Added defmulti

docs/contrib/index.rst

@@ -9,3 +9,4 @@ Contents:
 
    anaphoric
    loop
+   multi

docs/contrib/multi.rst

@@ -0,0 +1,23 @@
+========
+defmulti
+========
+
+.. versionadded:: 0.9.13
+
+`defmulti` lets you arity-overload a function by the given number of 
+args and/or kwargs. Inspired by clojures take on `defn`.
+
+.. code-block:: clj
+
+    => (require hy.contrib.multi)
+    =>   (defmulti fun
+    ...     ([a] a)
+    ...     ([a b] "a b")
+    ...     ([a b c] "a b c"))
+    => (fun 1 2 3)
+    'a b c'
+    => (fun a b)
+    "a b"
+    => (fun 1)
+    1
+

hy/contrib/dispatch/__init__.py

@@ -0,0 +1,50 @@
+# -*- encoding: utf-8 -*-
+#
+# Decorator for defmulti
+#
+# Copyright (c) 2014 Morten Linderud <mcfoxax@gmail.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+# DEALINGS IN THE SOFTWARE.
+
+from collections import defaultdict
+
+
+class MultiDispatch(object):
+    _fns = defaultdict(dict)
+
+    def __init__(self, fn):
+        self.fn = fn
+        self.__doc__ = fn.__doc__
+        if fn.__name__ not in self._fns[fn.__module__].keys():
+            self._fns[fn.__module__][fn.__name__] = {}
+        values = fn.__code__.co_varnames
+        self._fns[fn.__module__][fn.__name__][values] = fn
+
+    def is_fn(self, v, args, kwargs):
+        """Compare the given (checked fn) too the called fn"""
+        com = list(args) + list(kwargs.keys())
+        if len(com) == len(v):
+            return all([kw in com for kw in kwargs.keys()])
+        return False
+
+    def __call__(self, *args, **kwargs):
+        for i, fn in self._fns[self.fn.__module__][self.fn.__name__].items():
+            if self.is_fn(i, args, kwargs):
+                return fn(*args, **kwargs)
+        raise TypeError("No matching functions with this signature!")

hy/contrib/multi.hy

@@ -0,0 +1,41 @@
+;; Hy Arity-overloading
+;; Copyright (c) 2014 Morten Linderud <mcfoxax@gmail.com>
+
+;; Permission is hereby granted, free of charge, to any person obtaining a
+;; copy of this software and associated documentation files (the "Software"),
+;; to deal in the Software without restriction, including without limitation
+;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
+;; and/or sell copies of the Software, and to permit persons to whom the
+;; Software is furnished to do so, subject to the following conditions:
+
+;; The above copyright notice and this permission notice shall be included in
+;; all copies or substantial portions of the Software.
+
+;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+;; DEALINGS IN THE SOFTWARE.
+
+(import [collections [defaultdict]])
+(import [hy.models.string [HyString]])
+
+
+(defmacro defmulti [name &rest bodies]
+  (def comment (HyString))
+  (if (= (type (first bodies)) HyString)
+    (do (def comment (car bodies))
+        (def bodies (cdr bodies))))
+
+  (def ret `(do))
+  
+  (.append ret '(import [hy.contrib.dispatch [MultiDispatch]]))
+ 
+  (for [body bodies]
+    (def let-binds (car body))
+    (def body (cdr body))
+    (.append ret 
+        `(with-decorator MultiDispatch (defn ~name ~let-binds ~comment ~@body))))
+  ret)

tests/__init__.py

@@ -18,3 +18,4 @@ from .native_tests.contrib.anaphoric import *  # noqa
 from .native_tests.contrib.loop import *  # noqa
 from .native_tests.contrib.meth import *  # noqa
 from .native_tests.contrib.walk import *  # noqa
+from .native_tests.contrib.multi import *  # noqa

tests/native_tests/contrib/multi.hy

@@ -0,0 +1,57 @@
+;; Copyright (c) 2014 Morten Linderud <mcfoxax@gmail.com>
+ 
+;; Permission is hereby granted, free of charge, to any person obtaining a
+;; copy of this software and associated documentation files (the "Software"),
+;; to deal in the Software without restriction, including without limitation
+;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
+;; and/or sell copies of the Software, and to permit persons to whom the
+;; Software is furnished to do so, subject to the following conditions:
+
+;; The above copyright notice and this permission notice shall be included in
+;; all copies or substantial portions of the Software.
+
+;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+;; DEALINGS IN THE SOFTWARE.
+
+(require hy.contrib.multi)
+
+
+(defn test-basic-multi []
+  "NATIVE: Test a basic defmulti"
+  (defmulti fun
+    ([] "Hello!")
+    ([a] a)
+    ([a b] "a b")
+    ([a b c] "a b c"))
+
+  (assert (= (fun) "Hello!"))
+  (assert (= (fun "a") "a"))
+  (assert (= (fun "a" "b") "a b"))
+  (assert (= (fun "a" "b" "c") "a b c")))
+
+
+(defn test-kw-args []
+  "NATIVE: Test if kwargs are handled correctly"
+  (defmulti fun
+    ([a] a)
+    ([&optional [a "nop"] [b "p"]] (+ a b)))
+   
+  (assert (= (fun 1) 1))
+  (assert (= (apply fun [] {"a" "t"}) "t"))
+  (assert (= (apply fun ["hello "] {"b" "world"}) "hello world"))
+  (assert (= (apply fun [] {"a" "hello " "b" "world"}) "hello world")))
+
+
+(defn test-docs []
+  "NATIVE: Test if docs are properly handled"
+  (defmulti fun
+    "docs"
+    ([a] (print a))
+    ([a b] (print b)))
+  
+  (assert (= fun.--doc-- "docs")))