From 2d863abc854f515253d72f12b630c837fb8e56eb Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Mon, 17 Jul 2017 13:34:39 -0700
Subject: [PATCH 1/6] Implement #* and #** unpacking

---
 conftest.py                           |  5 +-
 hy/compiler.py                        | 91 +++++++++++++++++++++++----
 hy/lex/lexer.py                       |  1 +
 hy/lex/parser.py                      | 16 +++++
 tests/native_tests/language.hy        | 12 ++++
 tests/native_tests/py35_only_tests.hy | 26 ++++++++
 tests/native_tests/py3_only_tests.hy  | 10 +++
 tests/test_bin.py                     | 15 ++---
 8 files changed, 155 insertions(+), 21 deletions(-)
 create mode 100644 tests/native_tests/py35_only_tests.hy

diff --git a/conftest.py b/conftest.py
index 72fa553..0735cf7 100644
--- a/conftest.py
+++ b/conftest.py
@@ -1,12 +1,13 @@
 import _pytest
 import hy
-from hy._compat import PY3
+from hy._compat import PY3, PY35
 
 def pytest_collect_file(parent, path):
     if (path.ext == ".hy"
             and "/tests/native_tests/" in path.dirname + "/"
             and path.basename != "__init__.hy"
-            and not ("py3_only" in path.basename and not PY3)):
+            and not ("py3_only" in path.basename and not PY3)
+            and not ("py35_only" in path.basename and not PY35)):
         m = _pytest.python.pytest_pycollect_makemodule(path, parent)
         # Spoof the module name to avoid hitting an assertion in pytest.
         m.name = m.name[:-len(".hy")] + ".py"
diff --git a/hy/compiler.py b/hy/compiler.py
index b990332..97a4c73 100755
--- a/hy/compiler.py
+++ b/hy/compiler.py
@@ -359,6 +359,13 @@ def checkargs(exact=None, min=None, max=None, even=None, multiple=None):
     return _dec
 
 
+def is_unpack(kind, x):
+    return (isinstance(x, HyExpression)
+            and len(x) > 0
+            and isinstance(x[0], HySymbol)
+            and x[0] == "unpack_" + kind)
+
+
 class HyASTCompiler(object):
 
     def __init__(self, module_name):
@@ -441,7 +448,8 @@ class HyASTCompiler(object):
 
         raise HyCompileError(Exception("Unknown type: `%s'" % _type))
 
-    def _compile_collect(self, exprs, with_kwargs=False):
+    def _compile_collect(self, exprs, with_kwargs=False, dict_display=False,
+                         oldpy_unpack=False):
         """Collect the expression contexts from a list of compiled expression.
 
         This returns a list of the expression contexts, and the sum of the
@@ -451,10 +459,39 @@ class HyASTCompiler(object):
         compiled_exprs = []
         ret = Result()
         keywords = []
+        oldpy_starargs = None
+        oldpy_kwargs = None
 
         exprs_iter = iter(exprs)
         for expr in exprs_iter:
-            if with_kwargs and isinstance(expr, HyKeyword):
+
+            if not PY35 and oldpy_unpack and is_unpack("iterable", expr):
+                if oldpy_starargs:
+                    raise HyTypeError(expr, "Pythons < 3.5 allow only one "
+                                            "`unpack-iterable` per call")
+                oldpy_starargs = self.compile(expr[1])
+                ret += oldpy_starargs
+                oldpy_starargs = oldpy_starargs.force_expr
+
+            elif is_unpack("mapping", expr):
+                ret += self.compile(expr[1])
+                if PY35:
+                    if dict_display:
+                        compiled_exprs.append(None)
+                        compiled_exprs.append(ret.force_expr)
+                    elif with_kwargs:
+                        keywords.append(ast.keyword(
+                            arg=None,
+                            value=ret.force_expr,
+                            lineno=expr.start_line,
+                            col_offset=expr.start_column))
+                elif oldpy_unpack:
+                    if oldpy_kwargs:
+                        raise HyTypeError(expr, "Pythons < 3.5 allow only one "
+                                                "`unpack-mapping` per call")
+                    oldpy_kwargs = ret.force_expr
+
+            elif with_kwargs and isinstance(expr, HyKeyword):
                 try:
                     value = next(exprs_iter)
                 except StopIteration:
@@ -474,11 +511,15 @@ class HyASTCompiler(object):
                                             value=compiled_value.force_expr,
                                             lineno=expr.start_line,
                                             col_offset=expr.start_column))
+
             else:
                 ret += self.compile(expr)
                 compiled_exprs.append(ret.force_expr)
 
-        return compiled_exprs, ret, keywords
+        if oldpy_unpack:
+            return compiled_exprs, ret, keywords, oldpy_starargs, oldpy_kwargs
+        else:
+            return compiled_exprs, ret, keywords
 
     def _compile_branch(self, exprs):
         return _branch(self.compile(expr) for expr in exprs)
@@ -610,6 +651,9 @@ class HyASTCompiler(object):
             new_name = ast.Subscript(value=name.value, slice=name.slice)
         elif isinstance(name, ast.Attribute):
             new_name = ast.Attribute(value=name.value, attr=name.attr)
+        elif PY3 and isinstance(name, ast.Starred):
+            new_name = ast.Starred(
+                value=self._storeize(expr, name.value, func))
         else:
             raise HyTypeError(expr,
                               "Can't assign or delete a %s" %
@@ -717,6 +761,23 @@ class HyASTCompiler(object):
         raise HyTypeError(expr,
                           "`%s' can't be used at the top-level" % expr[0])
 
