[Python-checkins] r53382 - in sandbox/trunk/2to3: example.py fixes/basefix.py fixes/fix_except.py pgen2/parse.py refactor.py

Thu Jan 11 20:02:09 CET 2007

Author: guido.van.rossum
Date: Thu Jan 11 20:02:08 2007
New Revision: 53382
Modified:
 sandbox/trunk/2to3/example.py
 sandbox/trunk/2to3/fixes/basefix.py
 sandbox/trunk/2to3/fixes/fix_except.py
 sandbox/trunk/2to3/pgen2/parse.py
 sandbox/trunk/2to3/refactor.py
Log:
Collin Winter's improvements to fix_except.py.
I changed new_name() slightly, and got rid of a spurious 'o' in a docstring.
Modified: sandbox/trunk/2to3/example.py
==============================================================================

--- sandbox/trunk/2to3/example.py	(original)
+++ sandbox/trunk/2to3/example.py	Thu Jan 11 20:02:08 2007
@@ -162,7 +162,9 @@
 def except_examples():
 try:
 pass
- except Exception, e:
+ except Exception, (f, e):
+ pass
+ except ImportError, e:
 pass
 #
 try:
@@ -170,8 +172,6 @@
 except (RuntimeError, ImportError), e:
 pass
 #
- # These should not be touched
- #
 try:
 pass
 except Exception, (a, b):
@@ -192,6 +192,13 @@
 except Exception, a().foo:
 pass
 #
+ # These should not be touched:
+ #
+ try:
+ pass
+ except:
+ pass
+ #
 try:
 pass
 except Exception:
@@ -199,7 +206,8 @@
 #
 try:
 pass
- except (RuntimeError, ImportError):
+ except (Exception, SystemExit):
 pass
 
+ 
 # This is the last line.
Modified: sandbox/trunk/2to3/fixes/basefix.py
==============================================================================
--- sandbox/trunk/2to3/fixes/basefix.py	(original)
+++ sandbox/trunk/2to3/fixes/basefix.py	Thu Jan 11 20:02:08 2007
@@ -5,11 +5,14 @@
 
 # Python imports
 import logging
+import itertools
 
 # Local imports
 import patcomp
 import pygram
 
+# For new_name()
+numbers = itertools.count(1)
 
 class BaseFix(object):
 
@@ -26,13 +29,14 @@
 options = None # Options object passed to initializer
 filename = None # The filename (set by set_filename)
 logger = None # A logger (set by set_filename)
+ used_names = set() # A set of all used NAMEs
 
 # Shortcut for access to Python grammar symbols
 syms = pygram.python_symbols
 
 def __init__(self, options):
 """Initializer. Subclass may override.
-o
+
 The argument is an optparse.Values instance which can be used
 to inspect the command line options.
 """
@@ -80,3 +84,10 @@
 def parenthesize(self, node):
 """Wrapper around pygram.parenthesize()."""
 return pygram.parenthesize(node)
+
+ def new_name(self, template="xxx_todo_changeme"):
+ name = template
+ while name in self.used_names:
+ name = template + str(numbers.next())
+ self.used_names.add(name)
+ return name
Modified: sandbox/trunk/2to3/fixes/fix_except.py
==============================================================================
--- sandbox/trunk/2to3/fixes/fix_except.py	(original)
+++ sandbox/trunk/2to3/fixes/fix_except.py	Thu Jan 11 20:02:08 2007
@@ -2,6 +2,7 @@
 
 # Python imports
 import token
+import pprint
 
 # Local imports
 import pytree
@@ -13,11 +14,27 @@
 return
 node = node.children[0]
 return node.lineno
+ 
+def find_excepts(nodes):
+ for i in range(len(nodes)):
+ n = nodes[i]
+ if isinstance(n, pytree.Node):
+ if n.children[0].value == 'except':
+ yield (n, nodes[i+2])
+
+as_leaf = pytree.Leaf(token.NAME, "as")
+as_leaf.set_prefix(" ")
+
+ass_leaf = pytree.Leaf(token.EQUAL, "=")
+ass_leaf.set_prefix(" ")
 
 class FixExcept(basefix.BaseFix):
 
