add hg and python

9 files changed, 924 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Demo/parser/FILES b/sys/src/cmd/python/Demo/parser/FILES
new file mode 100644
index 000000000..1ff59a31a
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/FILES
@@ -0,0 +1,6 @@
+Demo/parser
+Doc/libparser.tex
+Lib/AST.py
+Lib/symbol.py
+Lib/token.py
+Modules/parsermodule.c
diff --git a/sys/src/cmd/python/Demo/parser/README b/sys/src/cmd/python/Demo/parser/README
new file mode 100644
index 000000000..a576d33b0
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/README
@@ -0,0 +1,31 @@
+These files are from the large example of using the `parser' module.  Refer
+to the Python Library Reference for more information.
+
+It also contains examples for the AST parser.
+
+Files:
+------
+
+	FILES	     -- list of files associated with the parser module.
+
+	README	     -- this file.
+
+	example.py   --	module that uses the `parser' module to extract
+			information from the parse tree of Python source
+			code.
+
+	docstring.py -- sample source file containing only a module docstring.
+
+	simple.py    -- sample source containing a "short form" definition.
+
+	source.py    --	sample source code used to demonstrate ability to
+			handle nested constructs easily using the functions
+			and classes in example.py.
+
+	test_parser.py  program to put the parser module through its paces.
+
+	unparse.py	AST (2.5) based example to recreate source code
+			from an AST. This is incomplete; contributions
+			are welcome.
+
+Enjoy!
diff --git a/sys/src/cmd/python/Demo/parser/docstring.py b/sys/src/cmd/python/Demo/parser/docstring.py
new file mode 100644
index 000000000..45a261b61
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/docstring.py
@@ -0,0 +1,2 @@
+"""Some documentation.
+"""
diff --git a/sys/src/cmd/python/Demo/parser/example.py b/sys/src/cmd/python/Demo/parser/example.py
new file mode 100644
index 000000000..2aa9ec285
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/example.py
@@ -0,0 +1,190 @@
+"""Simple code to extract class & function docstrings from a module.
+
+This code is used as an example in the library reference manual in the
+section on using the parser module.  Refer to the manual for a thorough
+discussion of the operation of this code.
+"""
+
+import os
+import parser
+import symbol
+import token
+import types
+
+from types import ListType, TupleType
+
+
+def get_docs(fileName):
+    """Retrieve information from the parse tree of a source file.
+
+    fileName
+        Name of the file to read Python source code from.
+    """
+    source = open(fileName).read()
+    basename = os.path.basename(os.path.splitext(fileName)[0])
+    ast = parser.suite(source)
+    return ModuleInfo(ast.totuple(), basename)
+
+
+class SuiteInfoBase:
+    _docstring = ''
+    _name = ''
+
+    def __init__(self, tree = None):
+        self._class_info = {}
+        self._function_info = {}
+        if tree:
+            self._extract_info(tree)
+
+    def _extract_info(self, tree):
+        # extract docstring
+        if len(tree) == 2:
+            found, vars = match(DOCSTRING_STMT_PATTERN[1], tree[1])
+        else:
+            found, vars = match(DOCSTRING_STMT_PATTERN, tree[3])
+        if found:
+            self._docstring = eval(vars['docstring'])
+        # discover inner definitions
+        for node in tree[1:]:
+            found, vars = match(COMPOUND_STMT_PATTERN, node)
+            if found:
+                cstmt = vars['compound']
+                if cstmt[0] == symbol.funcdef:
+                    name = cstmt[2][1]
+                    self._function_info[name] = FunctionInfo(cstmt)
+                elif cstmt[0] == symbol.classdef:
+                    name = cstmt[2][1]
+                    self._class_info[name] = ClassInfo(cstmt)
+
+    def get_docstring(self):
+        return self._docstring
+
+    def get_name(self):
+        return self._name
+
+    def get_class_names(self):
+        return self._class_info.keys()
+
+    def get_class_info(self, name):
+        return self._class_info[name]
+
+    def __getitem__(self, name):
+        try:
+            return self._class_info[name]
+        except KeyError:
+            return self._function_info[name]
+
+
+class SuiteFuncInfo:
+    #  Mixin class providing access to function names and info.
