Deleted fun_treemap

@thestinger and I talked about this in IRC. There are a couple of use
cases for a persistent map, but they aren't common enough to justify
inclusion in libextra and vary enough that they would require multiple
implementations anyways.

In any case, fun_treemap in its current state is basically useless.

src/libextra/extra.rs

@@ -55,7 +55,6 @@ pub mod flatpipes;
 
 pub mod container;
 pub mod bitv;
-pub mod fun_treemap;
 pub mod list;
 pub mod ringbuf;
 pub mod priority_queue;

src/libextra/fun_treemap.rs

@@ -1,84 +0,0 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-/*!
- * A functional key,value store that works on anything.
- *
- * This works using a binary search tree. In the first version, it's a
- * very naive algorithm, but it will probably be updated to be a
- * red-black tree or something else.
- *
- * This is copied and modified from treemap right now. It's missing a lot
- * of features.
- */
-
-
-use std::cmp::{Eq, Ord};
-use std::option::{Some, None};
-
-pub type Treemap<K, V> = @TreeNode<K, V>;
-
-enum TreeNode<K, V> {
-    Empty,
-    Node(@K, @V, @TreeNode<K, V>, @TreeNode<K, V>)
-}
-
-/// Create a treemap
-pub fn init<K: 'static, V: 'static>() -> Treemap<K, V> {
-    @Empty
-}
-
-/// Insert a value into the map
-pub fn insert<K:Eq + Ord + 'static,
-              V:'static>(
-              m: Treemap<K, V>,
-              k: K,
-              v: V)
-              -> Treemap<K, V> {
-    @match m {
-        @Empty => Node(@k, @v, @Empty, @Empty),
-        @Node(kk, vv, left, right) => cond!(
-            (k <  *kk) { Node(kk, vv, insert(left, k, v), right) }
-            (k == *kk) { Node(kk, @v, left, right)               }
-            _          { Node(kk, vv, left, insert(right, k, v)) }
-        )
-    }
-}
-
-/// Find a value based on the key
-pub fn find<K:Eq + Ord + 'static,
-            V:Clone + 'static>(
-            m: Treemap<K, V>,
-            k: K)
-            -> Option<V> {
-    match *m {
-        Empty => None,
-        Node(kk, v, left, right) => cond!(
-            (k == *kk) { Some((*v).clone()) }
-            (k <  *kk) { find(left, k)  }
-            _          { find(right, k) }
-        )
-    }
-}
-
-/// Visit all pairs in the map in order.
-pub fn traverse<K, V>(m: Treemap<K, V>, f: &fn(&K, &V)) {
-    match *m {
-        Empty => (),
-        // Previously, this had what looked like redundant
-        // matches to me, so I changed it. but that may be a
-        // de-optimization -- tjc
-        Node(@ref k, @ref v, left, right) => {
-            traverse(left, |k,v| f(k,v));
-            f(k, v);
-            traverse(right, |k,v| f(k,v));
-        }
-    }
-}