From: Benjamin Peterson <benjamin@python.org>
Date: Wed, 6 Sep 2017 01:18:16 +0000 (-0700)
Subject: [2.7] Issue GH-28705: greatly simplify the FAQ entry on transpiling. (#3371)
X-Git-Tag: v2.7.15rc1~219
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6d6ff08d38bec7e3f844079c681bafad16e1d6e1;p=python

[2.7] Issue GH-28705: greatly simplify the FAQ entry on transpiling. (#3371)

This also eliminats a dead link to Weave in the process..
(cherry picked from commit 78ffd6cffacb04bea61bb0ef850d05859ab2dbe4)
---

diff --git a/Doc/faq/design.rst b/Doc/faq/design.rst
index 0a8cfdd25d..15e4af57fe 100644
--- a/Doc/faq/design.rst
+++ b/Doc/faq/design.rst
@@ -391,50 +391,11 @@ is exactly the same type of object that a lambda expression yields) is assigned!
 Can Python be compiled to machine code, C or some other language?
 -----------------------------------------------------------------
 
-Not easily.  Python's high level data types, dynamic typing of objects and
-run-time invocation of the interpreter (using :func:`eval` or :keyword:`exec`)
-together mean that a "compiled" Python program would probably consist mostly of
-calls into the Python run-time system, even for seemingly simple operations like
-``x+1``.
-
-Several projects described in the Python newsgroup or at past `Python
-conferences <https://www.python.org/community/workshops/>`_ have shown that this
-approach is feasible, although the speedups reached so far are only modest
-(e.g. 2x).  Jython uses the same strategy for compiling to Java bytecode.  (Jim
-Hugunin has demonstrated that in combination with whole-program analysis,
-speedups of 1000x are feasible for small demo programs.  See the proceedings
-from the `1997 Python conference
-<http://legacy.python.org/workshops/1997-10/proceedings/>`_ for more information.)
-
-Internally, Python source code is always translated into a bytecode
-representation, and this bytecode is then executed by the Python virtual
-machine.  In order to avoid the overhead of repeatedly parsing and translating
-modules that rarely change, this byte code is written into a file whose name
-ends in ".pyc" whenever a module is parsed.  When the corresponding .py file is
-changed, it is parsed and translated again and the .pyc file is rewritten.
-
-There is no performance difference once the .pyc file has been loaded, as the
-bytecode read from the .pyc file is exactly the same as the bytecode created by
-direct translation.  The only difference is that loading code from a .pyc file
-is faster than parsing and translating a .py file, so the presence of
-precompiled .pyc files improves the start-up time of Python scripts.  If
-desired, the Lib/compileall.py module can be used to create valid .pyc files for
-a given set of modules.
-
-Note that the main script executed by Python, even if its filename ends in .py,
-is not compiled to a .pyc file.  It is compiled to bytecode, but the bytecode is
-not saved to a file.  Usually main scripts are quite short, so this doesn't cost
-much speed.
-
-.. XXX check which of these projects are still alive
-
-There are also several programs which make it easier to intermingle Python and C
-code in various ways to increase performance.  See, for example, `Cython <http://cython.org/>`_ , `Psyco
-<http://psyco.sourceforge.net/>`_, `Pyrex
-<https://www.cosc.canterbury.ac.nz/~greg/python/Pyrex/>`_, `PyInline
-<http://pyinline.sourceforge.net/>`_, `Py2Cmod
-<http://sourceforge.net/projects/py2cmod/>`_, and
-`Weave <https://docs.scipy.org/doc/scipy-dev/reference/tutorial/weave.html>`_.
+`Cython <http://cython.org/>`_ compiles a modified version of Python with
+optional annotations into C extensions.  `Nuitka <http://www.nuitka.net/>`_ is
+an up-and-coming compiler of Python into C++ code, aiming to support the full
+Python language. For compiling to Java you can consider
+`VOC <https://voc.readthedocs.io>`_.
 
 
 How does Python manage memory?