+    @builds("unpack_iterable")
+    @checkargs(exact=1)
+    def compile_unpack_iterable(self, expr):
+        if not PY3:
+            raise HyTypeError(expr, "`unpack-iterable` isn't allowed here")
+        ret = self.compile(expr[1])
+        ret += ast.Starred(value=ret.force_expr,
+                           lineno=expr.start_line,
+                           col_offset=expr.start_column,
+                           ctx=ast.Load())
+        return ret
+
+    @builds("unpack_mapping")
+    @checkargs(exact=1)
+    def compile_unpack_mapping(self, expr):
+        raise HyTypeError(expr, "`unpack-mapping` isn't allowed here")
+
     @builds("do")
     def compile_do(self, expression):
         expression.pop(0)
@@ -2001,9 +2062,15 @@ class HyASTCompiler(object):
             return self._compile_keyword_call(expression)
 
         if isinstance(fn, HySymbol):
-            ret = self.compile_atom(fn, expression)
-            if ret:
-                return ret
+            # First check if `fn` is a special form, unless it has an
+            # `unpack_iterable` in it, since Python's operators (`+`,
+            # etc.) can't unpack. An exception to this exception is that
+            # tuple literals (`,`) can unpack.
+            if fn == "," or not (
+                    any(is_unpack("iterable", x) for x in expression[1:])):
+                ret = self.compile_atom(fn, expression)
+                if ret:
+                    return ret
 
             if fn.startswith("."):
                 # (.split "test test") -> "test test".split()
@@ -2054,14 +2121,14 @@ class HyASTCompiler(object):
         else:
             with_kwargs = True
 
-        args, ret, kwargs = self._compile_collect(expression[1:],
-                                                  with_kwargs)
+        args, ret, keywords, oldpy_starargs, oldpy_kwargs = self._compile_collect(
+            expression[1:], with_kwargs, oldpy_unpack=True)
 
         ret += ast.Call(func=func.expr,
                         args=args,
-                        keywords=kwargs,
-                        starargs=None,
-                        kwargs=None,
+                        keywords=keywords,
+                        starargs=oldpy_starargs,
+                        kwargs=oldpy_kwargs,
                         lineno=expression.start_line,
                         col_offset=expression.start_column)
 
@@ -2583,7 +2650,7 @@ class HyASTCompiler(object):
 
     @builds(HyDict)
     def compile_dict(self, m):
-        keyvalues, ret, _ = self._compile_collect(m)
+        keyvalues, ret, _ = self._compile_collect(m, dict_display=True)
 
         ret += ast.Dict(lineno=m.start_line,
                         col_offset=m.start_column,
diff --git a/hy/lex/lexer.py b/hy/lex/lexer.py
index c6b5636..9779eda 100755
--- a/hy/lex/lexer.py
+++ b/hy/lex/lexer.py
@@ -26,6 +26,7 @@ lg.add('QUASIQUOTE', r'`%s' % end_quote)
 lg.add('UNQUOTESPLICE', r'~@%s' % end_quote)
 lg.add('UNQUOTE', r'~%s' % end_quote)
 lg.add('HASHBANG', r'#!.*[^\r\n]')
+lg.add('HASHSTARS', r'#\*+')
 lg.add('HASHOTHER', r'#%s' % identifier)
 
 # A regexp which matches incomplete strings, used to support
diff --git a/hy/lex/parser.py b/hy/lex/parser.py
index 1be896b..d60cec5 100755
--- a/hy/lex/parser.py
+++ b/hy/lex/parser.py
@@ -197,6 +197,22 @@ def term_unquote_splice(p):
     return HyExpression([HySymbol("unquote_splice"), p[1]])
 
 
+@pg.production("term : HASHSTARS term")
+@set_quote_boundaries
+def term_hashstars(p):
+    n_stars = len(p[0].getstr()[1:])
+    if n_stars == 1:
+        sym = "unpack_iterable"
+    elif n_stars == 2:
+        sym = "unpack_mapping"
+    else:
+        raise LexException(
+            "Too many stars in `#*` construct (if you want to unpack a symbol "
+            "beginning with a star, separate it with whitespace)",
+            p[0].source_pos.lineno, p[0].source_pos.colno)
+    return HyExpression([HySymbol(sym), p[1]])
+
+
 @pg.production("term : HASHOTHER term")
 @set_quote_boundaries
 def hash_other(p):
diff --git a/tests/native_tests/language.hy b/tests/native_tests/language.hy
index cbef01e..a284b39 100644
--- a/tests/native_tests/language.hy
+++ b/tests/native_tests/language.hy
@@ -369,6 +369,18 @@
   (assert (is (isfile ".") False)))
 