+
+    def get_function_names(self):
+        return self._function_info.keys()
+
+    def get_function_info(self, name):
+        return self._function_info[name]
+
+
+class FunctionInfo(SuiteInfoBase, SuiteFuncInfo):
+    def __init__(self, tree = None):
+        self._name = tree[2][1]
+        SuiteInfoBase.__init__(self, tree and tree[-1] or None)
+
+
+class ClassInfo(SuiteInfoBase):
+    def __init__(self, tree = None):
+        self._name = tree[2][1]
+        SuiteInfoBase.__init__(self, tree and tree[-1] or None)
+
+    def get_method_names(self):
+        return self._function_info.keys()
+
+    def get_method_info(self, name):
+        return self._function_info[name]
+
+
+class ModuleInfo(SuiteInfoBase, SuiteFuncInfo):
+    def __init__(self, tree = None, name = "<string>"):
+        self._name = name
+        SuiteInfoBase.__init__(self, tree)
+        if tree:
+            found, vars = match(DOCSTRING_STMT_PATTERN, tree[1])
+            if found:
+                self._docstring = vars["docstring"]
+
+
+def match(pattern, data, vars=None):
+    """Match `data' to `pattern', with variable extraction.
+
+    pattern
+        Pattern to match against, possibly containing variables.
+
+    data
+        Data to be checked and against which variables are extracted.
+
+    vars
+        Dictionary of variables which have already been found.  If not
+        provided, an empty dictionary is created.
+
+    The `pattern' value may contain variables of the form ['varname'] which
+    are allowed to match anything.  The value that is matched is returned as
+    part of a dictionary which maps 'varname' to the matched value.  'varname'
+    is not required to be a string object, but using strings makes patterns
+    and the code which uses them more readable.
+
+    This function returns two values: a boolean indicating whether a match
+    was found and a dictionary mapping variable names to their associated
+    values.
+    """
+    if vars is None:
+        vars = {}
+    if type(pattern) is ListType:       # 'variables' are ['varname']
+        vars[pattern[0]] = data
+        return 1, vars
+    if type(pattern) is not TupleType:
+        return (pattern == data), vars
+    if len(data) != len(pattern):
+        return 0, vars
+    for pattern, data in map(None, pattern, data):
+        same, vars = match(pattern, data, vars)
+        if not same:
+            break
+    return same, vars
+
+
+#  This pattern identifies compound statements, allowing them to be readily
+#  differentiated from simple statements.
+#
+COMPOUND_STMT_PATTERN = (
+    symbol.stmt,
+    (symbol.compound_stmt, ['compound'])
+    )
+
+
+#  This pattern will match a 'stmt' node which *might* represent a docstring;
+#  docstrings require that the statement which provides the docstring be the
+#  first statement in the class or function, which this pattern does not check.
+#
+DOCSTRING_STMT_PATTERN = (
+    symbol.stmt,
+    (symbol.simple_stmt,
+     (symbol.small_stmt,
+      (symbol.expr_stmt,
+       (symbol.testlist,
+        (symbol.test,
+         (symbol.and_test,
+          (symbol.not_test,
+           (symbol.comparison,
+            (symbol.expr,
+             (symbol.xor_expr,
+              (symbol.and_expr,
+               (symbol.shift_expr,
+                (symbol.arith_expr,
+                 (symbol.term,
+                  (symbol.factor,
+                   (symbol.power,
+                    (symbol.atom,
+                     (token.STRING, ['docstring'])
+                     )))))))))))))))),
+     (token.NEWLINE, '')
+     ))
diff --git a/sys/src/cmd/python/Demo/parser/simple.py b/sys/src/cmd/python/Demo/parser/simple.py
new file mode 100644
index 000000000..184e2fe5d
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/simple.py
@@ -0,0 +1 @@
+def f(): "maybe a docstring"
diff --git a/sys/src/cmd/python/Demo/parser/source.py b/sys/src/cmd/python/Demo/parser/source.py
new file mode 100644
index 000000000..b90062851
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/source.py
@@ -0,0 +1,27 @@
+"""Exmaple file to be parsed for the parsermodule example.
