Translate MultiDispatch from Python to Hy

Now we can put it into contrib.multi instead of its own module.

hy/contrib/dispatch/__init__.py

@@ -1,50 +0,0 @@
-# -*- 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

@@ -25,6 +25,35 @@
         [hy.models.list [HyList]]
         [hy.models.string [HyString]])
 
+(defclass MultiDispatch [object] [
+
+  _fns (defaultdict dict)
+
+  __init__ (fn [self f]
+    (setv self.f f)
+    (setv self.__doc__ f.__doc__)
+    (unless (in f.__name__ (.keys (get self._fns f.__module__)))
+      (setv (get self._fns f.__module__ f.__name__) {}))
+    (setv values f.__code__.co_varnames)
+    (setv (get self._fns f.__module__ f.__name__ values) f))
+
+  fn? (fn [self v args kwargs]
+    "Compare the given (checked fn) to the called fn"
+    (setv com (+ (list args) (list (.keys kwargs))))
+    (and
+      (= (len com) (len v))
+      (.issubset (frozenset (.keys kwargs)) com)))
+
+  __call__ (fn [self &rest args &kwargs kwargs]
+    (setv output None)
+    (for [[i f] (.items (get self._fns self.f.__module__ self.f.__name__))]
+      (when (.fn? self i args kwargs)
+        (setv output (apply f args kwargs))
+        (break)))
+    (if output
+      output
+      (raise (TypeError "No matching functions with this signature"))))])
+
 (defn multi-decorator [dispatch-fn]
   (setv inner (fn [&rest args &kwargs kwargs]
                 (setv dispatch-key (apply dispatch-fn args kwargs))
@@ -73,7 +102,7 @@
        (do (def comment (car bodies))
            (def bodies (cdr bodies))))
      (def ret `(do))
-     (.append ret '(import [hy.contrib.dispatch [MultiDispatch]]))
+     (.append ret '(import [hy.contrib.multi [MultiDispatch]]))
      (for [body bodies]
        (def let-binds (car body))
        (def body (cdr body))