Add iter and iter_mut to LanguageRange

src/language/mod.rs

@@ -8,18 +8,35 @@ use crate::headers::HeaderValue;
 use std::{
     borrow::Cow,
     fmt::{self, Display},
+    slice,
     str::FromStr,
 };
 
 /// An RFC 4647 language range.
 #[derive(Debug, Clone, PartialEq)]
 pub struct LanguageRange {
-    pub(crate) tags: Vec<Cow<'static, str>>,
+    pub(crate) subtags: Vec<Cow<'static, str>>,
+}
+
+impl LanguageRange {
+    /// An iterator visiting all entries.
+    pub fn iter(&self) -> Iter<'_> {
+        Iter {
+            inner: self.subtags.iter(),
+        }
+    }
+
+    /// An iterator visiting all entries.
+    pub fn iter_mut(&mut self) -> IterMut<'_> {
+        IterMut {
+            inner: self.subtags.iter_mut(),
+        }
+    }
 }
 
 impl Display for LanguageRange {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let mut tags = self.tags.iter();
+        let mut tags = self.subtags.iter();
         if let Some(tag) = tags.next() {
             write!(f, "{}", tag)?;
 
@@ -31,6 +48,95 @@ impl Display for LanguageRange {
     }
 }
 
+/// A borrowing iterator over entries in `LanguageRange`.
+#[derive(Debug)]
+pub struct IntoIter {
+    inner: std::vec::IntoIter<Cow<'static, str>>,
+}
+
+impl Iterator for IntoIter {
+    type Item = Cow<'static, str>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+/// A lending iterator over entries in `LanguageRange`.
+#[derive(Debug)]
+pub struct Iter<'a> {
+    inner: slice::Iter<'a, Cow<'static, str>>,
+}
+
+impl<'a> Iterator for Iter<'a> {
+    type Item = &'a Cow<'static, str>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+/// A mutable iterator over entries in `LanguageRange`.
+#[derive(Debug)]
+pub struct IterMut<'a> {
+    inner: slice::IterMut<'a, Cow<'static, str>>,
+}
+
+impl<'a> Iterator for IterMut<'a> {
+    type Item = &'a mut Cow<'static, str>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+impl IntoIterator for LanguageRange {
+    type Item = Cow<'static, str>;
+    type IntoIter = IntoIter;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter {
+            inner: self.subtags.into_iter(),
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a LanguageRange {
+    type Item = &'a Cow<'static, str>;
+    type IntoIter = Iter<'a>;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a mut LanguageRange {
+    type Item = &'a mut Cow<'static, str>;
+    type IntoIter = IterMut<'a>;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter_mut()
+    }
+}
+
 impl From<LanguageRange> for HeaderValue {
     fn from(language: LanguageRange) -> Self {
         let s = language.to_string();
@@ -51,3 +157,16 @@ impl<'a> From<&'a str> for LanguageRange {
         Self::from_str(value).unwrap()
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_iter() -> crate::Result<()> {
+        let range: LanguageRange = "en-CA".parse().unwrap();
+        let subtags: Vec<_> = range.iter().collect();
+        assert_eq!(&subtags, &["en", "CA"]);
+        Ok(())
+    }
+}

src/language/parse.rs

@@ -40,20 +40,20 @@ pub(crate) fn parse(input: &str) -> crate::Result<LanguageRange> {
         input = rest;
     }
 
-    Ok(LanguageRange { tags })
+    Ok(LanguageRange { subtags: tags })
 }
 
 #[test]
 fn test() {
     let range = parse("en").unwrap();
-    assert_eq!(&range.tags, &["en"]);
+    assert_eq!(&range.subtags, &["en"]);
 
     let range = parse("en-CA").unwrap();
-    assert_eq!(&range.tags, &["en", "CA"]);
+    assert_eq!(&range.subtags, &["en", "CA"]);
 
     let range = parse("zh-Hant-CN-x-private1-private2").unwrap();
     assert_eq!(
-        &range.tags,
+        &range.subtags,
         &["zh", "Hant", "CN", "x", "private1", "private2"]
     );
 }