+
+The classes and functions in this module exist only to exhibit the ability
+of the handling information extraction from nested definitions using parse
+trees.  They shouldn't interest you otherwise!
+"""
+
+class Simple:
+    "This class does very little."
+
+    def method(self):
+        "This method does almost nothing."
+        return 1
+
+    class Nested:
+        "This is a nested class."
+
+        def nested_method(self):
+            "Method of Nested class."
+            def nested_function():
+                "Function in method of Nested class."
+                pass
+            return nested_function
+
+def function():
+    "This function lives at the module level."
+    return 0
diff --git a/sys/src/cmd/python/Demo/parser/test_parser.py b/sys/src/cmd/python/Demo/parser/test_parser.py
new file mode 100755
index 000000000..be39bca7f
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/test_parser.py
@@ -0,0 +1,48 @@
+#! /usr/bin/env python
+#  (Force the script to use the latest build.)
+#
+#  test_parser.py
+
+import parser, traceback
+
+_numFailed = 0
+
+def testChunk(t, fileName):
+    global _numFailed
+    print '----', fileName,
+    try:
+        ast = parser.suite(t)
+        tup = parser.ast2tuple(ast)
+        # this discards the first AST; a huge memory savings when running
+        # against a large source file like Tkinter.py.
+        ast = None
+        new = parser.tuple2ast(tup)
+    except parser.ParserError, err:
+        print
+        print 'parser module raised exception on input file', fileName + ':'
+        traceback.print_exc()
+        _numFailed = _numFailed + 1
+    else:
+        if tup != parser.ast2tuple(new):
+            print
+            print 'parser module failed on input file', fileName
+            _numFailed = _numFailed + 1
+        else:
+            print 'o.k.'
+
+def testFile(fileName):
+    t = open(fileName).read()
+    testChunk(t, fileName)
+
+def test():
+    import sys
+    args = sys.argv[1:]
+    if not args:
+        import glob
+        args = glob.glob("*.py")
+        args.sort()
+    map(testFile, args)
+    sys.exit(_numFailed != 0)
+
+if __name__ == '__main__':
+    test()
diff --git a/sys/src/cmd/python/Demo/parser/texipre.dat b/sys/src/cmd/python/Demo/parser/texipre.dat
new file mode 100644
index 000000000..8ad03a617
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/texipre.dat
@@ -0,0 +1,100 @@
+\input texinfo   @c -*-texinfo-*-
+@c %**start of header
+@setfilename parser.info
+@settitle Python Parser Module Reference
+@setchapternewpage odd
+@footnotestyle end
+@c %**end of header
+
+@ifinfo
+This file describes the interfaces
+published by the optional @code{parser} module and gives examples of
+how they may be used.  It contains the same text as the chapter on the
+@code{parser} module in the @cite{Python Library Reference}, but is
+presented as a separate document.
+
+Copyright 1995-1996 by Fred L. Drake, Jr., Reston, Virginia, USA, and
+Virginia Polytechnic Institute and State University, Blacksburg,
+Virginia, USA.  Portions of the software copyright 1991-1995 by
+Stichting Mathematisch Centrum, Amsterdam, The Netherlands.  Copying is
+permitted under the terms associated with the main Python distribution,
+with the additional restriction that this additional notice be included
+and maintained on all distributed copies.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Fred L. Drake, Jr. and
+Virginia Polytechnic Institute and State University not be used in
+advertising or publicity pertaining to distribution of the software
+without specific, written prior permission.
+
+FRED L. DRAKE, JR. AND VIRGINIA POLYTECHNIC INSTITUTE AND STATE
+UNIVERSITY DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+EVENT SHALL FRED L. DRAKE, JR. OR VIRGINIA POLYTECHNIC INSTITUTE AND
+STATE UNIVERSITY BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+@end ifinfo
+
+@titlepage
+@title Python Parser Module Reference
+@author Fred L. Drake, Jr.
