* Accept attributes design & remove spec note

* Disallow duplicate attribute names (closes #756)

* Add link to contextual options PR

* Add more prose to tag example text

Co-authored-by: Addison Phillips <addison@unicode.org>

* Mention attribute validity condition in the **_valid_** definition

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

…on (#867)

* Add tests for pattern selection

* Add missing errors

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

…ctor variables in placeholders (#860)

* Add new selection-declaration alternative: Require annotation of selector variables in placeholders

* Improve examples

* Switch example order

* Update the stability policy

Based on discussion in the 2024-07-22 call and in PR #829, update the stability policy.

* A deeper, more thorough rewrite

- Standardizes the phrasing completely.
- Moves all potential future changes (which are not, after all, stability policies) to an "important" block
- Removes duplication
- Separates functions, options, and option values into separate guarantees
- Clarifies the note about formatting changing over time

* Update spec/README.md

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Update spec/README.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* remove well-formed

* Update spec/README.md

---------

Co-authored-by: Tim Chevalier <tjc@igalia.com>
Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Refine error handling text

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Update fallback text

* Turn bullet point list into paragraphs

* Be more mighty

Co-authored-by: Addison Phillips <addison@unicode.org>

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

…arations (#824)

* Select "Match on variables instead of expressions" for selection-declarations

* Add hybrid option to selection-declaration.md (#870)

* Add hybrid option to selection-declaration.md

* Update selection-declaration.md

fixed glitch in original edit

* Update selection-declaration.md

* Apply suggestions from code review

Fixing typos

Co-authored-by: Addison Phillips <addison@unicode.org>

* Update selection-declaration.md

* Update exploration/selection-declaration.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update exploration/selection-declaration.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update exploration/selection-declaration.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

---------

Co-authored-by: Addison Phillips <addison@unicode.org>
Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update selection-declaration.md

---------

Co-authored-by: Mark Davis <mark@unicode.org>
Co-authored-by: Addison Phillips <addison@unicode.org>

* Update README.md

* Update README.md

* [DESIGN] Update bidi design document to show proposed design

The design I actually think we should adopt is the "hybrid approaches" one. This is a necessary first step on the highway to UAX31 compliance and I think is responsibly contained/managed. It is a hybrid approach, in that it permits testable strict implementations to be created (particularly for message serialization).

This PR consists of moving text around. I added one "pro" to one option also.

* Address comments

* Add missing expected bad-selector errors

* Fix expected parts for unsupported-statement test

* Add a few new tests for leading-whitespace and duplicate-variant

* Add tests for escaped-char changes made in #743

* Fix tests for attributes with variable values

* Update contributing and joining info

* Update README.md

* Update CONTRIBUTING.md

* Restore CLA copy

* Clarify error & fallback handling

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Select last rather than first attribute

* Drop mention of "starting with Pattern Selection"

* Attributes can't change the formatted output

* Use "nor" instead of "or" regarding attribute restrictions

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

* Clarify rule selection

Fixes #868 

This adds normative SHOULD language to using CLDR plural and ordinal data, which was intended originally.

- clarifies that keyword selection follows exact match
- clarifies the purpose of rule-based selection
- makes non-CLDR-based implementation permitted

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

---------

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

…ction Sets (#634)

* Design doc to capture registry maintenance

* Update maintaining-registry.md

* Update exploration/maintaining-registry.md

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Update exploration/maintaining-registry.md

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Add user stories, small updates to RGI

* Update exploration/maintaining-registry.md

* Adding additional detail

* Remove machine readable registry; update prose

* Update maintaining-registry.md

* Further development work

* Update to change format and naming

Per the 2024-08-19 call, we decided to switch towards a specification-per-function model, with statuses. This commit includes the initial set of changes to try and implement this.

* Address some comments.

---------

Co-authored-by: Tim Chevalier <tjc@igalia.com>

The upcoming work to implement resolved value might make this patch unnecessary or obsolete, but fixing the typo (missing `{`/`}` around the variable in the pattern) just in case

#883)

* Remove forwards compatibility from stability guarantee

* Drop reserved statements and expressions

* Drop private-use annotations

* Update tests

* Clarify that deprecation is not removal

* Match on variables instead of expressions

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Apply suggestions from code review

* Add missing test changes noticed during implementation

* Empty commit to re-trigger CLA check

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

* Add bidi support and address UAX31/UTS55 requirements

Adds the bidi strong marks ALM, RLM, and LRM plus the bidi isolate controls LRI, RLI, FSI, and PDI to the syntax.

Formally defines optional vs. non-optional whitespace.

Non-optional whitespace must include at least one whitespace character. Optional whitespace may contain only bidi marks (which are invisible)

* Update syntax.md including text from previous PR

* Repair the guidance on strongly directional marks

Include ALM and better specify how to use the marks.

* Fix formatting of the "important"

* Add bidi characters to description of whitespace.

* Permit bidi in a few more places

Add optional whitespace at the start of `variant`

Add optional whitespace around `quoted-pattern`

These changes result in allowing bidi around keys and quoted patterns as intended.

* Update syntax.md ABNF

* Update formatting.md

- Add a note about the difference between formatting and message syntax.
- Clarify the sentence about message directionality.

