generic: new module functor

6 files changed, 57 insertions, 41 deletions

diff --git a/build.xml b/build.xml
index 524cfb57..581640d2 100644
--- a/build.xml
+++ b/build.xml
@@ -86,6 +86,7 @@
       <arg value="clojure.contrib.fcase"/>
       <arg value="clojure.contrib.generic.arithmetic"/>
       <arg value="clojure.contrib.generic.collection"/>
+      <arg value="clojure.contrib.generic.functor"/>
       <arg value="clojure.contrib.generic.math-functions"/>
       <arg value="clojure.contrib.import-static"/>
       <arg value="clojure.contrib.javadoc.browse"/>
diff --git a/src/clojure/contrib/gen_html_docs.clj b/src/clojure/contrib/gen_html_docs.clj
index c00d3513..a008a75a 100644
--- a/src/clojure/contrib/gen_html_docs.clj
+++ b/src/clojure/contrib/gen_html_docs.clj
@@ -484,6 +484,7 @@ emits the generated HTML to the path named by path."
      'clojure.contrib.fcase
      'clojure.contrib.generic.arithmetic
      'clojure.contrib.generic.collection
+     'clojure.contrib.generic.functor
      'clojure.contrib.generic.math-functions
      'clojure.contrib.import-static
      'clojure.contrib.javadoc
diff --git a/src/clojure/contrib/generic/collection.clj b/src/clojure/contrib/generic/collection.clj
index 53e316a3..7d521804 100644
--- a/src/clojure/contrib/generic/collection.clj
+++ b/src/clojure/contrib/generic/collection.clj
@@ -1,7 +1,7 @@
 ;; Generic interfaces for collection-related functions
 
 ;; by Konrad Hinsen
-;; last updated March 16, 2009
+;; last updated March 18, 2009
 
 ;; Copyright (c) Konrad Hinsen, 2009. All rights reserved.  The use
 ;; and distribution terms for this software are covered by the Eclipse
@@ -18,8 +18,8 @@
    with future release.
 
    This library defines generic versions of common collection-related functions
-   such as map or conj as multimethods that can be defined for any type."
-  (:refer-clojure :exclude [assoc conj dissoc empty get into map seq]))
+   as multimethods that can be defined for any type."
+  (:refer-clojure :exclude [assoc conj dissoc empty get into seq]))
 
 ;
 ; assoc
@@ -90,42 +90,16 @@
 ;
 ; into
 ;
-; This is a literal copy of into from clojure.core, but it is
-; evaluated with the functions from this namespace here!
-(declare seq)
-(defn into
+(defmulti into
   "Returns a new coll consisting of to-coll with all of the items of
   from-coll conjoined."
-  [to from]
-  (let [ret to items (seq from)]
-    (if items
-      (recur (conj ret (first items)) (next items))
-      ret)))
+   {:arglists '([to from])}
+  (fn [to from] (type to)))
 
-;
-; map
-;
-(defmulti map
-  "Applies function f to each element of coll and returns a collection
-   of the same kind as coll."
-   {:arglists '([f coll])}
-   (fn [f coll] (type coll)))
-
-(defmethod map clojure.lang.ISeq
-  [f coll]
-  (clojure.core/map f coll))
-
-(defmethod map clojure.lang.IPersistentVector
-  [f v]
-  (clojure.core/into (clojure.core/empty v) (clojure.core/map f v)))
-
-(defmethod map clojure.lang.IPersistentMap
-  [f m]
-  (clojure.core/into (clojure.core/empty m) (for [[k v] m] [k (f v)])))
-
-(defmethod map clojure.lang.IPersistentSet
-  [f s]
-  (clojure.core/into (clojure.core/empty s) (clojure.core/map f s)))
+(declare seq)
+(defmethod into :default
+  [to from]
+  (reduce conj to (seq from)))
 
 ;
 ; seq
diff --git a/src/clojure/contrib/generic/functor.clj b/src/clojure/contrib/generic/functor.clj
new file mode 100644
index 00000000..1198c510
--- /dev/null
+++ b/src/clojure/contrib/generic/functor.clj
@@ -0,0 +1,38 @@
+;; Generic interface for functors
+
+;; by Konrad Hinsen
+;; last updated March 18, 2009
+
+;; Copyright (c) Konrad Hinsen, 2009. All rights reserved.  The use
+;; and distribution terms for this software are covered by the Eclipse
+;; Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+;; which can be found in the file epl-v10.html at the root of this
+;; distribution.  By using this software in any fashion, you are
+;; agreeing to be bound by the terms of this license.  You must not
+;; remove this notice, or any other, from this software.
+
+(ns clojure.contrib.generic.functor
+  "Generic functor interface")
+
+
+(defmulti fmap
+  "Applies function f to each item in the data structure s and returns
+   a structure of the same kind."
+   {:arglists '([f s])}
+   (fn [f s] (type s)))
+
+(defmethod fmap clojure.lang.ISeq
+  [f s]
+  (map f s))
+
+(defmethod fmap clojure.lang.IPersistentVector
+  [f v]
+  (into (empty v) (map f v)))
+
+(defmethod fmap clojure.lang.IPersistentMap
+  [f m]
+  (into (empty m) (for [[k v] m] [k (f v)])))
+
+(defmethod fmap clojure.lang.IPersistentSet
+  [f s]
+  (into (empty s) (map f s)))
diff --git a/src/clojure/contrib/load_all.clj b/src/clojure/contrib/load_all.clj
index 9890803d..6cbdd872 100644
--- a/src/clojure/contrib/load_all.clj
+++ b/src/clojure/contrib/load_all.clj
@@ -44,6 +44,7 @@ except
 fcase
 generic.arithmetic
 generic.collection
+generic.functor
 generic.math-functions
 import-static
 javadoc.browse
diff --git a/src/clojure/contrib/types/examples.clj b/src/clojure/contrib/types/examples.clj
index 214f7e1c..8c56b1c5 100644
--- a/src/clojure/contrib/types/examples.clj
+++ b/src/clojure/contrib/types/examples.clj
@@ -9,7 +9,8 @@
 (ns clojure.contrib.types.examples
   (:use [clojure.contrib.types
 	 :only (deftype defadt match)])
-  (:require [clojure.contrib.generic.collection :as gc]))
+  (:require [clojure.contrib.generic.collection :as gc])
+  (:require [clojure.contrib.generic.functor :as gf]))
 
 ;
 ; Multisets implemented as maps to integers
@@ -74,15 +75,15 @@
 (depth empty-tree)
 (depth a-tree)
 
-; Algebraic data types with multimethods: map on a tree
-(defmethod gc/map ::tree
+; Algebraic data types with multimethods: fmap on a tree
+(defmethod gf/fmap ::tree
   [f t]
   (match t
     empty-tree  empty-tree
     (leaf v)    (leaf (f v))
-    (node l r)  (node (gc/map f l) (gc/map f r))))
+    (node l r)  (node (gf/fmap f l) (gf/fmap f r))))
 
-(gc/map str a-tree)
+(gf/fmap str a-tree)
 
 ;
 ; Nonsense examples to illustrate all the features of match