+
+@c  The following two commands start the copyright page.
+@page
+@vskip 0pt plus 1filll
+Copyright 1995-1996 by Fred L. Drake, Jr., Reston, Virginia, USA, and
+Virginia Polytechnic Institute and State University, Blacksburg,
+Virginia, USA.  Portions of the software copyright 1991-1995 by
+Stichting Mathematisch Centrum, Amsterdam, The Netherlands.  Copying is
+permitted under the terms associated with the main Python distribution,
+with the additional restriction that this additional notice be included
+and maintained on all distributed copies.
+
+@center All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Fred L. Drake, Jr. and
+Virginia Polytechnic Institute and State University not be used in
+advertising or publicity pertaining to distribution of the software
+without specific, written prior permission.
+
+FRED L. DRAKE, JR. AND VIRGINIA POLYTECHNIC INSTITUTE AND STATE
+UNIVERSITY DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+EVENT SHALL FRED L. DRAKE, JR. OR VIRGINIA POLYTECHNIC INSTITUTE AND
+STATE UNIVERSITY BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+@end titlepage
+
+
+@node Top, Overview, (dir), (dir)
+@top The Python Parser Module
+
+@ifinfo
+This file describes the interfaces
+published by the optional @code{parser} module and gives examples of
+how they may be used.  It contains the same text as the chapter on the
+@code{parser} module in the @cite{Python Library Reference}, but is
+presented as a separate document.
+
+This version corresponds to Python version 1.4 (1 Sept. 1996).
+
+@end ifinfo
+
+@c placeholder for the master menu -- patched by texinfo-all-menus-update
+@menu
+@end menu
diff --git a/sys/src/cmd/python/Demo/parser/unparse.py b/sys/src/cmd/python/Demo/parser/unparse.py
new file mode 100644
index 000000000..f4dd90c95
--- /dev/null
+++ b/sys/src/cmd/python/Demo/parser/unparse.py
@@ -0,0 +1,519 @@
+"Usage: unparse.py <path to source file>"
+import sys
+import _ast
+import cStringIO
+import os
+
+class Unparser:
+    """Methods in this class recursively traverse an AST and
+    output source code for the abstract syntax; original formatting
+    is disregarged. """
+
+    def __init__(self, tree, file = sys.stdout):
+        """Unparser(tree, file=sys.stdout) -> None.
+         Print the source for tree to file."""
+        self.f = file
+        self._indent = 0
+        self.dispatch(tree)
+        print >>self.f,""
+        self.f.flush()
+
+    def fill(self, text = ""):
+        "Indent a piece of text, according to the current indentation level"
+        self.f.write("\n"+"    "*self._indent + text)
+
+    def write(self, text):
+        "Append a piece of text to the current line."
+        self.f.write(text)
+
+    def enter(self):
+        "Print ':', and increase the indentation."
+        self.write(":")
+        self._indent += 1
+
+    def leave(self):
+        "Decrease the indentation level."
+        self._indent -= 1
+
+    def dispatch(self, tree):
+        "Dispatcher function, dispatching tree type T to method _T."
+        if isinstance(tree, list):
+            for t in tree:
+                self.dispatch(t)
+            return
+        meth = getattr(self, "_"+tree.__class__.__name__)
+        meth(tree)
+
+
+    ############### Unparsing methods ######################
+    # There should be one method per concrete grammar type #
+    # Constructors should be grouped by sum type. Ideally, #
+    # this would follow the order in the grammar, but      #
+    # currently doesn't.                                   #
+    ########################################################
+
+    def _Module(self, tree):
+        for stmt in tree.body:
+            self.dispatch(stmt)
+
+    # stmt
+    def _Expr(self, tree):
+        self.fill()
+        self.dispatch(tree.value)
+
+    def _Import(self, t):
+        self.fill("import ")
+        first = True
+        for a in t.names:
+            if first:
+                first = False
+            else:
+                self.write(", ")
+            self.write(a.name)
+            if a.asname:
+                self.write(" as "+a.asname)
+
+    def _ImportFrom(self, t):
+        self.fill("from ")
+        self.write(t.module)
+        self.write(" import ")
+        for i, a in enumerate(t.names):
+            if i == 0:
+                self.write(", ")
+            self.write(a.name)
+            if a.asname:
+                self.write(" as "+a.asname)
+        # XXX(jpe) what is level for?
