List formatting API

[zbraniecki]

A common scenario is to have a list of items (Array in JS) which has to be formatted in a given language. CLDR provides all the patterns for that.

Example use cases:

• List of participants in a chat
• List of days for which an alarm is set
• List of affected events in Calendar app

Proposed API:

var f = new Intl.ListFormat(navigator.languages, {
  'type': 'regular', // regular or duration
  'variant': 'regular', // regular, short, narrow
});

f.format(['John', 'Amy', 'Nick']); // "John, Amy and Nick" in en-US

this would also supersede current Array.prototype.toLocaleString with ability to build better localized lists.

I can imagine this not having it's own object and only extending Array.prototype.toLocaleString with options.

[zbraniecki]

Relevant CLDR entry example: http://www.unicode.org/cldr/charts/27/summary/pl.html#6947

[srl295]

Doesn't Array.prototype.toLocaleString have a different definition? Should that have a type associated with it ( maybe simple or separator, could propose it up to CLDR - as in John,Amy,Nick )

Proposal seems reasonable. I would prefer it was on Intl as well as the extension otherwise there's no object to inspect.

CLDR: Part 2 section 11

[ Also I think it's probably a good idea to link to the CLDR spec instead of just charts or data- The reason I say this is that the data can be mis interpreted without the context of the spec. Feel free to ping me if I can help locating something, and/or join cldr-users ]

[zbraniecki]

Doesn't Array.prototype.toLocaleString have a different definition?

The only thing I could find in Ecma 402 13.4.1 and Ecma 262 22.1.3.26 is that it uses toLocaleString on its members and concatenates them using locale specific separator key.

Should that have a type associated with it ( maybe simple or separator, could propose it up to CLDR - as in John,Amy,Nick )

I like it.

Proposal seems reasonable. I would prefer it was on Intl as well as the extension otherwise there's no object to inspect.

Good point.

Also I think it's probably a good idea to link to the CLDR spec instead of just charts or data

I'm getting better at navigating CLDR docs. Better doesn't mean good yet, but I'll do better, thanks! :)

[srl295]

FYI: [http://unicode.org/cldr/trac/ticket/8314](CLDR 8314) discussing <list>;</list> which is explicitly to be used in the context of a list of numbers.

[zbraniecki]

Updated proposal API:

var f = new Intl.ListFormat(locales, {
  'style': 'regular', // regular, duration, duration-short, duration-narrow, number
});

f.format(['John', 'Amy', 'Nick']); // "John, Amy and Nick" in en-US

Array.prototype.toLocaleString(locales, {
  'style': 'regular', // regular, duration, duration-short, duration-narrow, number
});

This API could also be used internally by UnitFormat, similarly to how ICU uses it in MeasureFormat - http://www.icu-project.org/apiref/icu4j/com/ibm/icu/text/MeasureFormat.html#formatMeasures%28com.ibm.icu.util.Measure...%29

[zbraniecki]

Here's a polyfill: https://github.com/zbraniecki/IntlListFormat

[caridy]

This is looking great. Let's start working on the spec on https://github.com/zbraniecki/intl-list-format-spec, btw, there is a typo in the link from the polyfill to the spec.

[zbraniecki]

Thanks, fixed the link. I didn't finish the spec yet, I'll try to do this this week.

[zbraniecki]

Added more to the spec and added type: unit per #32 (comment)

[zbraniecki]

As for elements formatting, we will use toLocaleString of the element (instead of toString).

[zbraniecki]

Heads up, this has been advanced to Stage 0 as of today.

[zbraniecki]

@srl295 and I brought to cldr-users the topic of regular/duration lists vs. number/unit lists - http://unicode.org/pipermail/cldr-users/2016-March/000469.html

Once this is resolved I'll provide the spec (I have the polyfill working) - https://github.com/l20n/mozintl/blob/master/src/formatters/list.js

[zbraniecki]

This proposal has been advanced to Stage 1 as of today.

[zbraniecki]

CLDR issue for types of lists: http://unicode.org/cldr/trac/ticket/9361

[zbraniecki]

We plan to request stage 2 at the next TC39 meeting.

[zbraniecki]

The proposal has reached stage 2 as of today.

[zbraniecki]

The proposal has reached stage 3 as of today!

[zbraniecki]

I plan to offer https://github.com/tc39/proposal-intl-list-format for Stage 4 advancement at ECMA402 call this week.

[zbraniecki]

Intl.ListFormat has been approved for Stage 4 at today's TC39 meeting!