Merged revisions 63829-63831,63858,63865,63879,63882,63948,63970-63972,63976,63989,64014-64015,64021-64022,64063-64065,64067 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r63829 | mark.summerfield | 2008-05-31 15:05:34 +0200 (Sat, 31 May 2008) | 4 lines

  Added a note to [] that special forms & special chars lose their meaning
  and backrefs can't be used inside []
........
  r63830 | georg.brandl | 2008-05-31 16:40:09 +0200 (Sat, 31 May 2008) | 2 lines

  #3010: clarification about stdin/use_rawinput.
........
  r63831 | georg.brandl | 2008-05-31 16:45:55 +0200 (Sat, 31 May 2008) | 2 lines

  #3005: add explaining sentence to easydialogs docs.
........
  r63858 | georg.brandl | 2008-06-01 18:41:31 +0200 (Sun, 01 Jun 2008) | 2 lines

  Add plain text make target.
........
  r63865 | georg.brandl | 2008-06-01 21:24:36 +0200 (Sun, 01 Jun 2008) | 2 lines

  Spaces vs. tabs.
........
  r63879 | gregory.p.smith | 2008-06-02 00:57:47 +0200 (Mon, 02 Jun 2008) | 3 lines

  Make the _H #define's match the header file names.  Fix comments to
  mention the correct type names.
........
  r63882 | gregory.p.smith | 2008-06-02 01:48:47 +0200 (Mon, 02 Jun 2008) | 3 lines

  Adds a Thread.getIdent() method to provide the _get_ident() value for
  any given threading.Thread object.  feature request issue 2871.
........
  r63948 | alexandre.vassalotti | 2008-06-04 22:41:44 +0200 (Wed, 04 Jun 2008) | 2 lines

  Fixed complex.__getnewargs__() to not emit another complex object.
........
  r63970 | andrew.kuchling | 2008-06-06 01:33:54 +0200 (Fri, 06 Jun 2008) | 1 line

  Document 'utc' parameter
........
  r63971 | andrew.kuchling | 2008-06-06 01:35:31 +0200 (Fri, 06 Jun 2008) | 1 line

  Add various items
........
  r63972 | andrew.kuchling | 2008-06-06 01:35:48 +0200 (Fri, 06 Jun 2008) | 1 line

  Grammar fix
........
  r63976 | georg.brandl | 2008-06-06 09:34:50 +0200 (Fri, 06 Jun 2008) | 2 lines

  Markup fix.
........
  r63989 | thomas.heller | 2008-06-06 20:42:11 +0200 (Fri, 06 Jun 2008) | 2 lines

  Add a reminder for the maintainer of whatsnew.
........
  r64014 | georg.brandl | 2008-06-07 17:59:10 +0200 (Sat, 07 Jun 2008) | 3 lines

  Factor out docstring dedenting from inspect.getdoc() into inspect.cleandoc()
  to ease standalone use of the algorithm.
........
  r64015 | georg.brandl | 2008-06-07 18:04:01 +0200 (Sat, 07 Jun 2008) | 2 lines

  Revert unwanted changes.
........
  r64021 | georg.brandl | 2008-06-07 20:16:12 +0200 (Sat, 07 Jun 2008) | 2 lines

  X-ref to numbers module.
........
  r64022 | georg.brandl | 2008-06-07 20:17:37 +0200 (Sat, 07 Jun 2008) | 3 lines

  Document the "st" API, to avoid confusion with the "new" AST.
  Add a note about using the new AST module.
........
  r64063 | martin.v.loewis | 2008-06-10 07:03:35 +0200 (Tue, 10 Jun 2008) | 2 lines

  Add Gregor Lingl.
........
  r64064 | georg.brandl | 2008-06-10 09:45:28 +0200 (Tue, 10 Jun 2008) | 2 lines

  Add the "ast" module, containing helpers to ease use of the "_ast" classes.
........
  r64065 | raymond.hettinger | 2008-06-10 09:57:15 +0200 (Tue, 10 Jun 2008) | 1 line

  Add Arnaud for his efforts on multi-arg set operations.
........
  r64067 | georg.brandl | 2008-06-10 14:46:39 +0200 (Tue, 10 Jun 2008) | 2 lines

  #2536: fix itertools.permutations and itertools.combinations docstrings.
........

