Make DebugMethods pure; fix uses in flow and box (somewhat barbarically).

src/servo/dom/node.rs

@@ -52,11 +52,11 @@ impl Node {
 
 impl Node : DebugMethods {
     /* Dumps the subtree rooted at this node, for debugging. */
-    fn dump(&self) {
+    pure fn dump(&self) {
         self.dump_indent(0u);
     }
     /* Dumps the node tree, for debugging, with indentation. */
-    fn dump_indent(&self, indent: uint) {
+    pure fn dump_indent(&self, indent: uint) {
         let mut s = ~"";
         for uint::range(0u, indent) |_i| {
             s += ~"    ";
@@ -65,12 +65,15 @@ impl Node : DebugMethods {
         s += self.debug_str();
         debug!("%s", s);
 
+        // FIXME: this should have a pure version?
+        unsafe {
             for NodeTree.each_child(self) |kid| {
                 kid.dump_indent(indent + 1u) 
             }
         }
+    }
 
-    fn debug_str(&self) -> ~str {
+    pure fn debug_str(&self) -> ~str unsafe {
         do self.read |n| { fmt!("%?", n.kind) }
     }
 }

src/servo/layout/box.rs

@@ -576,12 +576,12 @@ impl RenderBox : RenderBoxMethods {
 }
 
 impl RenderBox : BoxedDebugMethods {
-    fn dump(@self) {
+    pure fn dump(@self) {
         self.dump_indent(0u);
     }
 
     /* Dumps the node tree, for debugging, with indentation. */
-    fn dump_indent(@self, indent: uint) {
+    pure fn dump_indent(@self, indent: uint) {
         let mut s = ~"";
         for uint::range(0u, indent) |_i| {
             s += ~"    ";
@@ -591,7 +591,7 @@ impl RenderBox : BoxedDebugMethods {
         debug!("%s", s);
     }
 
-    fn debug_str(@self) -> ~str {
+    pure fn debug_str(@self) -> ~str {
         let repr = match self {
             @GenericBox(*) => ~"GenericBox",
             @ImageBox(*) => ~"ImageBox",

src/servo/layout/debug.rs

@@ -1,11 +1,11 @@
 trait BoxedDebugMethods {
-    fn dump(@self);
+    pure fn dump(@self);
-    fn dump_indent(@self, ident: uint);
+    pure fn dump_indent(@self, ident: uint);
-    fn debug_str(@self) -> ~str;
+    pure fn debug_str(@self) -> ~str;
 }
 
 trait DebugMethods {
-    fn dump(&self);
+    pure fn dump(&self);
-    fn dump_indent(&self, ident: uint);
+    pure fn dump_indent(&self, ident: uint);
-    fn debug_str(&self) -> ~str;
+    pure fn debug_str(&self) -> ~str;
 }

src/servo/layout/flow.rs

@@ -242,12 +242,12 @@ impl FlowTree : tree::WriteMethods<@FlowContext> {
 
 
 impl FlowContext : BoxedDebugMethods {
-    fn dump(@self) {
+    pure fn dump(@self) {
         self.dump_indent(0u);
     }
 
     /** Dumps the flow tree, for debugging, with indentation. */
-    fn dump_indent(@self, indent: uint) {
+    pure fn dump_indent(@self, indent: uint) {
         let mut s = ~"|";
         for uint::range(0u, indent) |_i| {
             s += ~"---- ";
@@ -256,12 +256,15 @@ impl FlowContext : BoxedDebugMethods {
         s += self.debug_str();
         debug!("%s", s);
 
+        // FIXME: this should have a pure/const version?
+        unsafe {
             for FlowTree.each_child(self) |child| {
                 child.dump_indent(indent + 1u) 
             }
         }
+    }
     
-    fn debug_str(@self) -> ~str {
+    pure fn debug_str(@self) -> ~str {
         let repr = match *self {
             InlineFlow(*) => {
                 let mut s = self.inline().boxes.foldl(~"InlineFlow(children=", |s, box| {