Skip to content

Commit

Permalink
Update & expand spec text to cover fallback values and pattern selection
Browse files Browse the repository at this point in the history
  • Loading branch information
@eemeli
eemeli committed Dec 2, 2023
1 parent 5b8434a commit f928077
Showing 1 changed file with 264 additions and 20 deletions.
284 changes: 264 additions & 20 deletions spec.emu
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,11 +56,11 @@ contributors: Eemeli Aro
1. Let _matcher_ be ? GetOption(_options_, *"localeMatcher"*, ~string~,
« *"lookup"*, *"best fit"* », *"best fit"*).
1. Let _userFunctions_ be ? Get(_options_, *"functions"*).
1. Let _runtime_ be ? GetMessageRuntime(_userFunctions_).
1. Let _functions_ be ? GetMessageFunctions(_userFunctions_).
1. Set _messageFormat_.[[MessageData]] to _msgData_.
1. Set _messageFormat_.[[RequestedLocales]] to _requestedLocales_.
1. Set _messageFormat_.[[LocaleMatcher]] to _matcher_.
1. Set _messageFormat_.[[Runtime]] to _runtime_.
1. Set _messageFormat_.[[Functions]] to _functions_.
1. Return _messageFormat_.
</emu-alg>
</emu-clause>
Expand Down Expand Up @@ -90,7 +90,7 @@ contributors: Eemeli Aro

<emu-note>
Unlike other Intl formatters,
MessageFormat does not necessarily have a single list of locales that it supports,
MessageFormat does not have a single list of locales that it supports,
as it calls on other formatters as necessary.
</emu-note>
</emu-clause>
Expand Down Expand Up @@ -126,19 +126,65 @@ contributors: Eemeli Aro
</p>
</emu-clause>

<emu-clause id="sec-intl.messageformat.prototype.select">
<h1>Intl.MessageFormat.prototype.resolveMessage ( [ _values_ [ , _onError_ ] ] )</h1>
<emu-clause id="sec-intl.messageformat.prototype.format">
<h1>Intl.MessageFormat.prototype.format ( [ _values_ [ , _onError_ ] ] )</h1>

<p>
When the `resolveMessage` method is called with optional arguments
When the `format` method is called with optional arguments
_values_ and _onError_, the following steps are taken:
</p>

<emu-alg>
1. Let _mf_ be the *this* value.
1. Perform ? RequireInternalSlot(_mf_, [[InitializedMessageFormat]]).
1. ...TODO
1. Return ! ResolveMessage(_mf_, _values_, _onError_).
1. Let _msg_ be ? ResolveMessage(_mf_, _values_, _onError_).
1. Let _result_ be an empty String.
1. For each element _mv_ of _msg_, do
1. If _mv_ is a String, then
1. Let _stringValue_ be _mv_.
1. Else,
1. Let _toString_ be ? Get(_mv_, *"toString"*).
1. Let _toStringResult_ be Completion(Call(_toString_, _mv_)).
1. If _toStringResult_ is a normal completion, then
1. Let _stringValue_ be _toStringResult_.[[Value]].
1. Else,
1. Perform ? HandleMessageFormatError(_onError_, _stringResult_).
1. Let _stringValue_ be MessageFallbackString(_mv_).
1. Set _result_ to the string-concatenation of _result_ and _stringValue_.
1. Return _result_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-intl.messageformat.prototype.formatToParts">
<h1>Intl.MessageFormat.prototype.formatToParts ( [ _values_ [ , _onError_ ] ] )</h1>

<p>
When the `formatToParts` method is called with optional arguments
_values_ and _onError_, the following steps are taken:
</p>

<emu-alg>
1. Let _mf_ be the *this* value.
1. Perform ? RequireInternalSlot(_mf_, [[InitializedMessageFormat]]).
1. Let _msg_ be ? ResolveMessage(_mf_, _values_, _onError_).
1. Let _result_ be an empty List of Objects.
1. For each element _mv_ of _msg_, do
1. If _mv_ is a String, then
1. Let _textPart_ be OrdinaryObjectCreate(%Object.prototype%).
1. Perform ! CreateDataPropertyOrThrow(_textPart_, *"type"*, *"text"*).
1. Perform ! CreateDataPropertyOrThrow(_textPart_, *"value"*, _mv_).
1. Append _textPart_ to _result_.
1. Else,
1. Let _toParts_ be ? Get(_mv_, *"toParts"*).
1. Let _partResult_ be Completion(Call(_toParts_, _mv_)).
1. If _partResult_ is a normal completion, then
1. Let _parts_ be _partResult_.[[Value]].
1. For each _part_ of _parts_, append _part_ to _result_.
1. Else,
1. Perform ? HandleMessageFormatError(_onError_, _partResult_).
1. Let _fallbackPart_ be MessageFallbackPart(_mv_).
1. Append _fallbackPart_ to _result_.
1. Return CreateArrayFromList(_result_).
</emu-alg>
</emu-clause>

Expand Down Expand Up @@ -174,13 +220,17 @@ contributors: Eemeli Aro
</tr>
</thead>
<tr>
<td>[[RequestedLocales]]</td>
<td>*"locales"*</td>
<td>[[Functions]]</td>
<td>*"functions"*</td>
</tr>
<tr>
<td>[[LocaleMatcher]]</td>
<td>*"localeMatcher"*</td>
</tr>
<tr>
<td>[[RequestedLocales]]</td>
<td>*"locales"*</td>
</tr>
<tr>
<td>[[MessageData]]</td>
<td>*"message"*</td>
Expand Down Expand Up @@ -216,7 +266,7 @@ contributors: Eemeli Aro
with the canonicalized language tags of the requested locales
to use for message formatting.
</li>
<li>[[Runtime]] is an Object ...TODO</li>
<li>[[Functions]] is an Object ...TODO</li>
</ul>
</emu-clause>

Expand All @@ -232,22 +282,133 @@ contributors: Eemeli Aro
<dl class="header">
<dt>description</dt>
<dd>
It determines the message data representation corresponding to the input _source_ according to the
<a href="https://github.com/unicode-org/message-format-wg/blob/main/spec/syntax.md">
Unicode MessageFormat 2.0 syntax</a>.
<p>
It determines the message data representation corresponding to the input _source_ according to the
<a href="https://github.com/unicode-org/message-format-wg/blob/main/spec/syntax.md">Unicode MessageFormat 2.0 syntax</a>.
The message data representation is an Object conforming to the
<a href="https://github.com/unicode-org/message-format-wg/blob/main/spec/data-model/message.json">JSON Schema definition</a>
of the Unicode MessageFormat 2.0 specification.
</p>

<p>If _source_ contains a syntax or data model error, this operation throws a %SyntaxError%.</p>
</dd>
</dl>
</emu-clause>

<emu-clause id="sec-getmessageruntime" type="abstract operation">
<emu-clause id="sec-getmessagefunctions" type="abstract operation">
<h1>
GetMessageRuntime (
GetMessageFunctions (
_userFunctions_: an Object or undefined,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>...TODO</dd>
<dd>It determines the functions available during message formatting.</dd>
</dl>

<emu-alg>
1. ...TODO
</emu-alg>
</emu-clause>

<emu-clause id="sec-handlemessageformaterror" type="abstract operation">
<h1>
HandleMessageFormatError(
_onError_: a Function or undefined,
_completionRecord_: a Completion Record,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It handles errors during formatting.</dd>
</dl>

<emu-alg>
1. Assert: _completionRecord_ is a Completion Record.
1. Assert: _completionRecord_ is an abrupt completion.
1. Let _error_ be _completionRecord_.[[Value]].
1. If _onError_ is not *undefined*, then
1. Perform ? Call(_onError_, *undefined*, &laquo; _error_ &raquo;).
1. Else if an appropriate notification mechanism exists, then
1. An implementation should issue a warning for _error_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-messagefallbackpart" type="abstract operation">
<h1>
MessageFallbackPart (
_mv_: an Object
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It gets the fallback formatted part representation of a MessageValue</dd>
</dl>

<emu-alg>
1. Let _result_ be OrdinaryObjectCreate(%Object.prototype%).
1. Let _source_ be MessageValueSource(_mv_).
1. Perform ! CreateDataPropertyOrThrow(_result_, *"type"*, *"fallback"*).
1. Perform ! CreateDataPropertyOrThrow(_result_, *"source"*, _source_).
1. Return _result_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-messagefallbackstring" type="abstract operation">
<h1>
MessageFallbackString (
_mv_: an Object
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It gets the fallback formatted string representation of a MessageValue</dd>
</dl>

<emu-alg>
1. Let _source_ be MessageValueSource(_mv_).
1. Let _result_ be the string-concatenation of *"{"*, _source_, and *"}"*.
1. Return _result_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-messagevaluesource" type="abstract operation">
<h1>
MessageValueSource (
_mv_: an Object
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>
It gets the source string representation of a MessageValue,
which should be always available.
On any error, return the Unicode replacement character � instead.
</dd>
</dl>