 
+(defn test-star-unpacking []
+  ; Python 3-only forms of unpacking are in py3_only_tests.hy
+  (setv l [1 2 3])
+  (setv d {"a" "x" "b" "y"})
+  (defn fun [&optional x1 x2 x3 x4 a b c] [x1 x2 x3 x4 a b c])
+  (assert (= (fun 5 #* l) [5 1 2 3 None None None]))
+  (assert (= (+ #* l) 6))
+  (assert (= (fun 5 #** d) [5 None None None "x" "y" None]))
+  (assert (= (fun 5 #* l #** d) [5 1 2 3 "x" "y" None])))
+
+
+
 (defn test-kwargs []
   "NATIVE: test kwargs things."
   (assert (= (apply kwtest [] {"one" "two"}) {"one" "two"}))
diff --git a/tests/native_tests/py35_only_tests.hy b/tests/native_tests/py35_only_tests.hy
new file mode 100644
index 0000000..716a9f8
--- /dev/null
+++ b/tests/native_tests/py35_only_tests.hy
@@ -0,0 +1,26 @@
+;; Copyright 2017 the authors.
+;; This file is part of Hy, which is free software licensed under the Expat
+;; license. See the LICENSE.
+
+;; Tests where the emitted code relies on Python ≥3.5.
+;; conftest.py skips this file when running on Python <3.5.
+
+
+(defn test-unpacking-pep448-1star []
+  (setv l [1 2 3])
+  (setv p [4 5])
+  (assert (= ["a" #*l "b" #*p #*l] ["a" 1 2 3 "b" 4 5 1 2 3]))
+  (assert (= (, "a" #*l "b" #*p #*l) (, "a" 1 2 3 "b" 4 5 1 2 3)))
+  (assert (= #{"a" #*l "b" #*p #*l} #{"a" "b" 1 2 3 4 5}))
+  (defn f [&rest args] args)
+  (assert (= (f "a" #*l "b" #*p #*l) (, "a" 1 2 3 "b" 4 5 1 2 3)))
+  (assert (= (+ #*l #*p) 15))
+  (assert (= (and #*l) 3)))
+
+
+(defn test-unpacking-pep448-2star []
+  (setv d1 {"a" 1 "b" 2})
+  (setv d2 {"c" 3 "d" 4})
+  (assert (= {1 "x" #**d1 #**d2 2 "y"} {"a" 1 "b" 2 "c" 3 "d" 4 1 "x" 2 "y"}))
+  (defn fun [&optional a b c d e f] [a b c d e f])
+  (assert (= (fun #**d1 :e "eee" #**d2) [1 2 3 4 "eee" None])))
diff --git a/tests/native_tests/py3_only_tests.hy b/tests/native_tests/py3_only_tests.hy
index b376f6c..b338ffa 100644
--- a/tests/native_tests/py3_only_tests.hy
+++ b/tests/native_tests/py3_only_tests.hy
@@ -37,6 +37,16 @@
              (, 1 2 (, 3 4)  5 {"bar" 6 "quux" 7}))))
 
 
+(defn test-extended-unpacking-1star-lvalues []
+  (setv [x #*y] [1 2 3 4])
+  (assert (= x 1))
+  (assert (= y [2 3 4]))
+  (setv [a #*b c] "ghijklmno")
+  (assert (= a "g"))
+  (assert (= b (list "hijklmn")))
+  (assert (= c "o")))
+
+
 (defn test-yield-from []
   "NATIVE: testing yield from"
   (defn yield-from-test []
diff --git a/tests/test_bin.py b/tests/test_bin.py
index c2e31e9..6df4d43 100644
--- a/tests/test_bin.py
+++ b/tests/test_bin.py
@@ -7,7 +7,7 @@
 import os
 import subprocess
 import re
-from hy._compat import PY3
+from hy._compat import PY3, PY35
 from hy.importer import get_bytecode_path
 import pytest
 
@@ -210,12 +210,13 @@ def test_hy2py():
             if f.endswith(".hy"):
                 if f == "py3_only_tests.hy" and not PY3:
                     continue
-                else:
-                    i += 1
-                    output, err = run_cmd("hy2py -s -a " +
-                                          os.path.join(dirpath, f))
-                    assert len(output) > 1, f
-                    assert len(err) == 0, f
+                if f == "py35_only_tests.hy" and not PY35:
+                    continue
+                i += 1
+                output, err = run_cmd("hy2py -s -a " +
+                                      os.path.join(dirpath, f))
+                assert len(output) > 1, f
+                assert len(err) == 0, f
     assert i
 
 

From 75e4ad8304ac8849408974b5df3f9ed310f0befa Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Sat, 15 Jul 2017 16:28:31 -0700
Subject: [PATCH 2/6] Remove uses of `apply` from /hy

---
 hy/contrib/loop.hy    |  2 +-
 hy/contrib/multi.hy   |  8 ++++----
 hy/contrib/profile.hy |  4 ++--
 hy/core/language.hy   | 18 +++++++++---------
 hy/core/macros.hy     |  2 +-
 5 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/hy/contrib/loop.hy b/hy/contrib/loop.hy
index 9ab9eb8..3417256 100644
--- a/hy/contrib/loop.hy
+++ b/hy/contrib/loop.hy
@@ -27,7 +27,7 @@
     (when (not (first active))
       (assoc active 0 True)
       (while (> (len accumulated) 0)
-        (setv result (apply f (.pop accumulated))))
+        (setv result (f #* (.pop accumulated))))
       (assoc active 0 False)
       result)))
 
diff --git a/hy/contrib/multi.hy b/hy/contrib/multi.hy
index 639c96a..8c89486 100644
--- a/hy/contrib/multi.hy
+++ b/hy/contrib/multi.hy
@@ -29,7 +29,7 @@
     (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))
+        (setv output (f #* args #** kwargs))
         (break)))
     (if output
       output
@@ -37,10 +37,10 @@
 
 (defn multi-decorator [dispatch-fn]
   (setv inner (fn [&rest args &kwargs kwargs]
-                (setv dispatch-key (apply dispatch-fn args kwargs))
+                (setv dispatch-key (dispatch-fn #* args #** kwargs))
                 (if (in dispatch-key inner.--multi--)
-                  (apply (get inner.--multi-- dispatch-key) args kwargs)
-                  (apply inner.--multi-default-- args kwargs))))
+                  ((get inner.--multi-- dispatch-key) #* args #** kwargs)
+                  (inner.--multi-default-- #* args #** kwargs))))
   (setv inner.--multi-- {})
   (setv inner.--doc-- dispatch-fn.--doc--)
   (setv inner.--multi-default-- (fn [&rest args &kwargs kwargs] None))
diff --git a/hy/contrib/profile.hy b/hy/contrib/profile.hy
index afee3b0..42ef1a4 100644
--- a/hy/contrib/profile.hy
+++ b/hy/contrib/profile.hy
@@ -10,7 +10,7 @@
   `(do
      (import [pycallgraph [PyCallGraph]]
              [pycallgraph.output [GraphvizOutput]])
-     (with* [(apply PyCallGraph [] {"output" (GraphvizOutput)})]
+     (with* [(PyCallGraph :output (GraphvizOutput)))]
            ~@body)))
 
