add information about alternate implementations, noting that documentation

for the implementation should be consulted
(thanks to Evelyn Mitchell for suggesting this)
This commit is contained in:
Fred Drake 2005-07-20 04:33:01 +00:00
parent d5ecb513ad
commit 21c825417f

View file

@ -21,7 +21,7 @@ It is dangerous to add too many implementation details to a language
reference document --- the implementation may change, and other
implementations of the same language may work differently. On the
other hand, there is currently only one Python implementation in
widespread use (although a second one now exists!), and
widespread use (although alternate implementations exist), and
its particular quirks are sometimes worth being mentioned, especially
where the implementation imposes additional limitations. Therefore,
you'll find short ``implementation notes'' sprinkled throughout the
@ -34,6 +34,56 @@ built-in modules are mentioned when they interact in a significant way
with the language definition.
\section{Alternate Implementations\label{implementations}}
Though there is one Python implementation which is by far the most
popular, there are some alternate implementations which are of
particular interest to different audiences.
Known implementations include:
\begin{itemize}
\item[CPython]
This is the original and most-maintained implementation of Python,
written in C. New language features generally appear here first.
\item[Jython]
Python implemented in Java. This implementation can be used as a
scripting language for Java applications, or can be used to create
applications using the Java class libraries. It is also often used to
create tests for Java libraries. More information can be found at
\ulink{the Jython website}{http://www.jython.org/}.
\item[Python for .NET]
This implementation actually uses the CPython implementation, but is a
managed .NET application and makes .NET libraries available. This was
created by Brian Lloyd. For more information, see the \ulink{Python
for .NET home page}{http://www.zope.org/Members/Brian/PythonNet}.
\item[IronPython]
An alternate Python for\ .NET. Unlike Python.NET, this is a complete
Python implementation that generates IL, and compiles Python code
directly to\ .NET assemblies. It was created by Jim Hugunin, the
original creator of Jython. For more information, see \ulink{the
IronPython website}{http://workspaces.gotdotnet.com/ironpython}.
\item[PyPy]
An implementation of Python written in Python; even the bytecode
interpreter is written in Python. This is executed using CPython as
the underlying interpreter. One of the goals of the project is to
encourage experimentation with the language itself by making it easier
to modify the interpreter (since it is written in Python). Additional
information is available on \ulink{the PyPy project's home
page}{http://codespeak.net/pypy/}.
\end{itemize}
Each of these implementations varies in some way from the language as
documented in this manual, or introduces specific information beyond
what's covered in the standard Python documentation. Please refer to
the implementation-specific documentation to determine what else you
need to know about the specific implementation you're using.
\section{Notation\label{notation}}
The descriptions of lexical analysis and syntax use a modified BNF