Convert our iterators to external iterators

Except util/tree.rs (see next commit).

4 files changed, 173 insertions, 146 deletions

diff --git a/src/components/gfx/text/glyph.rs b/src/components/gfx/text/glyph.rs
index d1373922a51..f1a494409af 100644
--- a/src/components/gfx/text/glyph.rs
+++ b/src/components/gfx/text/glyph.rs
@@ -14,6 +14,7 @@ use std::u16;
 use std::vec;
 use std::uint;
 use std::util;
+use std::iterator;
 use geom::point::Point2D;
 use extra::sort;
 
@@ -599,62 +600,24 @@ impl<'self> GlyphStore {
         self.entry_buffer[i] = entry;
     }
 
-    pub fn iter_glyphs_for_char_index(&'self self,
-                                  i: uint,
-                                  cb: &fn(uint, &GlyphInfo<'self>) -> bool)
-                                  -> bool {
-        assert!(i < self.entry_buffer.len());
-
-        let entry = &self.entry_buffer[i];
-        match entry.is_simple() {
-            true => { 
-                let proxy = &SimpleGlyphInfo(self, i);
-                cb(i, proxy);
-            },
-            false => {
-                let glyphs = self.detail_store.get_detailed_glyphs_for_entry(i,
-                                                                             entry.glyph_count());
-                for uint::range(0, glyphs.len()) |j| {
-                    let proxy = &DetailGlyphInfo(self, i, j as u16);
-                    cb(i, proxy);
-                }
-            }
-        }
-        true
+    pub fn iter_glyphs_for_char_index(&'self self, i: uint) -> GlyphIterator<'self> {
+        self.iter_glyphs_for_char_range(&Range::new(i, 1))
     }
 
-    pub fn iter_glyphs_for_char_range(&'self self,
-                                  range: &Range,
-                                  callback: &fn(uint, &GlyphInfo<'self>) -> bool)
-                                  -> bool {
-        if range.begin() >= self.entry_buffer.len() {
-            error!("iter_glyphs_for_range: range.begin beyond length!");
-            return false
+    pub fn iter_glyphs_for_char_range(&'self self, rang: &Range) -> GlyphIterator<'self> {
+        if rang.begin() >= self.entry_buffer.len() {
+            fail!("iter_glyphs_for_range: range.begin beyond length!");
         }
-        if range.end() > self.entry_buffer.len() {
-            error!("iter_glyphs_for_range: range.end beyond length!");
-            return false
+        if rang.end() > self.entry_buffer.len() {
+            fail!("iter_glyphs_for_range: range.end beyond length!");
         }
 
-        for range.eachi |i| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !self.iter_glyphs_for_char_index(i, |a, b| callback(a, b)) {
-                break
-            }
-        }
-
-        true
-    }
-
-    pub fn iter_all_glyphs(&'self self, callback: &fn(uint, &GlyphInfo<'self>) -> bool) -> bool {
-        for uint::range(0, self.entry_buffer.len()) |i| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !self.iter_glyphs_for_char_index(i, |a, b| callback(a, b)) {
-                break;
-            }
+        GlyphIterator {
+            store:       self,
+            char_index:  rang.begin(),
+            char_range:  rang.eachi(),
+            glyph_range: None
         }
-
-        true
     }
 
     // getter methods
@@ -713,3 +676,49 @@ impl<'self> GlyphStore {
         self.entry_buffer[i] = entry.set_can_break_before(t);
     }
 }
+
+pub struct GlyphIterator<'self> {
+    priv store:       &'self GlyphStore,
+    priv char_index:  uint,
+    priv char_range:  iterator::Range<uint>,
+    priv glyph_range: Option<iterator::Range<uint>>,
+}
+
+impl<'self> Iterator<(uint, GlyphInfo<'self>)> for GlyphIterator<'self> {
+    // I tried to start with something simpler and apply FlatMap, but the
+    // inability to store free variables in the FlatMap struct was problematic.
+
+    fn next(&mut self) -> Option<(uint, GlyphInfo<'self>)> {
+        // Would use 'match' here but it borrows contents in a way that
+        // interferes with mutation.
+        if self.glyph_range.is_some() {
+            match self.glyph_range.unwrap().next() {
+                Some(j) => Some((self.char_index,
+                    DetailGlyphInfo(self.store, self.char_index, j as u16))),
+                None => {
+                    // No more glyphs for current character.  Try to get another.
+                    self.glyph_range = None;
+                    self.next()
+                }
+            }
+        } else {
+            // No glyph range.  Look at next character.
+            match self.char_range.next() {
+                Some(i) => {
+                    self.char_index = i;
+                    assert!(i < self.store.entry_buffer.len());
+                    let entry = &self.store.entry_buffer[i];
+                    if entry.is_simple() {
+                        Some((self.char_index, SimpleGlyphInfo(self.store, i)))
+                    } else {
+                        let glyphs = self.store.detail_store
+                                     .get_detailed_glyphs_for_entry(i, entry.glyph_count());
+                        self.glyph_range = Some(range(0, glyphs.len()));
+                        self.next()
+                    }
+                },
+                None => None
+            }
+        }
+    }
+}
diff --git a/src/components/gfx/text/text_run.rs b/src/components/gfx/text/text_run.rs
index d3ea446fcf7..0688cb75b37 100644
--- a/src/components/gfx/text/text_run.rs
+++ b/src/components/gfx/text/text_run.rs
@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use std::vec::VecIterator;
+
 use font_context::FontContext;
 use geometry::Au;
 use text::glyph::GlyphStore;
@@ -41,6 +43,78 @@ impl SendableTextRun {
     }
 }
 