 
@@ -29,6 +29,6 @@
      (.disable ~g!hy-pr)
      (setv ~g!hy-s (StringIO))
      (setv ~g!hy-ps
-           (.sort-stats (apply pstats.Stats [~g!hy-pr] {"stream" ~g!hy-s})))
+           (.sort-stats (pstats.Stats ~g!hy-pr :stream ~g!hy-s)))
      (.print-stats ~g!hy-ps)
      (print (.getvalue ~g!hy-s))))
diff --git a/hy/core/language.hy b/hy/core/language.hy
index 6bcdb79..9c29d27 100644
--- a/hy/core/language.hy
+++ b/hy/core/language.hy
@@ -37,7 +37,7 @@
                 first-f (next rfs)
                 fs (tuple rfs))
           (fn [&rest args &kwargs kwargs]
-            (setv res (apply first-f args kwargs))
+            (setv res (first-f #* args #** kwargs))
             (for* [f fs]
               (setv res (f res)))
             res))))
@@ -45,7 +45,7 @@
 (defn complement [f]
   "Create a function that reverses truth value of another function"
   (fn [&rest args &kwargs kwargs]
-    (not (apply f args kwargs))))
+    (not (f #* args #** kwargs))))
 
 (defn cons [a b]
   "Return a fresh cons cell with car = a and cdr = b"
@@ -160,8 +160,8 @@
 (defn drop-last [n coll]
   "Return a sequence of all but the last n elements in coll."
   (setv iters (tee coll))
-  (map first (apply zip [(get iters 0)
-                         (drop n (get iters 1))])))
+  (map first (zip #* [(get iters 0)
+                      (drop n (get iters 1))])))
 
 (defn empty? [coll]
   "Return True if `coll` is empty"
@@ -250,7 +250,7 @@
 
 (defn interleave [&rest seqs]
   "Return an iterable of the first item in each of seqs, then the second etc."
-  (chain.from-iterable (apply zip seqs)))
+  (chain.from-iterable (zip #* seqs)))
 
 (defn interpose [item seq]
   "Return an iterable of the elements of seq separated by item"
@@ -275,7 +275,7 @@
    set of arguments and collects the results into a list."
   (setv fs (cons f fs))
   (fn [&rest args &kwargs kwargs]
-    (list-comp (apply f args kwargs) [f fs])))
+    (list-comp (f #* args #** kwargs) [f fs])))
 
 (defn last [coll]
   "Return last item from `coll`"
@@ -285,7 +285,7 @@
   "Return a dotted list construed from the elements of the argument"
   (if (not tl)
     hd
-    (cons hd (apply list* tl))))
+    (cons hd (list* #* tl))))
 
 (defn macroexpand [form]
   "Return the full macro expansion of form"
@@ -350,8 +350,8 @@
    slices (genexpr (islice (get coll-clones start) start None step)
                    [start (range n)]))
   (if (is fillvalue -sentinel)
-    (apply zip slices)
-    (apply zip-longest slices {"fillvalue" fillvalue})))
+    (zip #* slices)
+    (zip-longest #* slices :fillvalue fillvalue)))
 
 (defn pos? [n]
   "Return true if n is > 0"
diff --git a/hy/core/macros.hy b/hy/core/macros.hy
index 27eadf6..82cf3ae 100644
--- a/hy/core/macros.hy
+++ b/hy/core/macros.hy
@@ -207,7 +207,7 @@
   (setv retval (gensym))
   `(when (= --name-- "__main__")
      (import sys)
-     (setv ~retval (apply (fn [~@args] ~@body) sys.argv))
+     (setv ~retval ((fn [~@args] ~@body) #* sys.argv))
      (if (integer? ~retval)
        (sys.exit ~retval))))
 

From 97ecb0b5534c31c233b3ed17e74fb24148669520 Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Sat, 15 Jul 2017 16:54:43 -0700
Subject: [PATCH 3/6] Remove `apply` from tests

---
 tests/native_tests/contrib/multi.hy  |  6 ++---
 tests/native_tests/language.hy       | 40 ++++++----------------------
 tests/native_tests/native_macros.hy  |  4 +--
 tests/native_tests/operators.hy      |  5 ----
 tests/native_tests/py3_only_tests.hy |  9 +++----
 tests/native_tests/tag_macros.hy     |  5 ++--
 6 files changed, 19 insertions(+), 50 deletions(-)

diff --git a/tests/native_tests/contrib/multi.hy b/tests/native_tests/contrib/multi.hy
index 90c85dc..9b0294c 100644
--- a/tests/native_tests/contrib/multi.hy
+++ b/tests/native_tests/contrib/multi.hy
@@ -95,9 +95,9 @@
     ([&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")))
+  (assert (= (fun :a "t") "t"))
+  (assert (= (fun "hello " :b "world") "hello world"))
+  (assert (= (fun :a "hello " :b "world") "hello world")))
 
 
 (defn test-docs []
diff --git a/tests/native_tests/language.hy b/tests/native_tests/language.hy
index a284b39..51e221f 100644
--- a/tests/native_tests/language.hy
+++ b/tests/native_tests/language.hy
@@ -383,36 +383,12 @@
 
 (defn test-kwargs []
   "NATIVE: test kwargs things."
-  (assert (= (apply kwtest [] {"one" "two"}) {"one" "two"}))
+  (assert (= (kwtest :one "two") {"one" "two"}))
   (setv mydict {"one" "three"})
-  (assert (= (apply kwtest [] mydict) mydict))
-  (assert (= (apply kwtest [] ((fn [] {"one" "two"}))) {"one" "two"})))
+  (assert (= (kwtest #** mydict) mydict))
+  (assert (= (kwtest #** ((fn [] {"one" "two"}))) {"one" "two"})))
 
