Move `PluralForm` into a new module

Also replace the `panic` that could happen when an unknown plural
formula is used with returning `None`.

2 files changed, 35 insertions, 34 deletions

diff --git a/android/translations-converter/src/gettext/mod.rs b/android/translations-converter/src/gettext/mod.rs
index ae71e1ed7c..438f281cef 100644
--- a/android/translations-converter/src/gettext/mod.rs
+++ b/android/translations-converter/src/gettext/mod.rs
@@ -1,4 +1,5 @@
 mod msg_string;
+mod plural_form;
 
 use self::msg_string::MsgString;
 use lazy_static::lazy_static;
@@ -11,6 +12,8 @@ use std::{
     path::Path,
 };
 
+pub use self::plural_form::PluralForm;
+
 lazy_static! {
     static ref APOSTROPHE_VARIATION: Regex = Regex::new("’").unwrap();
     static ref ESCAPED_DOUBLE_QUOTES: Regex = Regex::new(r#"\\""#).unwrap();
@@ -24,16 +27,6 @@ pub struct Translation {
     entries: Vec<MsgEntry>,
 }
 
-/// Known plural forms.
-#[derive(Clone, Copy, Debug)]
-pub enum PluralForm {
-    Single,
-    SingularForOne,
-    SingularForZeroAndOne,
-    Polish,
-    Russian,
-}
-
 /// A message entry in a gettext translation file.
 #[derive(Clone, Debug)]
 pub struct MsgEntry {
@@ -151,7 +144,7 @@ impl Translation {
                 ["\"", header, "\\n\""] => {
                     if parsing_header {
                         if let Some(plural_formula) = parse_line(header, "Plural-Forms: ", ";") {
-                            plural_form = Some(PluralForm::from_formula(plural_formula));
+                            plural_form = PluralForm::from_formula(plural_formula);
                         }
                     }
                 }
@@ -198,29 +191,6 @@ impl IntoIterator for Translation {
     }
 }
 
-impl PluralForm {
-    /// Obtain an instance based on a known plural formula.
-    ///
-    /// Plural variants need to be obtained using a formula. However, some locales have known
-    /// formulas, so they can be represented as a known plural form. This constructor can return a
-    /// plural form based on the formulas that are known to be used in the project.
-    pub fn from_formula(formula: &str) -> Self {
-        match formula {
-            "nplurals=1; plural=0" => PluralForm::Single,
-            "nplurals=2; plural=(n != 1)" => PluralForm::SingularForOne,
-            "nplurals=2; plural=(n > 1)" => PluralForm::SingularForZeroAndOne,
-            "nplurals=4; plural=(n==1 ? 0 : (n%10>=2 && n%10<=4) && (n%100<12 || n%100>14) ? 1 : n!=1 && (n%10>=0 && n%10<=1) || (n%10>=5 && n%10<=9) || (n%100>=12 && n%100<=14) ? 2 : 3)" => {
-                PluralForm::Polish
-            }
-            "nplurals=4; plural=((n%10==1 && n%100!=11) ? 0 : ((n%10 >= 2 && n%10 <=4 && (n%100 < 12 || n%100 > 14)) ? 1 : ((n%10 == 0 || (n%10 >= 5 && n%10 <=9)) || (n%100 >= 11 && n%100 <= 14)) ? 2 : 3))" => {
-                PluralForm::Russian
-            }
-            other => panic!("Unknown plural formula: {}", other),
-        }
-    }
-}
-
-
 impl From<String> for MsgValue {
     fn from(string: String) -> Self {
         MsgValue::Invariant(string.into())
diff --git a/android/translations-converter/src/gettext/plural_form.rs b/android/translations-converter/src/gettext/plural_form.rs
new file mode 100644
index 0000000000..c55066c7b7
--- /dev/null
+++ b/android/translations-converter/src/gettext/plural_form.rs
@@ -0,0 +1,31 @@
+/// Known plural forms.
+#[derive(Clone, Copy, Debug)]
+pub enum PluralForm {
+    Single,
+    SingularForOne,
+    SingularForZeroAndOne,
+    Polish,
+    Russian,
+}
+
+impl PluralForm {
+    /// Obtain an instance based on a known plural formula.
+    ///
+    /// Plural variants need to be obtained using a formula. However, some locales have known
+    /// formulas, so they can be represented as a known plural form. This constructor can return a
+    /// plural form based on the formulas that are known to be used in the project.
+    pub fn from_formula(formula: &str) -> Option<Self> {
+        match formula {
+            "nplurals=1; plural=0" => Some(PluralForm::Single),
+            "nplurals=2; plural=(n != 1)" => Some(PluralForm::SingularForOne),
+            "nplurals=2; plural=(n > 1)" => Some(PluralForm::SingularForZeroAndOne),
+            "nplurals=4; plural=(n==1 ? 0 : (n%10>=2 && n%10<=4) && (n%100<12 || n%100>14) ? 1 : n!=1 && (n%10>=0 && n%10<=1) || (n%10>=5 && n%10<=9) || (n%100>=12 && n%100<=14) ? 2 : 3)" => {
+                Some(PluralForm::Polish)
+            }
+            "nplurals=4; plural=((n%10==1 && n%100!=11) ? 0 : ((n%10 >= 2 && n%10 <=4 && (n%100 < 12 || n%100 > 14)) ? 1 : ((n%10 == 0 || (n%10 >= 5 && n%10 <=9)) || (n%100 >= 11 && n%100 <= 14)) ? 2 : 3))" => {
+                Some(PluralForm::Russian)
+            }
+            _ => None
+        }
+    }
+}