+
+    def _Assign(self, t):
+        self.fill()
+        for target in t.targets:
+            self.dispatch(target)
+            self.write(" = ")
+        self.dispatch(t.value)
+
+    def _AugAssign(self, t):
+        self.fill()
+        self.dispatch(t.target)
+        self.write(" "+self.binop[t.op.__class__.__name__]+"= ")
+        self.dispatch(t.value)
+
+    def _Return(self, t):
+        self.fill("return ")
+        if t.value:
+            self.dispatch(t.value)
+
+    def _Pass(self, t):
+        self.fill("pass")
+
+    def _Break(self, t):
+        self.fill("break")
+
+    def _Continue(self, t):
+        self.fill("continue")
+
+    def _Delete(self, t):
+        self.fill("del ")
+        self.dispatch(t.targets)
+
+    def _Assert(self, t):
+        self.fill("assert ")
+        self.dispatch(t.test)
+        if t.msg:
+            self.write(", ")
+            self.dispatch(t.msg)
+
+    def _Exec(self, t):
+        self.fill("exec ")
+        self.dispatch(t.body)
+        if t.globals:
+            self.write(" in ")
+            self.dispatch(t.globals)
+        if t.locals:
+            self.write(", ")
+            self.dispatch(t.locals)
+
+    def _Print(self, t):
+        self.fill("print ")
+        do_comma = False
+        if t.dest:
+            self.write(">>")
+            self.dispatch(t.dest)
+            do_comma = True
+        for e in t.values:
+            if do_comma:self.write(", ")
+            else:do_comma=True
+            self.dispatch(e)
+        if not t.nl:
+            self.write(",")
+
+    def _Global(self, t):
+        self.fill("global")
+        for i, n in enumerate(t.names):
+            if i != 0:
+                self.write(",")
+            self.write(" " + n)
+
+    def _Yield(self, t):
+        self.fill("yield")
+        if t.value:
+            self.write(" (")
+            self.dispatch(t.value)
+            self.write(")")
+
+    def _Raise(self, t):
+        self.fill('raise ')
+        if t.type:
+            self.dispatch(t.type)
+        if t.inst:
+            self.write(", ")
+            self.dispatch(t.inst)
+        if t.tback:
+            self.write(", ")
+            self.dispatch(t.tback)
+
+    def _TryExcept(self, t):
+        self.fill("try")
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+        for ex in t.handlers:
+            self.dispatch(ex)
+        if t.orelse:
+            self.fill("else")
+            self.enter()
+            self.dispatch(t.orelse)
+            self.leave()
+
+    def _TryFinally(self, t):
+        self.fill("try")
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+        self.fill("finally")
+        self.enter()
+        self.dispatch(t.finalbody)
+        self.leave()
+
+    def _excepthandler(self, t):
+        self.fill("except ")
+        if t.type:
+            self.dispatch(t.type)
+        if t.name:
+            self.write(", ")
+            self.dispatch(t.name)
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+    def _ClassDef(self, t):
+        self.write("\n")
+        self.fill("class "+t.name)
+        if t.bases:
+            self.write("(")
+            for a in t.bases:
+                self.dispatch(a)
+                self.write(", ")
+            self.write(")")
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+    def _FunctionDef(self, t):
+        self.write("\n")
+        for deco in t.decorators:
+            self.fill("@")
+            self.dispatch(deco)
+        self.fill("def "+t.name + "(")
+        self.dispatch(t.args)
+        self.write(")")
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+    def _For(self, t):
+        self.fill("for ")
+        self.dispatch(t.target)
+        self.write(" in ")
+        self.dispatch(t.iter)
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+        if t.orelse:
+            self.fill("else")
+            self.enter()
+            self.dispatch(t.orelse)
+            self.leave
+
+    def _If(self, t):
+        self.fill("if ")
+        self.dispatch(t.test)
+        self.enter()
+        # XXX elif?