 
-(defn test-apply []
-  "NATIVE: test working with args and functions"
-  (defn sumit [a b c] (+ a b c))
-  (assert (= (apply sumit [1] {"b" 2 "c" 3}) 6))
-  (assert (= (apply sumit [1 2 2]) 5))
-  (assert (= (apply sumit [] {"a" 1 "b" 1 "c" 2}) 4))
-  (assert (= (apply sumit ((fn [] [1 1])) {"c" 1}) 3))
-  (defn noargs [] [1 2 3])
-  (assert (= (apply noargs) [1 2 3]))
-  (defn sumit-mangle [an-a a-b a-c a-d] (+ an-a a-b a-c a-d))
-  (def Z "a_d")
-  (assert (= (apply sumit-mangle [] {"an-a" 1 :a-b 2 'a-c 3 Z 4}) 10)))
-
-
-(defn test-apply-with-methods []
-  "NATIVE: test apply to call a method"
-  (setv str "foo {bar}")
-  (assert (= (apply .format [str] {"bar" "baz"})
-             (apply .format ["foo {0}" "baz"])
-             "foo baz"))
-  (setv lst ["a {0} {1} {foo} {bar}" "b" "c"])
-  (assert (= (apply .format lst {"foo" "d" "bar" "e"})
-             "a b c d e")))
-
 
 (defn test-dotted []
   "NATIVE: test dotted invocation"
@@ -430,20 +406,20 @@
   (assert (= (.meth m) "meth"))
   (assert (= (.meth m "foo" "bar") "meth foo bar"))
   (assert (= (.meth :b "1" :a "2" m "foo" "bar") "meth foo bar 2 1"))
-  (assert (= (apply .meth [m "foo" "bar"]) "meth foo bar"))
+  (assert (= (.meth m #* ["foo" "bar"]) "meth foo bar"))
 
   (setv x.p m)
   (assert (= (.p.meth x) "meth"))
   (assert (= (.p.meth x "foo" "bar") "meth foo bar"))
   (assert (= (.p.meth :b "1" :a "2" x "foo" "bar") "meth foo bar 2 1"))
-  (assert (= (apply .p.meth [x "foo" "bar"]) "meth foo bar"))
+  (assert (= (.p.meth x #* ["foo" "bar"]) "meth foo bar"))
 
   (setv x.a (X))
   (setv x.a.b m)
   (assert (= (.a.b.meth x) "meth"))
   (assert (= (.a.b.meth x "foo" "bar") "meth foo bar"))
   (assert (= (.a.b.meth :b "1" :a "2" x "foo" "bar") "meth foo bar 2 1"))
-  (assert (= (apply .a.b.meth [x "foo" "bar"]) "meth foo bar"))
+  (assert (= (.a.b.meth x #* ["foo" "bar"]) "meth foo bar"))
 
   (assert (is (.isdigit :foo) False)))
 
@@ -1185,8 +1161,8 @@
   "NATIVE: test &key function arguments"
   (defn foo [&key {"a" None "b" 1}] [a b])
   (assert (= (foo) [None 1]))
-  (assert (= (apply foo [] {"a" 2}) [2 1]))
-  (assert (= (apply foo [] {"b" 42}) [None 42])))
+  (assert (= (foo :a 2) [2 1]))
+  (assert (= (foo :b 42) [None 42])))
 
 
 (defn test-optional-arguments []
diff --git a/tests/native_tests/native_macros.hy b/tests/native_tests/native_macros.hy
index 3a0d428..d3efcb6 100644
--- a/tests/native_tests/native_macros.hy
+++ b/tests/native_tests/native_macros.hy
@@ -84,12 +84,12 @@
   "NATIVE: test macro calling a plain function"
   (assert (= 3 (bar 1 2))))
 
-(defn test-optional-and-apply-in-macro []
+(defn test-optional-and-unpacking-in-macro []
   ; https://github.com/hylang/hy/issues/1154
   (defn f [&rest args]
     (+ "f:" (repr args)))
   (defmacro mac [&optional x]
-   `(apply f [~x]))
+   `(f #* [~x]))
   (assert (= (mac) "f:(None,)")))
 
 (defn test-midtree-yield []
diff --git a/tests/native_tests/operators.hy b/tests/native_tests/operators.hy
index b49c754..be40cc5 100644
--- a/tests/native_tests/operators.hy
+++ b/tests/native_tests/operators.hy
@@ -288,8 +288,3 @@
   (assert (is (f 3 [1 2]) (!= f-name "in")))
   (assert (is (f 2 [1 2]) (= f-name "in")))
   (forbid (f 2 [1 2] [3 4])))
-
-#@(pytest.mark.xfail
-(defn test-apply-op []
-  ; https://github.com/hylang/hy/issues/647
-  (assert (= (eval '(apply + ["a" "b" "c"])) "abc"))))
diff --git a/tests/native_tests/py3_only_tests.hy b/tests/native_tests/py3_only_tests.hy
index b338ffa..84b8053 100644
--- a/tests/native_tests/py3_only_tests.hy
+++ b/tests/native_tests/py3_only_tests.hy
@@ -16,15 +16,15 @@
   "NATIVE: test keyword-only arguments"
   ;; keyword-only with default works
   (defn kwonly-foo-default-false [&kwonly [foo False]] foo)
-  (assert (= (apply kwonly-foo-default-false) False))
-  (assert (= (apply kwonly-foo-default-false [] {"foo" True}) True))
+  (assert (= (kwonly-foo-default-false) False))
+  (assert (= (kwonly-foo-default-false :foo True) True))
   ;; keyword-only without default ...
   (defn kwonly-foo-no-default [&kwonly foo] foo)
   (setv attempt-to-omit-default (try
                                 (kwonly-foo-no-default)
                                 (except [e [Exception]] e)))
   ;; works
-  (assert (= (apply kwonly-foo-no-default [] {"foo" "quux"}) "quux"))
+  (assert (= (kwonly-foo-no-default :foo "quux") "quux"))
   ;; raises TypeError with appropriate message if not supplied
   (assert (isinstance attempt-to-omit-default TypeError))
   (assert (in "missing 1 required keyword-only argument: 'foo'"
@@ -32,8 +32,7 @@
   ;; keyword-only with other arg types works
   (defn function-of-various-args [a b &rest args &kwonly foo &kwargs kwargs]
     (, a b args foo kwargs))
-  (assert (= (apply function-of-various-args
-                    [1 2 3 4] {"foo" 5 "bar" 6 "quux" 7})
+  (assert (= (function-of-various-args 1 2 3 4 :foo 5 :bar 6 :quux 7)
              (, 1 2 (, 3 4)  5 {"bar" 6 "quux" 7}))))
 
