Use __future__.division for all Hy code

Fixes #106
Note: This is implemented by replacing all calls to Python's
builtin "compile" function by calls to hy.importer.compile_,
which adds the "future division" flag. Anyone using "compile"
in future work will have to remember this.

bin/hy

@@ -21,6 +21,7 @@ from hy.lex.states import Idle, LexException
 from hy.lex.machine import Machine
 from hy.compiler import hy_compile
 from hy.core import process
+from hy.importer import compile_
 
 import hy.completer
 
@@ -58,7 +59,7 @@ class HyREPL(code.InteractiveConsole):
         _machine = Machine(Idle, 1, 0)
         try:
             _ast = hy_compile(tokens, root=ast.Interactive)
-            code = compile(_ast, filename, symbol)
+            code = compile_(_ast, filename, symbol)
         except Exception:
             self.showtraceback()
             return False

hy/importer.py

@@ -31,7 +31,7 @@ import imp
 import sys
 import ast
 import os
-
+import __future__
 
 if sys.version_info[0] >= 3:
     from io import StringIO
@@ -39,6 +39,10 @@ else:
     from StringIO import StringIO  # NOQA
 
 
+def compile_(ast, filename, mode):
+    return compile(ast, filename, mode, __future__.CO_FUTURE_DIVISION)
+
+
 def import_buffer_to_hst(fd):
     tree = tokenize(fd.read() + "\n")
     tree = process(tree)
@@ -65,7 +69,7 @@ def import_file_to_module(name, fpath):
     _ast = import_file_to_ast(fpath)
     mod = imp.new_module(name)
     mod.__file__ = fpath
-    eval(compile(_ast, fpath, "exec"), mod.__dict__)
+    eval(compile_(_ast, fpath, "exec"), mod.__dict__)
     return mod
 
 
@@ -77,7 +81,7 @@ def hy_eval(hytree, namespace):
     foo.end_column = 0
     hytree.replace(foo)
     _ast = hy_compile(hytree, root=ast.Expression)
-    return eval(compile(_ast, "<eval>", "eval"), namespace)
+    return eval(compile_(_ast, "<eval>", "eval"), namespace)
 
 
 def write_hy_as_pyc(fname):
@@ -88,7 +92,7 @@ def write_hy_as_pyc(fname):
             timestamp = long(os.stat(fname).st_mtime)
 
     _ast = import_file_to_ast(fname)
-    code = compile(_ast, fname, "exec")
+    code = compile_(_ast, fname, "exec")
     cfile = "%s.pyc" % fname[:-len(".hy")]
 
     with open(cfile, 'wb') as fc:

tests/native_tests/math.hy

@@ -27,7 +27,10 @@
 
 (setv test_div (fn []
   "NATIVE: Test division"
-  (assert (= 25 (/ 100 2 2)))))
+  (assert (= 25 (/ 100 2 2)))
+  ; Commented out until float constants get implemented
+  ; (assert (= 0.5 (/ 1 2)))
+  (assert (= 1 (* 2 (/ 1 2))))))
 
 (setv test_int_div (fn []
   "NATIVE: Test integer division"