+        self.dispatch(t.body)
+        self.leave()
+        if t.orelse:
+            self.fill("else")
+            self.enter()
+            self.dispatch(t.orelse)
+            self.leave()
+
+    def _While(self, t):
+        self.fill("while ")
+        self.dispatch(t.test)
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+        if t.orelse:
+            self.fill("else")
+            self.enter()
+            self.dispatch(t.orelse)
+            self.leave
+
+    def _With(self, t):
+        self.fill("with ")
+        self.dispatch(t.context_expr)
+        if t.optional_vars:
+            self.write(" as ")
+            self.dispatch(t.optional_vars)
+        self.enter()
+        self.dispatch(t.body)
+        self.leave()
+
+    # expr
+    def _Str(self, tree):
+        self.write(repr(tree.s))
+
+    def _Name(self, t):
+        self.write(t.id)
+
+    def _Repr(self, t):
+        self.write("`")
+        self.dispatch(t.value)
+        self.write("`")
+
+    def _Num(self, t):
+        self.write(repr(t.n))
+
+    def _List(self, t):
+        self.write("[")
+        for e in t.elts:
+            self.dispatch(e)
+            self.write(", ")
+        self.write("]")
+
+    def _ListComp(self, t):
+        self.write("[")
+        self.dispatch(t.elt)
+        for gen in t.generators:
+            self.dispatch(gen)
+        self.write("]")
+
+    def _GeneratorExp(self, t):
+        self.write("(")
+        self.dispatch(t.elt)
+        for gen in t.generators:
+            self.dispatch(gen)
+        self.write(")")
+
+    def _comprehension(self, t):
+        self.write(" for ")
+        self.dispatch(t.target)
+        self.write(" in ")
+        self.dispatch(t.iter)
+        for if_clause in t.ifs:
+            self.write(" if ")
+            self.dispatch(if_clause)
+
+    def _IfExp(self, t):
+        self.dispatch(t.body)
+        self.write(" if ")
+        self.dispatch(t.test)
+        if t.orelse:
+            self.write(" else ")
+            self.dispatch(t.orelse)
+
+    def _Dict(self, t):
+        self.write("{")
+        for k,v in zip(t.keys, t.values):
+            self.dispatch(k)
+            self.write(" : ")
+            self.dispatch(v)
+            self.write(", ")
+        self.write("}")
+
+    def _Tuple(self, t):
+        if not t.elts:
+            self.write("()")
+            return
+        self.write("(")
+        for e in t.elts:
+            self.dispatch(e)
+            self.write(", ")
+        self.write(")")
+
+    unop = {"Invert":"~", "Not": "not", "UAdd":"+", "USub":"-"}
+    def _UnaryOp(self, t):
+        self.write(self.unop[t.op.__class__.__name__])
+        self.write("(")
+        self.dispatch(t.operand)
+        self.write(")")
+
+    binop = { "Add":"+", "Sub":"-", "Mult":"*", "Div":"/", "Mod":"%",
+                    "LShift":">>", "RShift":"<<", "BitOr":"|", "BitXor":"^", "BitAnd":"&",
+                    "FloorDiv":"//", "Pow": "**"}
+    def _BinOp(self, t):
+        self.write("(")
+        self.dispatch(t.left)
+        self.write(")" + self.binop[t.op.__class__.__name__] + "(")
+        self.dispatch(t.right)
+        self.write(")")
+
+    cmpops = {"Eq":"==", "NotEq":"!=", "Lt":"<", "LtE":"<=", "Gt":">", "GtE":">=",
+                        "Is":"is", "IsNot":"is not", "In":"in", "NotIn":"not in"}
+    def _Compare(self, t):
+        self.write("(")
+        self.dispatch(t.left)
+        for o, e in zip(t.ops, t.comparators):
+            self.write(") " +self.cmpops[o.__class__.__name__] + " (")
+            self.dispatch(e)
+            self.write(")")
+
+    boolops = {_ast.And: 'and', _ast.Or: 'or'}
+    def _BoolOp(self, t):
+        self.write("(")
+        self.dispatch(t.values[0])
+        for v in t.values[1:]:
+            self.write(" %s " % self.boolops[t.op.__class__])
+            self.dispatch(v)
+        self.write(")")
+
+    def _Attribute(self,t):
+        self.dispatch(t.value)
+        self.write(".")