 
diff --git a/tests/native_tests/tag_macros.hy b/tests/native_tests/tag_macros.hy
index ba586f6..18beaa7 100644
--- a/tests/native_tests/tag_macros.hy
+++ b/tests/native_tests/tag_macros.hy
@@ -100,9 +100,8 @@
     "Increments each argument passed to the decorated function."
     ((wraps func)
        (fn [&rest args &kwargs kwargs]
-         (apply func
-                (map inc args)
-                (dict-comp k (inc v) [[k v] (.items kwargs)])))))
+         (func #* (map inc args)
+               #** (dict-comp k (inc v) [[k v] (.items kwargs)])))))
 
   #@(increment-arguments
      (defn foo [&rest args &kwargs kwargs]

From 784a44601b63357d28ff150d072bf90a524f9432 Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Wed, 19 Jul 2017 10:18:55 -0700
Subject: [PATCH 4/6] Remove the implementation of `apply`

---
 NEWS           |   2 +
 hy/compiler.py | 109 -------------------------------------------------
 2 files changed, 2 insertions(+), 109 deletions(-)

diff --git a/NEWS b/NEWS
index fe7ffb9..3bae0ca 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,8 @@ Changes from 0.13.0
 
    [ Language Changes ]
    * `yield-from` is no longer supported under Python 2
+   * `apply` has been replaced with Python-style unpacking operators `#*` and
+     `#**` (e.g., `(f #* args #** kwargs)`)
    * Single-character "sharp macros" changed to "tag macros", which can have
      longer names
    * Periods are no longer allowed in keywords
diff --git a/hy/compiler.py b/hy/compiler.py
index 97a4c73..5fd073f 100755
--- a/hy/compiler.py
+++ b/hy/compiler.py
@@ -1587,115 +1587,6 @@ class HyASTCompiler(object):
             generators=expr.generators)
         return ret
 
-    @builds("apply")
-    @checkargs(min=1, max=3)
-    def compile_apply_expression(self, expr):
-        expr.pop(0)  # apply
-
-        ret = Result()
-
-        fun = expr.pop(0)
-
-        # We actually defer the compilation of the function call to
-        # @builds(HyExpression), allowing us to work on method calls
-        call = HyExpression([fun]).replace(fun)
-
-        if isinstance(fun, HySymbol) and fun.startswith("."):
-            # (apply .foo lst) needs to work as lst[0].foo(*lst[1:])
-            if not expr:
-                raise HyTypeError(
-                    expr, "apply of a method needs to have an argument"
-                )
-
-            # We need to grab the arguments, and split them.
-
-            # Assign them to a variable if they're not one already
-            if type(expr[0]) == HyList:
-                if len(expr[0]) == 0:
-                    raise HyTypeError(
-                        expr, "apply of a method needs to have an argument"
-                    )
-                call.append(expr[0].pop(0))
-            else:
-                if isinstance(expr[0], HySymbol):
-                    tempvar = expr[0]
-                else:
-                    tempvar = HySymbol(self.get_anon_var()).replace(expr[0])
-                    assignment = HyExpression(
-                        [HySymbol("setv"), tempvar, expr[0]]
-                    ).replace(expr[0])
-
-                    # and add the assignment to our result
-                    ret += self.compile(assignment)
-
-                # The first argument is the object on which to call the method
-                # So we translate (apply .foo args) to (.foo (get args 0))
-                call.append(HyExpression(
-                    [HySymbol("get"), tempvar, HyInteger(0)]
-                ).replace(tempvar))
-
-                # We then pass the other arguments to the function
-                expr[0] = HyExpression(
-                    [HySymbol("cut"), tempvar, HyInteger(1)]
-                ).replace(expr[0])
-
-        ret += self.compile(call)
-
-        if not isinstance(ret.expr, ast.Call):
-            raise HyTypeError(
-                fun, "compiling the application of `{}' didn't return a "
-                "function call, but `{}'".format(fun, type(ret.expr).__name__)
-            )
-        if ret.expr.starargs or ret.expr.kwargs:
-            raise HyTypeError(
-                expr, "compiling the function application returned a function "
-                "call with arguments"
-            )
-
-        if expr:
-            stargs = expr.pop(0)
-            if stargs is not None:
-                stargs = self.compile(stargs)
-                if PY35:
-                    stargs_expr = stargs.force_expr
-                    ret.expr.args.append(
-                        ast.Starred(stargs_expr, ast.Load(),
-                                    lineno=stargs_expr.lineno,
-                                    col_offset=stargs_expr.col_offset)
-                    )
-                else:
-                    ret.expr.starargs = stargs.force_expr
-                ret = stargs + ret
-
-        if expr:
-            kwargs = expr.pop(0)
-            if isinstance(kwargs, HyDict):
-                new_kwargs = []
-                for k, v in kwargs.items():
-                    if isinstance(k, HySymbol):
-                        pass
-                    elif isinstance(k, HyString):
-                        k = HyString(hy_symbol_mangle(str_type(k))).replace(k)
-                    elif isinstance(k, HyKeyword):
-                        sym = hy_symbol_mangle(str_type(k)[2:])
-                        k = HyString(sym).replace(k)
-                    new_kwargs += [k, v]
-                kwargs = HyDict(new_kwargs).replace(kwargs)
-
-            kwargs = self.compile(kwargs)
-            if PY35:
-                kwargs_expr = kwargs.force_expr
-                ret.expr.keywords.append(
-                    ast.keyword(None, kwargs_expr,
-                                lineno=kwargs_expr.lineno,
-                                col_offset=kwargs_expr.col_offset)
-                )
-            else:
-                ret.expr.kwargs = kwargs.force_expr
-            ret = kwargs + ret
-
-        return ret
-
     @builds("not")
     @builds("~")
     @checkargs(1)