+pub struct SliceIterator<'self> {
+    priv glyph_iter: VecIterator<'self, Arc<GlyphStore>>,
+    priv range:      Range,
+    priv offset:     uint,
+}
+
+impl<'self> Iterator<(&'self GlyphStore, uint, Range)> for SliceIterator<'self> {
+    fn next(&mut self) -> Option<(&'self GlyphStore, uint, Range)> {
+        loop {
+            let slice_glyphs = self.glyph_iter.next();
+            if slice_glyphs.is_none() {
+                return None;
+            }
+            let slice_glyphs = slice_glyphs.unwrap().get();
+
+            let slice_range = Range::new(self.offset, slice_glyphs.char_len());
+            let mut char_range = self.range.intersect(&slice_range);
+            char_range.shift_by(-(self.offset.to_int()));
+
+            let old_offset = self.offset;
+            self.offset += slice_glyphs.char_len();
+            if !char_range.is_empty() {
+                return Some((slice_glyphs, old_offset, char_range))
+            }
+        }
+    }
+}
+
+pub struct LineIterator<'self> {
+    priv range:  Range,
+    priv clump:  Option<Range>,
+    priv slices: SliceIterator<'self>,
+}
+
+impl<'self> Iterator<Range> for LineIterator<'self> {
+    fn next(&mut self) -> Option<Range> {
+        // Loop until we hit whitespace and are in a clump.
+        loop {
+            match self.slices.next() {
+                Some((glyphs, offset, slice_range)) => {
+                    match (glyphs.is_whitespace(), self.clump) {
+                        (false, Some(ref mut c))  => {
+                            c.extend_by(slice_range.length().to_int());
+                        }
+                        (false, None) => {
+                            let mut c = slice_range;
+                            c.shift_by(offset.to_int());
+                            self.clump = Some(c);
+                        }
+                        (true, None)    => { /* chomp whitespace */ }
+                        (true, Some(c)) => {
+                            self.clump = None;
+                            // The final whitespace clump is not included.
+                            return Some(c);
+                        }
+                    }
+                },
+                None => {
+                    // flush any remaining chars as a line
+                    if self.clump.is_some() {
+                        let mut c = self.clump.take_unwrap();
+                        c.extend_to(self.range.end());
+                        return Some(c);
+                    } else {
+                        return None;
+                    }
+                }
+            }
+        }
+    }
+}
+
 impl<'self> TextRun {
     pub fn new(font: @mut Font, text: ~str, underline: bool) -> TextRun {
         let glyphs = TextRun::break_and_shape(font, text);
@@ -156,53 +230,19 @@ impl<'self> TextRun {
         max_piece_width
     }
 
-    pub fn iter_slices_for_range(&self,
-                                 range: &Range,
-                                 f: &fn(&GlyphStore, uint, &Range) -> bool)
-                                 -> bool {
-        let mut offset = 0;
-        for self.glyphs.iter().advance |slice_glyphs| {
-            // Determine the range of this slice that we need.
-            let slice_range = Range::new(offset, slice_glyphs.get().char_len());
-            let mut char_range = range.intersect(&slice_range);
-            char_range.shift_by(-(offset.to_int()));
-
-            let unwrapped_glyphs = slice_glyphs.get();
-            if !char_range.is_empty() {
-                if !f(unwrapped_glyphs, offset, &char_range) { break }
-            }
-            offset += unwrapped_glyphs.char_len();
+    pub fn iter_slices_for_range(&'self self, range: &Range) -> SliceIterator<'self> {
+        SliceIterator {
+            glyph_iter: self.glyphs.iter(),
+            range:      *range,
+            offset:     0,
         }
-        true
     }
 