+        self.write(t.attr)
+
+    def _Call(self, t):
+        self.dispatch(t.func)
+        self.write("(")
+        comma = False
+        for e in t.args:
+            if comma: self.write(", ")
+            else: comma = True
+            self.dispatch(e)
+        for e in t.keywords:
+            if comma: self.write(", ")
+            else: comma = True
+            self.dispatch(e)
+        if t.starargs:
+            if comma: self.write(", ")
+            else: comma = True
+            self.write("*")
+            self.dispatch(t.starargs)
+        if t.kwargs:
+            if comma: self.write(", ")
+            else: comma = True
+            self.write("**")
+            self.dispatch(t.kwargs)
+        self.write(")")
+
+    def _Subscript(self, t):
+        self.dispatch(t.value)
+        self.write("[")
+        self.dispatch(t.slice)
+        self.write("]")
+
+    # slice
+    def _Ellipsis(self, t):
+        self.write("...")
+
+    def _Index(self, t):
+        self.dispatch(t.value)
+
+    def _Slice(self, t):
+        if t.lower:
+            self.dispatch(t.lower)
+        self.write(":")
+        if t.upper:
+            self.dispatch(t.upper)
+        if t.step:
+            self.write(":")
+            self.dispatch(t.step)
+
+    def _ExtSlice(self, t):
+        for i, d in enumerate(t.dims):
+            if i != 0:
+                self.write(': ')
+            self.dispatch(d)
+
+    # others
+    def _arguments(self, t):
+        first = True
+        nonDef = len(t.args)-len(t.defaults)
+        for a in t.args[0:nonDef]:
+            if first:first = False
+            else: self.write(", ")
+            self.dispatch(a)
+        for a,d in zip(t.args[nonDef:], t.defaults):
+            if first:first = False
+            else: self.write(", ")
+            self.dispatch(a),
+            self.write("=")
+            self.dispatch(d)
+        if t.vararg:
+            if first:first = False
+            else: self.write(", ")
+            self.write("*"+t.vararg)
+        if t.kwarg:
+            if first:first = False
+            else: self.write(", ")
+            self.write("**"+t.kwarg)
+
+    def _keyword(self, t):
+        self.write(t.arg)
+        self.write("=")
+        self.dispatch(t.value)
+
+    def _Lambda(self, t):
+        self.write("lambda ")
+        self.dispatch(t.args)
+        self.write(": ")
+        self.dispatch(t.body)
+
+def roundtrip(filename, output=sys.stdout):
+    source = open(filename).read()
+    tree = compile(source, filename, "exec", 0x400)
+    Unparser(tree, output)
+
+
+
+def testdir(a):
+    try:
+        names = [n for n in os.listdir(a) if n.endswith('.py')]
+    except OSError:
+        print >> sys.stderr, "Directory not readable: %s" % a
+    else:
+        for n in names:
+            fullname = os.path.join(a, n)
+            if os.path.isfile(fullname):
+                output = cStringIO.StringIO()
+                print 'Testing %s' % fullname
+                try:
+                    roundtrip(fullname, output)
+                except Exception, e:
+                    print '  Failed to compile, exception is %s' % repr(e)
+            elif os.path.isdir(fullname):
+                testdir(fullname)
+
+def main(args):
+    if args[0] == '--testdir':
+        for a in args[1:]:
+            testdir(a)
+    else:
+        for a in args:
+            roundtrip(a)
+
+if __name__=='__main__':
+    main(sys.argv[1:])