From 0bbb5f8e34abd643bcd2fbf970ab66c42ec21eef Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Wed, 19 Jul 2017 10:25:24 -0700
Subject: [PATCH 5/6] hy-repr: Support #* and #**

---
 hy/contrib/hy_repr.hy                 | 4 ++++
 tests/native_tests/contrib/hy_repr.hy | 7 ++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/hy/contrib/hy_repr.hy b/hy/contrib/hy_repr.hy
index 2053504..ea67efc 100644
--- a/hy/contrib/hy_repr.hy
+++ b/hy/contrib/hy_repr.hy
@@ -37,6 +37,10 @@
               (+ "~" (f (second x) q))
             (= (first x) 'unquote_splice)
               (+ "~@" (f (second x) q))
+            (= (first x) 'unpack_iterable)
+              (+ "#* " (f (second x) q))
+            (= (first x) 'unpack_mapping)
+              (+ "#** " (f (second x) q))
             ; else
               (+ "(" (catted) ")"))
           (+ "(" (catted) ")"))
diff --git a/tests/native_tests/contrib/hy_repr.hy b/tests/native_tests/contrib/hy_repr.hy
index 9bbdd09..a9c0475 100644
--- a/tests/native_tests/contrib/hy_repr.hy
+++ b/tests/native_tests/contrib/hy_repr.hy
@@ -28,8 +28,8 @@
     [1 2 3] (, 1 2 3) #{1 2 3} (frozenset #{1 2 3})
     '[1 2 3] '(, 1 2 3) '#{1 2 3} '(frozenset #{1 2 3})
     {"a" 1 "b" 2 "a" 3} '{"a" 1 "b" 2 "a" 3}
-    [1 [2 3] (, 4 (, 'mysymbol :mykeyword)) {"a" b"hello"}]
-    '[1 [2 3] (, 4 (, mysymbol :mykeyword)) {"a" b"hello"}]])
+    [1 [2 3] (, 4 (, 'mysymbol :mykeyword)) {"a" b"hello"} '(f #* a #** b)]
+    '[1 [2 3] (, 4 (, mysymbol :mykeyword)) {"a" b"hello"} (f #* a #** b)]])
   (for [original-val values]
     (setv evaled (eval (read-str (hy-repr original-val))))
     (assert (= evaled original-val))
@@ -59,7 +59,8 @@
     "{1 20}"
     "'{1 10 1 20}"
     "'asymbol"
-    ":akeyword"])
+    ":akeyword"
+    "'(f #* args #** kwargs)"])
   (for [original-str strs]
     (setv rep (hy-repr (eval (read-str original-str))))
     (assert (= rep original-str))))

From 3f3cce8785c8d11c711d6429a472bbe646512a35 Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Wed, 19 Jul 2017 11:00:43 -0700
Subject: [PATCH 6/6] Update docs: `apply` is gone; #* and #** are in

---
 docs/language/api.rst  | 96 +++++++++++++++++++++++-------------------
 docs/language/core.rst |  4 +-
 docs/tutorial.rst      | 19 +++------
 3 files changed, 59 insertions(+), 60 deletions(-)

diff --git a/docs/language/api.rst b/docs/language/api.rst
index 5241b3a..3904e86 100644
--- a/docs/language/api.rst
+++ b/docs/language/api.rst
@@ -154,41 +154,6 @@ it appends it as the last argument. The following code demonstrates this:
     5 10
 
 
-apply
------
-
-``apply`` is used to apply an optional list of arguments and an
-optional dictionary of kwargs to a function. The symbol mangling
-transformations will be applied to all keys in the dictionary of
-kwargs, provided the dictionary and its keys are defined in-place.
-
-Usage: ``(apply fn-name [args] [kwargs])``
-
-Examples:
-
-.. code-block:: clj
-
-    (defn thunk []
-      "hy there")
-
-    (apply thunk)
-    ;=> "hy there"
-
-    (defn total-purchase [price amount &optional [fees 1.05] [vat 1.1]]
-      (* price amount fees vat))
-
-    (apply total-purchase [10 15])
-    ;=> 173.25
-
-    (apply total-purchase [10 15] {"vat" 1.05})
-    ;=> 165.375
-
-    (apply total-purchase [] {"price" 10 "amount" 15 "vat" 1.05})
-    ;=> 165.375
-
-    (apply total-purchase [] {:price 10 :amount 15 :vat 1.05})
-    ;=> 165.375
-
 and
 ---
 