-    pub fn iter_natural_lines_for_range(&self, range: &Range, f: &fn(&Range) -> bool) -> bool {
-        let mut clump = Range::new(range.begin(), 0);
-        let mut in_clump = false;
-
-        for self.iter_slices_for_range(range) |glyphs, offset, slice_range| {
-            match (glyphs.is_whitespace(), in_clump) {
-                (false, true)  => { clump.extend_by(slice_range.length().to_int()); }
-                (false, false) => {
-                    in_clump = true;
-                    clump = *slice_range;
-                    clump.shift_by(offset.to_int());
-                }
-                (true, false)  => { /* chomp whitespace */ }
-                (true, true)   => {
-                    in_clump = false;
-                    // The final whitespace clump is not included.
-                    if !f(&clump) { break }
-                }
-            }
-        }
-        
-        // flush any remaining chars as a line
-        if in_clump {
-            clump.extend_to(range.end());
-            f(&clump);
+    pub fn iter_natural_lines_for_range(&'self self, range: &Range) -> LineIterator<'self> {
+        LineIterator {
+            range:  *range,
+            clump:  None,
+            slices: self.iter_slices_for_range(range),
         }
-
-        true
     }
 }
diff --git a/src/components/main/layout/flow.rs b/src/components/main/layout/flow.rs
index 2d7db5d4a3c..6dc7e9409dc 100644
--- a/src/components/main/layout/flow.rs
+++ b/src/components/main/layout/flow.rs
@@ -238,6 +238,23 @@ impl TreeNode<FlowContext> for FlowData {
     }
 }
 
+pub struct BoxIterator {
+    priv boxes: ~[RenderBox],
+    priv index: uint,
+}
+
+impl Iterator<RenderBox> for BoxIterator {
+    fn next(&mut self) -> Option<RenderBox> {
+        if self.index >= self.boxes.len() {
+            None
+        } else {
+            let v = self.boxes[self.index].clone();
+            self.index += 1;
+            Some(v)
+        }
+    }
+}
+
 impl FlowData {
     pub fn new(id: int, node: AbstractNode<LayoutView>) -> FlowData {
         FlowData {
@@ -408,43 +425,15 @@ impl<'self> FlowContext {
         }
     }
 
-    pub fn iter_all_boxes(&self, cb: &fn(RenderBox) -> bool) -> bool {
-        match *self {
-            BlockFlow(block) => {
-                let block = &mut *block;
-                for block.box.iter().advance |box| {
-                    if !cb(*box) {
-                        break;
-                    }
-                }
-            }
-            InlineFlow(inline) => {
-                let inline = &mut *inline;
-                for inline.boxes.iter().advance |box| {
-                    if !cb(*box) {
-                        break;
-                    }
-                }
-            }
-            _ => fail!(fmt!("Don't know how to iterate node's RenderBoxes for %?", self))
-        }
-
-        true
-    }
-
-    pub fn iter_boxes_for_node(&self,
-                               node: AbstractNode<LayoutView>,
-                               callback: &fn(RenderBox) -> bool)
-                               -> bool {
-        for self.iter_all_boxes |box| {
-            if box.node() == node {
-                if !callback(box) {
-                    break;
-                }
-            }
+    pub fn iter_all_boxes(&self) -> BoxIterator {
+        BoxIterator {
+            boxes: match *self {
+                BlockFlow (block)  => block.box.map_default(~[], |&x| ~[x]),
+                InlineFlow(inline) => inline.boxes.clone(),
+                _ => fail!(fmt!("Don't know how to iterate node's RenderBoxes for %?", self))
+            },
+            index: 0,
         }
-
-        true
     }
 
     /// Dumps the flow tree for debugging.
diff --git a/src/components/main/layout/util.rs b/src/components/main/layout/util.rs
index e851cbb41b8..727523529f9 100644
--- a/src/components/main/layout/util.rs
+++ b/src/components/main/layout/util.rs
@@ -6,6 +6,9 @@ use layout::box::{RenderBox};
 use script::dom::node::{AbstractNode, LayoutView};
 use servo_util::range::Range;
 
+use std::iterator::Enumerate;
+use std::vec::VecIterator;
+
 pub struct NodeRange {
     node: AbstractNode<LayoutView>,
     range: Range,
@@ -39,22 +42,8 @@ impl ElementMapping {
         true
     }
 
-    pub fn eachi(&self, callback: &fn(i: uint, nr: &NodeRange) -> bool) -> bool {
-        for self.entries.iter().enumerate().advance |(i, nr)| {
-            if !callback(i, nr) {
-                break
-            }
-        }
-        true
-    }
-
-    pub fn eachi_mut(&self, callback: &fn(i: uint, nr: &NodeRange) -> bool) -> bool {
-        for self.entries.iter().enumerate().advance |(i, nr)| {
-            if !callback(i, nr) {
-                break
-            }
-        }
-        true
+    pub fn eachi<'a>(&'a self) -> Enumerate<VecIterator<'a, NodeRange>> {
+        self.entries.iter().enumerate()
     }
 
     pub fn repair_for_box_changes(&mut self, old_boxes: &[RenderBox], new_boxes: &[RenderBox]) {