1 files changed, 257 insertions, 0 deletions

diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
new file mode 100644
index 0000000..70840da
--- /dev/null
+++ b/Doc/library/ast.rst
@@ -0,0 +1,257 @@
+.. _ast:
+
+Abstract Syntax Trees
+=====================
+
+.. module:: ast
+   :synopsis: Abstract Syntax Tree classes and manipulation.
+
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+.. sectionauthor:: Georg Brandl <georg@python.org>
+
+.. versionadded:: 2.5
+   The low-level ``_ast`` module containing only the node classes.
+
+.. versionadded:: 2.6
+   The high-level ``ast`` module containing all helpers.
+
+
+The :mod:`ast` module helps Python applications to process trees of the Python
+abstract syntax grammar.  The abstract syntax itself might change with each
+Python release; this module helps to find out programmatically what the current
+grammar looks like.
+
+An abstract syntax tree can be generated by passing :data:`_ast.PyCF_ONLY_AST`
+as a flag to the :func:`compile` builtin function, or using the :func:`parse`
+helper provided in this module.  The result will be a tree of objects whose
+classes all inherit from :class:`ast.AST`.
+
+A modified abstract syntax tree can be compiled into a Python code object using
+the built-in :func:`compile` function.
+
+Node classes
+------------
+
+.. class:: AST
+
+   This is the base of all AST node classes.  The actual node classes are
+   derived from the :file:`Parser/Python.asdl` file, which is reproduced
+   :ref:`below <abstract-grammar>`.  They are defined in the :mod:`_ast` C
+   module and re-exported in :mod:`ast`.
+
+   There is one class defined for each left-hand side symbol in the abstract
+   grammar (for example, :class:`ast.stmt` or :class:`ast.expr`).  In addition,
+   there is one class defined for each constructor on the right-hand side; these
+   classes inherit from the classes for the left-hand side trees.  For example,
+   :class:`ast.BinOp` inherits from :class:`ast.expr`.  For production rules
+   with alternatives (aka "sums"), the left-hand side class is abstract: only
+   instances of specific constructor nodes are ever created.
+
+   .. attribute:: _fields
+
+      Each concrete class has an attribute :attr:`_fields` which gives the names
+      of all child nodes.
+
+      Each instance of a concrete class has one attribute for each child node,
+      of the type as defined in the grammar.  For example, :class:`ast.BinOp`
+      instances have an attribute :attr:`left` of type :class:`ast.expr`.
+
+      If these attributes are marked as optional in the grammar (using a
+      question mark), the value might be ``None``.  If the attributes can have
+      zero-or-more values (marked with an asterisk), the values are represented
+      as Python lists.  All possible attributes must be present and have valid
+      values when compiling an AST with :func:`compile`.
+
+   .. attribute:: lineno
+                  col_offset
+
+      Instances of :class:`ast.expr` and :class:`ast.stmt` subclasses have
+      :attr:`lineno` and :attr:`col_offset` attributes.  The :attr:`lineno` is
+      the line number of source text (1-indexed so the first line is line 1) and
+      the :attr:`col_offset` is the UTF-8 byte offset of the first token that
+      generated the node.  The UTF-8 offset is recorded because the parser uses
+      UTF-8 internally.
+
+   The constructor of a class :class:`ast.T` parses its arguments as follows:
+
+   * If there are positional arguments, there must be as many as there are items
+     in :attr:`T._fields`; they will be assigned as attributes of these names.
+   * If there are keyword arguments, they will set the attributes of the same
+     names to the given values.
+
+   For example, to create and populate an :class:`ast.UnaryOp` node, you could
+   use ::
+
+      node = ast.UnaryOp()
+      node.op = ast.USub()
+      node.operand = ast.Num()
+      node.operand.n = 5
+      node.operand.lineno = 0
+      node.operand.col_offset = 0
+      node.lineno = 0
+      node.col_offset = 0
+
+   or the more compact ::
+
+      node = ast.UnaryOp(ast.USub(), ast.Num(5, lineno=0, col_offset=0),
+                         lineno=0, col_offset=0)
+
+
+.. _abstract-grammar:
+
+Abstract Grammar
+----------------
+
+The module defines a string constant ``__version__`` which is the decimal
+Subversion revision number of the file shown below.
+
+The abstract grammar is currently defined as follows:
+
+.. literalinclude:: ../../Parser/Python.asdl
+
+
+:mod:`ast` Helpers
+------------------
+
+.. versionadded:: 2.6
+
+Apart from the node classes, :mod:`ast` module defines these utility functions
+and classes for traversing abstract syntax trees:
+
+.. function:: parse(expr, filename='<unknown>', mode='exec')
+
+   Parse an expression into an AST node.  Equivalent to ``compile(expr,
+   filename, mode, PyCF_ONLY_AST)``.
+
+   
+.. function:: literal_eval(node_or_string)
+
+   Safely evaluate an expression node or a string containing a Python
