of -4.56

• Larger UnicodeString object

More on stack, less heap. Should reduce heap usage.

• DecimalFormat code refactored to fix bugs, improve maintainability, and improve performance

14% to 72% improvements for some cases! Usual benchmark disclaimers apply!

• Collator: first-time startup time improved 20% due to precalculated unsafe-backward table

My personal contribution to this list.

• A number of memory leaks and buffer overruns have been fixed based on static code analysis, mostly in data build tools.

And of course,

• latest time zone data

[srl295]

Note that #3065 enables building full-icu, not the default small-icu. Given the timing, I'll fix the remaining 56 issues in this issue instead.

Looks like a false alarm / unclean local build dir. Clean build worked fine.

[srl295]

Looks like so far, the delta for small-icu and full-icu from ICU 55 to 56 is about 700k on linux x64. May be possible to trim further but i'd probably not (at this point) unless there's a call to.

[srl295]

perf ICU 56 makes for(var k=0;k<10000;k++) { (123.45) .toLocaleString(); } run about twice as fast as ICU 55. ..

edit and it gets better... var nf = new Intl.NumberFormat(); for (...) { nf.format(123.45); } is more like 3x faster