From 063db3580697bb4c804ceef9fb13de4f0f5e8832 Mon Sep 17 00:00:00 2001
From: Corey Farwell <coreyf@rwell.org>
Date: Wed, 13 Sep 2017 19:38:32 -0500
Subject: [PATCH] servo: Merge #18494 - Implement `size_hint` for more
 iterators (from frewsxcv:frewsxcv-size-hint); r=jdm

```
implement size hint for
more iterators because why
not we like fast things
```

Source-Repo: https://github.com/servo/servo
Source-Revision: bb2030a49314433c1b31f853e4fa50afa241b596

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : fb164a6e8e51ebba14d97ee7600567b3b517dc30
---
 servo/components/layout/flow.rs                        | 4 ++++
 servo/components/layout/inline.rs                      | 4 ++++
 servo/components/script/dom/htmlselectelement.rs       | 8 ++++++++
 servo/components/script/dom/servoparser/mod.rs         | 4 ++++
 servo/components/style/font_face.rs                    | 4 ++++
 servo/components/style/properties/declaration_block.rs | 4 ++++
 servo/components/style/stylesheet_set.rs               | 4 ++++
 servo/components/style/values/computed/mod.rs          | 4 ++++
 8 files changed, 36 insertions(+)

diff --git a/servo/components/layout/flow.rs b/servo/components/layout/flow.rs
index f4c545ec730b..a2a057614380 100644
--- a/servo/components/layout/flow.rs
+++ b/servo/components/layout/flow.rs
@@ -765,6 +765,10 @@ impl<'a> Iterator for AbsoluteDescendantIter<'a> {
     fn next(&mut self) -> Option<&'a mut Flow> {
         self.iter.next().map(|info| FlowRef::deref_mut(&mut info.flow))
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
 }
 
 pub type AbsoluteDescendantOffsetIter<'a> = Zip<AbsoluteDescendantIter<'a>, IterMut<'a, Au>>;
diff --git a/servo/components/layout/inline.rs b/servo/components/layout/inline.rs
index f07943fd3218..c38693c33404 100644
--- a/servo/components/layout/inline.rs
+++ b/servo/components/layout/inline.rs
@@ -979,6 +979,10 @@ impl InlineFlow {
                         self.iter.next()
                     }
                 }
+
+                fn size_hint(&self) -> (usize, Option<usize>) {
+                    self.iter.size_hint()
+                }
             }
 
             // If the bidi embedding direction is opposite the layout direction, lay out this
diff --git a/servo/components/script/dom/htmlselectelement.rs b/servo/components/script/dom/htmlselectelement.rs
index fd5a864862af..9db953162970 100755
--- a/servo/components/script/dom/htmlselectelement.rs
+++ b/servo/components/script/dom/htmlselectelement.rs
@@ -440,4 +440,12 @@ impl<I, J, K, T> Iterator for Choice3<I, J, K>
             Choice3::Third(ref mut k) => k.next(),
         }
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        match *self {
+            Choice3::First(ref i) => i.size_hint(),
+            Choice3::Second(ref j) => j.size_hint(),
+            Choice3::Third(ref k) => k.size_hint(),
+        }
+    }
 }
diff --git a/servo/components/script/dom/servoparser/mod.rs b/servo/components/script/dom/servoparser/mod.rs
index 241179ed6244..d0e08664e73a 100644
--- a/servo/components/script/dom/servoparser/mod.rs
+++ b/servo/components/script/dom/servoparser/mod.rs
@@ -487,6 +487,10 @@ impl<I> Iterator for FragmentParsingResult<I>
         next.remove_self();
         Some(next)
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
 }
 
 #[derive(HeapSizeOf, JSTraceable, PartialEq)]
diff --git a/servo/components/style/font_face.rs b/servo/components/style/font_face.rs
index c12934a3b063..30eb242a6d4f 100644
--- a/servo/components/style/font_face.rs
+++ b/servo/components/style/font_face.rs
@@ -170,6 +170,10 @@ impl Iterator for EffectiveSources {
     fn next(&mut self) -> Option<Source> {
         self.0.pop()
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.0.len(), Some(self.0.len()))
+    }
 }
 
 struct FontFaceRuleParser<'a, 'b: 'a> {
diff --git a/servo/components/style/properties/declaration_block.rs b/servo/components/style/properties/declaration_block.rs
index a87b87fe9db9..15573cc6aefa 100644
--- a/servo/components/style/properties/declaration_block.rs
+++ b/servo/components/style/properties/declaration_block.rs
@@ -99,6 +99,10 @@ impl<'a> Iterator for DeclarationImportanceIterator<'a> {
         self.iter.next().map(|(decl, important)|
             (decl, if important { Importance::Important } else { Importance::Normal }))
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
 }
 
 impl<'a> DoubleEndedIterator for DeclarationImportanceIterator<'a> {
diff --git a/servo/components/style/stylesheet_set.rs b/servo/components/style/stylesheet_set.rs
index 328237ccbaec..4b8b177b554f 100644
--- a/servo/components/style/stylesheet_set.rs
+++ b/servo/components/style/stylesheet_set.rs
@@ -45,6 +45,10 @@ where
     fn next(&mut self) -> Option<Self::Item> {
         self.0.next().map(|entry| &entry.sheet)
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.0.size_hint()
+    }
 }
 
 /// An iterator over the flattened view of the stylesheet collections.
diff --git a/servo/components/style/values/computed/mod.rs b/servo/components/style/values/computed/mod.rs
index cad3db03aa74..a6c828b14b80 100644
--- a/servo/components/style/values/computed/mod.rs
+++ b/servo/components/style/values/computed/mod.rs
@@ -198,6 +198,10 @@ impl<'a, 'cx, 'cx_a: 'cx, S: ToComputedValue + 'a> Iterator for ComputedVecIter<
             None
         }
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.values.len(), Some(self.values.len()))
+    }
 }
 
 /// A trait to represent the conversion between computed and specified values.