 PATTERN = """
- except_clause< 'except' a=any ',' b=any >
+ try_stmt< 'try' ':' suite
+ cleanup=((except_clause ':' suite)+ ['else' ':' suite]
+ ['finally' ':' suite]
+	 | 'finally' ':' suite) >
 """
 
 def transform(self, node):
@@ -25,27 +42,38 @@
 results = self.match(node)
 assert results
 
- a = results["a"].clone()
- b = results["b"].clone()
- 
- if b.type != token.NAME:
- lineno = get_lineno(node)
- self.logger.warning("At line %s, unable to transform: %s" %
- (lineno, node))
- return node
- 
- as_leaf = pytree.Leaf(token.NAME, "as")
- as_leaf.set_prefix(" ")
- 
- # Python 2 excepts could take the form except E,V: (no space)
- # That doesn't work for the new version
- if not b.get_prefix():
- b.set_prefix(" ")
+ try_cleanup = [ch.clone() for ch in results['cleanup']]
+ for except_clause, e_suite in find_excepts(try_cleanup):
+ if len(except_clause.children) == 4:
+ (E, comma, N) = except_clause.children[1:4]
+ comma.replace(as_leaf.clone())
+ if str(N).strip()[0] == '(':
+ # We're dealing with a tuple
+ lineno = get_lineno(N)
+ msg = "At line %d, exception unpacking is going away"
+ self.logger.warning(msg % lineno)
+ elif N.type != token.NAME:
+ # Generate a new N for the except clause
+ new_N = pytree.Leaf(token.NAME, self.new_name())
+ new_N.set_prefix(" ")
+ target = N.clone()
+ target.set_prefix("")
+ N.replace(new_N)
+ 
+ # Insert "old_N = new_N" as the first statement in
+ # the except body
+ suite_stmts = list(e_suite.children)
+ for i, stmt in enumerate(suite_stmts):
+ if isinstance(stmt, pytree.Node):
+ break
+ assign = pytree.Node(syms.atom,
+ [target,
+ ass_leaf.clone(),
+ new_N.clone()])
+ 
+ assign.parent = e_suite 
+ suite_stmts = suite_stmts[:i] + [assign] + suite_stmts
+ e_suite.children = tuple(suite_stmts)
 
- new = pytree.Node(syms.except_clause,
- [pytree.Leaf(token.NAME, "except"),
- pytree.Node(syms.test, [a]),
- as_leaf,
- pytree.Node(syms.test, [b])])
- new.set_prefix(node.get_prefix())
- return new
+ children = [c.clone() for c in node.children[:3]] + try_cleanup
+ return pytree.Node(node.type, children)
Modified: sandbox/trunk/2to3/pgen2/parse.py
==============================================================================
--- sandbox/trunk/2to3/pgen2/parse.py	(original)
+++ sandbox/trunk/2to3/pgen2/parse.py	Thu Jan 11 20:02:08 2007
@@ -108,6 +108,7 @@
 stackentry = (self.grammar.dfas[start], 0, newnode)
 self.stack = [stackentry]
 self.rootnode = None
+ self.used_names = set() # Aliased to self.rootnode.used_names in pop()
 
 def addtoken(self, type, value, context):
 """Add a token; return True iff this is the end of the program."""
@@ -160,6 +161,8 @@
 def classify(self, type, value, context):
 """Turn a token into a label. (Internal)"""
 if type == token.NAME:
+ # Keep a listing of all used names
+ self.used_names.add(value)
 # Check for reserved words
 ilabel = self.grammar.keywords.get(value)
 if ilabel is not None:
@@ -195,3 +198,4 @@
 node[-1].append(newnode)
 else:
 self.rootnode = newnode
+ self.rootnode.used_names = self.used_names
Modified: sandbox/trunk/2to3/refactor.py
==============================================================================
--- sandbox/trunk/2to3/refactor.py	(original)
+++ sandbox/trunk/2to3/refactor.py	Thu Jan 11 20:02:08 2007
@@ -195,6 +195,7 @@
 """Refactors a parse tree."""
 for fixer in self.fixers:
 fixer.set_filename(filename)
+ fixer.used_names = tree.used_names
 changes = 0
 for node in tree.post_order():
 for fixer in self.fixers:
