Plurals and Genders

pkg/intl/lib/intl.dart

Index: pkg/intl/lib/intl.dart
diff --git a/pkg/intl/lib/intl.dart b/pkg/intl/lib/intl.dart
index e0e32eeb977a9e10810d80e7804542d2f5cc03a8..3db37455c39186ca27eb441bfa76039fa276b260 100644
--- a/pkg/intl/lib/intl.dart
+++ b/pkg/intl/lib/intl.dart
@@ -71,7 +71,7 @@ part 'number_format.dart';
  *           '''I see ${Intl.plural(num_people,
  *             {'0': 'no one at all',
  *              '1': 'one other person',
- *              'other': '$num_people other people'})} in $place.'''',
+ *              'other': '$num_people other people'})} in $place.''',
  *          name: 'msg',
  *          args: [num_people, place],
  *          desc: 'Description of how many people are seen as program start.',
@@ -238,12 +238,42 @@ class Intl {
   }
 
   /**
-   * Support method for message formatting. Select the correct plural form from
-   * [cases] given [howMany].
+   * Format a message differently depending on [howMany]. Normally used
+   * as part of an Intl.message message that is to be translated.

[Emily Fortuna, 2013/07/03 17:52:33]

`Intl.message` 
also you probably can do without the second "message" in that sentence....

[Alan Knight, 2013/07/03 18:41:07]

Done. Changed second "message" to "text"

+   * Selects the correct plural form from
+   * the provided alternatives. The [other] named argument is mandatory.
    */
-  static String plural(var howMany, Map cases, [num offset=0]) {
-    // TODO(efortuna): Deal with "few" and "many" cases, offset, and others!
-    return select(howMany.toString(), cases);
+  static String plural(int howMany, {zero, one, two, few, many, other}) {
+    if (other == null) {
+      throw new ArgumentError("The 'other' named argument must be provided");

[Emily Fortuna, 2013/07/03 17:52:33]

in which case should we make it a positional required argument?

[Alan Knight, 2013/07/03 18:41:07]

That would mean you'd have to write it first, which seems awkward. Also, since
these names correspond to the known ICU names, it seems nice to have them all be
there and named consistently to match. In different locales, different other
forms will also be mandatory, so we can't use this as a way to be sure all the
required forms are provided.

+    }
+    // TODO(alanknight): This algorithm needs to be locale-dependent.

[Emily Fortuna, 2013/07/03 17:52:33]

how will we be able to change this behavior based on locale?

[Alan Knight, 2013/07/03 18:41:07]

I was thinking that there would be a generated implementation included with the
generated message libraries for each locale, and that this would either delegate
to that, or possibly that the translated messages would directly call the
version specific to their locale. e.g. the translation might be 
   Intl.message("${localPlural(...)}");
rather than
   Intl.message("${Intl.plural(...)}");
where localPlural is defined in each generated library.

+    switch (howMany) {
+      case 0 : return (zero == null) ? other : zero;
+      case 1 : return (one == null) ? other : one;
+      case 2: return (two == null) ? ((few == null) ? other : few) : two;
+      default:
+        if (howMany == 3 || howMany == 4 && few != null) return few;
+        if (howMany > 10 && howMany < 100 && many != null) return many;
+        return other;
+    }
+    throw new ArgumentError("Invalid plural usage for $howMany");
+  }
+
+  /**
+   * Format a message differently depending on [gender]. Normally used as part
+   * of an Intl.message message that is to be translated.
+   */
+  static String gender(String gender,
+      {String male, String female, String other}) {
+    if (other == null) {
+      throw new ArgumentError("The 'other' named argument must be specified");
+    }
+    switch(gender) {
+      case "female" : return female == null ? other : female;
+      case "male" : return male == null ? other : male;
+      default: return other;
+    }
   }
 
   /**
@@ -274,13 +304,10 @@ class Intl {
    * usually) form from [cases] given the user [choice].
    */
   static String select(String choice, Map cases) {
-    if (cases.containsKey(choice)) {
-      return cases[choice];
-    } else if (cases.containsKey('other')){
-      return cases['other'];
-    } else {
-      return '';
-    }
+    var exact = cases[choice];
+    if (exact != null) return exact;
+    var other = cases["other"];
+    return (other == null) ? '' : other;
   }
 
   /**