* Address comment about name/identifier

* Address comments related to bidi in `name`

* Fix variable's location

* Address comment about the list of LRI/PDI targets

* One character typo :-P

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Address comments about rule R3a-1

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Address comment about U+061C

* Change [o]wsp => `o` or `s`

* Match syntax spec to abnf

* Remove *

* Update syntax.md

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/message.abnf

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/message.abnf

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update syntax.md

* Update spec/message.abnf

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

---------

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Specify `bad-option` for bad digit size option values

Fixes #739

* adopt 'non-negative integer'

* Address name and literal equality

This change defines equality as discussed in the 2024-09-09 teleconference in the following ways:

- It defines _name_ equality as being under NFC
- It defines _literal_ equality as explicitly **not** under NFC
- It moves _name_ before _identifier_ in that section of text to avoid a forward definition.

Note that this deviates from discussion in 2024-09-09's call in that we didn't discuss literals at length. It also doesn't discuss non-name/non-literal values, which I'll point out are limited to ASCII sequences such as keywords.

* Typo fix

* Add a note about not requiring implementations to actually normalize

* Implement changes dicussed in 2024-09-16 call.

- Make _key_ require NFC for uniqueness/comparison
- Add a note about NFC
- Make _literal_ **_not_** define equality
- Make text in _name_ identical to that in _key_ for consistency

* Update formatting.md to include keys in NFC

* Address comments

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/syntax.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

---------

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

Fix #886

Addresses #887 

Non-normative changes to the notes specifically part of LDML46

Fixes #893

* Add Resolved Values section to formatting

* Apply suggestions from code review

* Apply suggestions from code review

* Apply suggestions from code review

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Linkify "resolved value"

* Add some examples & explicitly allow wrapping input values

* No throw, only emit

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Add section on Function Handlers, defining the term

* Apply suggestions from code review

* Rephrase initial resolved value definition

* Update spec/formatting.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update resolved value definition again

Co-authored-by: Addison Phillips <addison@unicode.org>

---------

Co-authored-by: Tim Chevalier <tjc@igalia.com>
Co-authored-by: Addison Phillips <addison@unicode.org>

* Define function composition for :number and :integer values

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Add operand option priority example

* Add apostrophes'

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

---------

Co-authored-by: Addison Phillips <addison@unicode.org>
Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Apply NFC normalization during :string key comparison

* Add link to UAX#15

Co-authored-by: Addison Phillips <addison@unicode.org>

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

* Add tests for changes due to bidi/whitespace

* Correct output

* Make erroneous test a syntax error

* Define function composition for date/time values

* Apply suggestions from code review

Co-authored-by: Stanisław Małolepszy <sta@malolepszy.org>

* Drop the "only"

* Update spec/registry.md

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Update spec/registry.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Make :date and :time composition implementation-defined

---------

Co-authored-by: Stanisław Małolepszy <sta@malolepszy.org>
Co-authored-by: Addison Phillips <addison@unicode.org>

…tion (#806)

* DESIGN: Add a sequel to the design doc on function composition

This document sketches out some alternatives for the machinery
provided to enable function composition.

The goal is to provide an exhaustive list of alternatives.

* Remove 'part 2' document and move contents to the end of part 1

* Revise introduction to reflect the changed goal

* Edited for conciseness

* Further edits for conciseness

* Give a name to InputType and use it

* Refer to motivating examples

Per 2024-10-14 telecon

I noticed that `:integer` does not include the "never" value for the option `useGrouping`. This is a bug.

Drop syntax note on addition bidi changes

* Add tests for changes due to #885 (name/literal equality)

* Update test/tests/functions/string.json

Co-authored-by: Eemeli Aro <eemeli@gmail.com>

* Update test/tests/syntax.json

Co-authored-by: Eemeli Aro <eemeli@gmail.com>

* Update test/tests/functions/string.json

Co-authored-by: Eemeli Aro <eemeli@gmail.com>

* Added tests for reordering and special case mapping

* Add another selection test

---------

Co-authored-by: Eemeli Aro <eemeli@gmail.com>

* Move spec/registry.md -> spec/registry/default.md

* Add Unicode Registry definition

* Refer to BCP47, add note about only requiring normal tags

* Call it a namespace

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Fix test file reference

Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Apply suggestions from code review

* Update spec/u-namespace.md

Co-authored-by: Eemeli Aro <eemeli@mozilla.com>

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Apply suggestions from code review

Co-authored-by: Addison Phillips <addison@unicode.org>

* Add mention of functions to namespace description

---------

Co-authored-by: Addison Phillips <addison@unicode.org>
Co-authored-by: Tim Chevalier <tjc@igalia.com>

* Define function composition for :string values

* Update spec/registry.md as suggested by @stasm in #814

* Drop the "only"

* Update text following code review comments

---------

Co-authored-by: Addison Phillips <addison@unicode.org>

* Allow surrogates in content, issue #895

* Grammar and typos, linkify terms, make into a note, and fix 2119 keywords

Thanks Addison!

Co-authored-by: Addison Phillips <addisonI18N@gmail.com>

* Not using "localizable elements"

Co-authored-by: Addison Phillips <addisonI18N@gmail.com>

* Keep syntax.md in sync with message.abnf

* Added note about surrogates to quoted literals

* Moved the note about surrogates from Security Considerations to The Message

* Update spec/syntax.md

* Update spec/syntax.md

* Italicize  in a couple of places

* Implemeted more (all?) feedback from review

---------

Co-authored-by: Addison Phillips <addisonI18N@gmail.com>