+   expression.  The string or node provided may only consist of the following
+   Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
+   and ``None``.
+
+   This can be used for safely evaluating strings containing Python expressions
+   from untrusted sources without the need to parse the values oneself.
+
+
+.. function:: get_docstring(node, clean=True):
+
+   Return the docstring of the given *node* (which must be a
+   :class:`FunctionDef`, :class:`ClassDef` or :class:`Module` node), or ``None``
+   if it has no docstring.  If *clean* is true, clean up the docstring's
+   indentation with :func:`inspect.cleandoc`.
+
+
+.. function:: fix_missing_locations(node)
+
+   When you compile a node tree with :func:`compile`, the compiler expects
+   :attr:`lineno` and :attr:`col_offset` attributes for every node that supports
+   them.  This is rather tedious to fill in for generated nodes, so this helper
+   adds these attributes recursively where not already set, by setting them to
+   the values of the parent node.  It works recursively starting at *node*.
+
+
+.. function:: increment_lineno(node, n=1)
+
+   Increment the line number of each node in the tree starting at *node* by *n*.
+   This is useful to "move code" to a different location in a file.
+
+
+.. function:: copy_location(new_node, old_node)
+
+   Copy source location (:attr:`lineno` and :attr:`col_offset`) from *old_node*
+   to *new_node* if possible, and return *new_node*.
+
+
+.. function:: iter_fields(node)
+
+   Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields``
+   that is present on *node*.
+
+
+.. function:: iter_child_nodes(node)
+
+   Yield all direct child nodes of *node*, that is, all fields that are nodes
+   and all items of fields that are lists of nodes.
+
+
+.. function:: walk(node)
+
+   Recursively yield all child nodes of *node*, in no specified order.  This is
+   useful if you only want to modify nodes in place and don't care about the
+   context.
+
+
+.. class:: NodeVisitor()
+
+   A node visitor base class that walks the abstract syntax tree and calls a
+   visitor function for every node found.  This function may return a value
+   which is forwarded by the `visit` method.
+
+   This class is meant to be subclassed, with the subclass adding visitor
+   methods.
+
+   .. method:: visit(node)
+
+      Visit a node.  The default implementation calls the method called
+      :samp:`self.visit_{classname}` where *classname* is the name of the node
+      class, or :meth:`generic_visit` if that method doesn't exist.
+
+   .. method:: generic_visit(node)
+
+      This visitor calls :meth:`visit` on all children of the node.
+      
+      Note that child nodes of nodes that have a custom visitor method won't be
+      visited unless the visitor calls :meth:`generic_visit` or visits them
+      itself.
+
+   Don't use the :class:`NodeVisitor` if you want to apply changes to nodes
+   during traversal.  For this a special visitor exists
+   (:class:`NodeTransformer`) that allows modifications.
+
+
+.. class:: NodeTransformer()
+
+   A :class:`NodeVisitor` subclass that walks the abstract syntax tree and
+   allows modification of nodes.
+
+   The `NodeTransformer` will walk the AST and use the return value of the
+   visitor methods to replace or remove the old node.  If the return value of
+   the visitor method is ``None``, the node will be removed from its location,
+   otherwise it is replaced with the return value.  The return value may be the
+   original node in which case no replacement takes place.
+
+   Here is an example transformer that rewrites all occurrences of name lookups
+   (``foo``) to ``data['foo']``::
+
+      class RewriteName(NodeTransformer):
+
+          def visit_Name(self, node):
+              return copy_location(Subscript(
+                  value=Name(id='data', ctx=Load()),
+                  slice=Index(value=Str(s=node.id)),
+                  ctx=node.ctx
+              ), node)
+
+   Keep in mind that if the node you're operating on has child nodes you must
+   either transform the child nodes yourself or call the :meth:`generic_visit`
+   method for the node first.
+
+   For nodes that were part of a collection of statements (that applies to all
+   statement nodes), the visitor may also return a list of nodes rather than
+   just a single node.
+
+   Usually you use the transformer like this::
+
+      node = YourTransformer().visit(node)
+
+
+.. function:: dump(node, annotate_fields=True, include_attributes=False)
+
+   Return a formatted dump of the tree in *node*.  This is mainly useful for
+   debugging purposes.  The returned string will show the names and the values
+   for fields.  This makes the code impossible to evaluate, so if evaluation is
+   wanted *annotate_fields* must be set to False.  Attributes such as line
+   numbers and column offsets are dumped by default.  If this is wanted,
+   *include_attributes* can be set to ``True``.