macropy3 1.1.0b1

.. -*- coding: utf-8 -*-

=============================
MacroPy3 1.1.0 (unreleased)
=============================

.. image:: https://travis-ci.org/azazel75/macropy.svg?branch=master
:target: https://travis-ci.org/azazel75/macropy

**MacroPy** is an implementation of `Syntactic Macros
<http://tinyurl.com/cmlls8v>`_ in the `Python Programming Language
<http://python.org/>`_. MacroPy provides a mechanism for user-defined
functions (macros) to perform transformations on the `abstract syntax
tree <http://en.wikipedia.org/wiki/Abstract_syntax_tree>`_ (AST) of a
Python program at *import time*. This is an easy way to enhance the
semantics of a Python program in ways which are otherwise impossible,
for example providing an extremely concise way of declaring classes.

Python like you've never seen before
====================================

MacroPy allows you to create constructs which are impossible to have
in normal python code, such as:

Tracing
-------

.. code:: python

with trace:
sum([x + 5 for x in range(3)])

# sum([x + 5 for x in range(3)])
# range(3) -> [0, 1, 2]
# x + 5 -> 5
# x + 5 -> 6
# x + 5 -> 7
# [x + 5 for x in range(3)] -> [5, 6, 7]
# sum([x + 5 for x in range(3)]) -> 18

Quick Lambdas
-------------

.. code:: python

print(list(map(f[_[0]], ['omg', 'wtf', 'bbq'])))
# ['o', 'w', 'b']

print(list(reduce(f[_ + _], ['omg', 'wtf', 'bbq'])))
# 'omgwtfbbq

Case Classes
------------

.. code:: python

@case
class Point(x, y): pass

p = Point(1, 2)

print str(p) #Point(1, 2)
print p.x #1
print p.y #2
print Point(1, 2) == Point(1, 2) # True

and more! See the docs at
`<http://macropy3.readthedocs.io/en/latest/>`_.

Requirements
============

MacroPy3 is tested to run on `CPython 3.4
<http://en.wikipedia.org/wiki/CPython>`_ or newer and `PyPy
<http://pypy.org/>`_ 3.5. I has no current support for `Jython
<http://www.jython.org/>`_. MacroPy3 is also available on `PyPI
<https://pypi.python.org/pypi/macropy3>`_.

Installation
============

Just execute a:

.. code:: console

$ pip install macropy3

if you want to use macros that require external libraries in order to
work, you can automatically install those dependencies by installing
one of the ``pinq`` or ``pyxl`` extras like this:

.. code:: console

$ pip install macropy3[pinq,pyxl]


then have a look at the docs at `<http://macropy3.readthedocs.io/en/latest/>`_.

How to contribute
=================

We're open to contributions, so send us your
ideas/questions/issues/pull-requests and we'll do our best to
accommodate you! You can ask questions on the `Google Group
<https://groups.google.com/forum/#!forum/macropy>`_ and on the
`Gitter channel <https://gitter.im/lihaoyi/macropy>`_ or file bugs on
thee `issues`__ page. See the `changelist <CHANGES.rst>`:repo: to
see what's changed recently.

__ https://github.com/lihaoyi/macropy/issues

Credits
=======

MacroPy was initially created as a final project for the `MIT
<http://web.mit.edu/>`_ class `6.945: Adventures in Advanced Symbolic
Programming <http://groups.csail.mit.edu/mac/users/gjs/6.945/>`_,
taught by `Gerald Jay Sussman
<http://groups.csail.mit.edu/mac/users/gjs/>`_ and `Pavel Panchekha
<http://pavpanchekha.com/>`_. Inspiration was taken from project such
as `Scala Macros <http://scalamacros.org/>`_, `Karnickel
<https://pypi.python.org/pypi/karnickel>`_ and `Pyxl
<https://github.com/dropbox/pyxl>`_.

The MIT License (MIT)

Copyright (c) 2013-2018, `Li Haoyi <https://github.com/lihaoyi>`_, `Justin
Holmgren <https://github.com/jnhnum1>`_, `Alberto Berti
<https://github.com/azazel75>`_ and all the other contributors

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.

Changelog
=========

1.1.0 (unreleased)
-----------------------

1.1.0b1 (2018-05-12)
-----------------------

- Fix and re-enable the ``SaveExporter()`` class.

- Fix some issues with pattern matching module requiring non obvious
imports from user's side.

- Fix pattern matching macro need to import ``_matching`` symbol

- Add an ``OptionalMatcher`` to pattern matching macro to support
exclusive or conditions.

- Refactor documentation using sphinx.

- Refactor the macro expansion core code. Now the macro expansion
order is from inside-out. This allows to use macros inside other
macro's body.

- Added support for Python 3.4.

- Added ``SELECT * FROM country`` emulation in `pinq` macro.

- Update the examples.

- Update tco and pyxl macros.

- Prevent the import hooks from raising errors.


1.0.4.dev2 (2017-09-08)
-----------------------

- Add MANIFEST.in;

1.0.4.dev1 (2017-09-08)
-----------------------

- Updated the import machinery and macro detection to be compatible
with Python 3.5+.

- Removed support for Python 2, supporting it would require a way to
manage differences at the ast level, but i don't use Python2 anymore.

- Added support for Python 3.5+ in the form of new call arguments form
and new ``AsyncFunctionDef``.

- Basic scope analysis now available in the form of the ``@Scoped``
decorator, to be used in conjunction with ``@Walker``.

1.0.3
-----

- Error messages are now raised at run-time rather than at import
time, with other improvements (double stack traces, catchability).

- ``@enum`` macro now has much better error messages

- Improved error messages for mis-use of stub functions outside their
related macro (e.g. the ``u``, ``name``, ``ast`` stubs for the ``q``/``hq``
macros)

- Improved error messages for invalid case class signatures

- Hygienic Quasiquotes now allow lexical capture of module objects

1.0.2
-----

- Removed unit test from PyPI distribution

1.0.1
-----
- Fixed a bug in ``ast_ctx_fixer``
- ``gen_sym()`` is now ``gen_sym(name="sym")``, allowing you to override the base name
- Implemented ``macropy.case_classes.enum`` macro
- Implemented ``macropy.quick_lambda.lazy`` and ``macropy.quick_lambda.interned`` macros