@@ -596,8 +561,8 @@ Parameters may have the following keywords in front of them:
         parameter_1 1
         parameter_2 2
 
-        ; to avoid the mangling of '-' to '_', use apply:
-        => (apply print-parameters [] {"parameter-1" 1 "parameter-2" 2})
+        ; to avoid the mangling of '-' to '_', use unpacking:
+        => (print-parameters #** {"parameter-1" 1 "parameter-2" 2})
         parameter-1 1
         parameter-2 2
 
@@ -634,19 +599,19 @@ Parameters may have the following keywords in front of them:
 
     .. code-block:: clj
 
-        => (defn compare [a b &kwonly keyfn [reverse false]]
+        => (defn compare [a b &kwonly keyfn [reverse False]]
         ...  (setv result (keyfn a b))
         ...  (if (not reverse)
         ...    result
         ...    (- result)))
-        => (apply compare ["lisp" "python"]
-        ...        {"keyfn" (fn [x y]
-        ...                   (reduce - (map (fn [s] (ord (first s))) [x y])))})
+        => (compare "lisp" "python"
+        ...         :keyfn (fn [x y]
+        ...                  (reduce - (map (fn [s] (ord (first s))) [x y]))))
         -4
-        => (apply compare ["lisp" "python"]
-        ...        {"keyfn" (fn [x y]
+        => (compare "lisp" "python"
+        ...         :keyfn (fn [x y]
         ...                   (reduce - (map (fn [s] (ord (first s))) [x y])))
-        ...         "reverse" True})
+        ...         :reverse True)
         4
 
     .. code-block:: python
@@ -1576,6 +1541,49 @@ the given conditional is ``False``. The following shows the expansion of this ma
       (do statement))
 
 
+unpack-iterable, unpack-mapping
+-------------------------------
+
+``unpack-iterable`` and ``unpack-mapping`` allow an iterable or mapping
+object (respectively) to provide positional or keywords arguments
+(respectively) to a function.
+
+.. code-block:: clj
+
+    => (defn f [a b c d] [a b c d])
+    => (f (unpack-iterable [1 2]) (unpack-mapping {"c" 3 "d" 4}))
+    [1, 2, 3, 4]
+
+``unpack-iterable`` is usually written with the shorthand ``#*``, and
+``unpack-mapping`` with ``#**``.
+
+.. code-block:: clj
+
+    => (f #* [1 2] #** {"c" 3 "d" 4})
+    [1, 2, 3, 4]
+
+With Python 3, you can unpack in an assignment list (:pep:`3132`).
+
+.. code-block:: clj
+
+    => (setv [a #* b c] [1 2 3 4 5])
+    => [a b c]
+    [1, [2, 3, 4], 5]
+
+With Python 3.5 or greater, unpacking is allowed in more contexts than just
+function calls, and you can unpack more than once in the same expression
+(:pep:`448`).
+
+.. code-block:: clj
+
+    => [#* [1 2] #* [3 4]]
+    [1, 2, 3, 4]
+    => {#** {1 2} #** {3 4}}
+    {1: 2, 3: 4}
+    => (f #* [1] #* [2] #** {"c" 3} #** {"d" 4})
+    [1, 2, 3, 4]
+
+
 unquote
 -------
 
diff --git a/docs/language/core.rst b/docs/language/core.rst
index 21c111b..4983af9 100644
--- a/docs/language/core.rst
+++ b/docs/language/core.rst
@@ -1216,9 +1216,9 @@ if *from-file* ends before a complete expression can be parsed.
 
    => (import io)
    => (def buffer (io.StringIO "(+ 2 2)\n(- 2 1)"))
-   => (eval (apply read [] {"from_file" buffer}))
+   => (eval (read :from_file buffer))
    4
-   => (eval (apply read [] {"from_file" buffer}))
+   => (eval (read :from_file buffer))
    1
 
    => ; assuming "example.hy" contains:
diff --git a/docs/tutorial.rst b/docs/tutorial.rst
index ceeab77..3883abe 100644
--- a/docs/tutorial.rst
+++ b/docs/tutorial.rst
@@ -423,8 +423,7 @@ The same thing in Hy::
   => (optional-arg 1 2 3 4)
   [1 2 3 4]
 
-If you're running a version of Hy past 0.10.1 (eg, git master),
-there's also a nice new keyword argument syntax::
+You can call keyword arguments like this::
 
   => (optional-arg :keyword1 1
   ...              :pos2 2
@@ -432,21 +431,13 @@ there's also a nice new keyword argument syntax::
   ...              :keyword2 4)
   [3, 2, 1, 4]
 
-Otherwise, you can always use `apply`.  But what's `apply`?
-
-Are you familiar with passing in `*args` and `**kwargs` in Python?::
-
-  >>> args = [1 2]
-  >>> kwargs = {"keyword2": 3
-  ...           "keyword1": 4}
-  >>> optional_arg(*args, **kwargs)
-
-We can reproduce this with `apply`::
+You can unpack arguments with the syntax ``#* args`` and ``#** kwargs``,
+similar to `*args` and `**kwargs` in Python::
 
   => (setv args [1 2])
   => (setv kwargs {"keyword2" 3
   ...              "keyword1" 4})
-  => (apply optional-arg args kwargs)
+  => (optional-arg #* args #** kwargs)
   [1, 2, 4, 3]
 
 There's also a dictionary-style keyword arguments construction that
@@ -460,7 +451,7 @@ looks like:
 The difference here is that since it's a dictionary, you can't rely on
 any specific ordering to the arguments.
 
-Hy also supports ``*args`` and ``**kwargs``.  In Python::
+Hy also supports ``*args`` and ``**kwargs`` in parameter lists.  In Python::
 
   def some_func(foo, bar, *args, **kwargs):
     import pprint