[librsvg: 2/8] Add a DeclarationList.iter() method

[Federico Mena Quintero <federico src gnome org>]

commit ebe3479f9d8b2c98c00a597edc92e259ed054bb2
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri May 3 13:15:25 2019 -0500

    Add a DeclarationList.iter() method

 rsvg_internals/src/css.rs | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)
---
diff --git a/rsvg_internals/src/css.rs b/rsvg_internals/src/css.rs
index 00032b24..986d0db5 100644
--- a/rsvg_internals/src/css.rs
+++ b/rsvg_internals/src/css.rs
@@ -1,5 +1,5 @@
 use cssparser::{Parser, ParserInput};
-use std::collections::hash_map::Entry;
+use std::collections::hash_map::{Entry, Iter as HashMapIter};
 use std::collections::{HashMap, HashSet};
 use std::ptr;
 use std::str::{self, FromStr};
@@ -53,6 +53,20 @@ impl DeclarationList {
             }
         }
     }
+
+    pub fn iter(&self) -> DeclarationListIter {
+        DeclarationListIter(self.declarations.iter())
+    }
+}
+
+pub struct DeclarationListIter<'a>(HashMapIter<'a, Attribute, Declaration>);
+
+impl<'a> Iterator for DeclarationListIter<'a> {
+    type Item = &'a Declaration;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next().map(|(_attribute, declaration)| declaration)
+    }
 }
 
 impl CssRules {
@@ -146,7 +160,7 @@ impl CssRules {
         important_styles: &mut HashSet<Attribute>,
     ) -> bool {
         if let Some(decl_list) = self.selectors_to_declarations.get(selector) {
-            for (_, declaration) in decl_list.declarations.iter() {
+            for declaration in decl_list.iter() {
                 values.set_property_from_declaration(declaration, important_styles);
             }