Improved file load times.

There was a regression after switching to ropes.  Now it's pretty much
back to pre-rope load times.

src/buffer/line.rs

@@ -2,7 +2,7 @@
 
 use std::mem;
 use super::rope::{Rope, RopeGraphemeIter};
-use string_utils::is_line_ending;
+use string_utils::{is_line_ending, grapheme_count};
 
 
 /// A single line of text
@@ -100,7 +100,7 @@ impl Line {
     }
     
     
-    pub fn new_from_str_unchecked(text: &str) -> Line {
+    pub fn new_from_str_with_count_unchecked(text: &str, count: usize) -> Line {
         let mut ending = LineEnding::None;
         
         let bytes = text.as_bytes();
@@ -175,8 +175,9 @@ impl Line {
         }
         
         // Create and return Line
+        let cnt = if ending == LineEnding::None { count } else { count - 1 };
         return Line {
-            text: Rope::new_from_str(&text[..(bytes.len()-le_size)]),
+            text: Rope::new_from_str_with_count(&text[..(bytes.len()-le_size)], cnt),
             ending: ending,
         };
     }
@@ -189,7 +190,7 @@ impl Line {
         // TODO: this can be smarter, and can pass the string
         // directly to the Rope after taking off any line
         // endings.
-        return Line::new_from_str_unchecked(text.as_slice());
+        return Line::new_from_str_with_count_unchecked(text.as_slice(), grapheme_count(text.as_slice()));
     }
     
     

src/buffer/mod.rs

@@ -73,7 +73,7 @@ impl Buffer {
             
             if a != b {
                 let substr = &string[a..b];
-                let line = Line::new_from_str_unchecked(substr);
+                let line = Line::new_from_str_with_count_unchecked(substr, count);
                 let node = BufferNode::new_from_line_with_count_unchecked(line, count);
                 buf.append_leaf_node_unchecked(node);
             }

src/buffer/rope.rs

@@ -32,6 +32,7 @@ impl Rope {
             tree_height: 1,
         }
     }
+    
 
     /// Creates a new rope from a string slice    
     pub fn new_from_str(s: &str) -> Rope {
@@ -106,6 +107,19 @@ impl Rope {
         return rope;
     }
     
+    pub fn new_from_str_with_count(s: &str, count: usize) -> Rope {
+        if count <= MAX_NODE_SIZE {
+            Rope {
+                data: RopeData::Leaf(String::from_str(s)),
+                grapheme_count_: count,
+                tree_height: 1,
+            }
+        }
+        else {
+            Rope::new_from_str(s)
+        }
+    }
+    
     /// Creates a new rope from a string, consuming the string
     pub fn new_from_string(s: String) -> Rope {
         // TODO: special case short strings?