<emu-alg>
1. Let _source_ be Completion(Get(_mv_, *"source"*)).
1. If _source_ is a normal completion, then
1. Let _str_ be _source_.[[Value]].
1. If _str_ is a String, then
1. Return _str_.
1. Return *"\uFFFD"*.
</emu-alg>
</emu-clause>

<emu-clause id="sec-resolveexpression" type="abstract operation">
<h1>
ResolveExpression (
_mf_: an Object,
_values_: an Object,
_onError_: a Function or undefined,
_expression_: an Object,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It resolves the value of an expression for selection and formatting.</dd>
</dl>

<emu-alg>
Expand All @@ -260,17 +421,100 @@ contributors: Eemeli Aro
ResolveMessage (
_mf_: an Object,
_values_: an Object,
_onError_: a Function,
_onError_: a Function or undefined,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>...TODO</dd>
<dd>It resolves a message during formatting into a List of MessageValue Objects.</dd>
</dl>

<emu-alg>
1. ...TODO
1. Let _result_ be an empty List.
1. Let _pattern_ be ? SelectPattern(_mf_, _values_, _onError_).
1. For each element _el_ of _pattern_,
1. If _el_ is a String, then
1. Append _el_ to _result_.
1. Else,
1. Let _mv_ be ResolveExpression(_mf_, _values_, _onError_, _el_).
1. Append _mv_ to _result_.
1. Return _result_.
</emu-alg>
</emu-clause>

<emu-clause id="sec-selectpattern" type="abstract operation">
<h1>
SelectPattern (
_mf_: an Object,
_values_: an Object,
_onError_: a Function or undefined,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It selects the pattern to format from the message data model.</dd>
</dl>

<emu-alg>
1. Let _msgData_ be _mf_.[[MessageData]].
1. Let _msgType_ be ? Get(_msgData_, *"type"*).
1. Assert: _msgType_ is a String.
1. If _msgType_ is *"message"*, then
1. Let _pattern_ be ? Get(_msgData_, *"pattern"*).
1. Else,
1. Let _selectorsData_ be ? Get(_msgData_, *"selectors"*).
1. Let _selectorExpressions_ be ? CreateListFromArrayLike(_selectorsData_, &laquo; Object &raquo;).
1. Let _selectors_ be an empty List of Object and Null values.
1. For each element _selExp_ of _selectorExpressions_,
1. Let _sel_ be ResolveExpression(_mf_, _values_, _onError_, _selExp_).
1. Let _selectKeys_ be ? Get(_sel_, *"selectKeys"*).
1. If IsCallable(_selectKeys_) is *true*, then
1. Append _sel_ to _selectors_.
1. Else,
1. Let _errorCompletion_ be ThrowCompletion(*TypeError*).
1. Perform ? HandleMessageFormatError(_onError_, _errorCompletion_).
1. Append *null* to _selectors_.
1. Let _variantsArray_ be ? Get(_msgData_, *"variants"*).
1. Let _variants_ be ? CreateListFromArrayLike(_variantsArray_, &laquo; Object &raquo;).
1. Let _selectedVariant_ be ? SelectVariant(_selectors_, _variants_, _onError_).
1. Let _patternBody_ be ? Get(_pattern_, *"body"*).
1. Return ? CreateListFromArrayLike(_patternBody_, &laquo; String, Object &raquo;).
</emu-alg>
</emu-clause>

<emu-clause id="sec-selectvariant" type="implementation-defined abstract operation">
<h1>
SelectVariant (
_selectors_: a List of Object and Null values,
_variants_: a List of Objects,
_onError_: a Function or undefined,
)
</h1>
<dl class="header">
<dt>description</dt>
<dd>
<p>
It applies the variant selection method defined by
the "Resolve Preferences", "Filter Variants", and "Sort Variants" steps of the
<a href="https://github.com/unicode-org/message-format-wg/blob/main/spec/formatting.md#pattern-selection">Pattern Selection</a>
section of the Unicode MessageFormat 2.0 specification.
</p>

<p>
For the selection, Null values in _selectors_ indicate selectors for which selection will always fail.
If any errors are encountered during the selection,
the HandleMessageFormatError abstract operation must be called
with _onError_ and an abrupt Completion Record containing an Error.
</p>

<p>
The value returned by this operation must be an Object matching the JSON Schema definition of a message pattern:
<a href="https://github.com/unicode-org/message-format-wg/blob/main/spec/data-model/message.json#/$defs/pattern">
https://github.com/unicode-org/message-format-wg/blob/main/spec/data-model/message.json#/$defs/pattern
</a>.
</p>
</dd>
</dl>
</emu-clause>
</emu-clause>
</emu-clause>

0 comments on commit f928077

Please sign in to comment.