add a "mixins.py" module and move some classes around.

- move some Mixins to mixins.py
- move LookupMixIn and *Name to node_classes

It needs more polymorphism, i.e. removing 'isinstance' calls, to move
LookupMixIn and LocalsDictNodeNG to mixins.py .

--HG--
branch : rebuild

1 files changed, 151 insertions, 0 deletions

diff --git a/mixins.py b/mixins.py
new file mode 100644
index 00000000..bed4a447
--- /dev/null
+++ b/mixins.py
@@ -0,0 +1,151 @@
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+"""This module contains some mixins for the different nodes.
+
+:author:    Sylvain Thenault
+:copyright: 2003-2010 LOGILAB S.A. (Paris, FRANCE)
+:contact:   http://www.logilab.fr/ -- mailto:python-projects@logilab.org
+:copyright: 2003-2010 Sylvain Thenault
+:contact:   mailto:thenault@gmail.com
+"""
+
+from logilab.astng import (ASTNGBuildingException, InferenceError,
+                           NotFoundError)
+from logilab.astng.bases import BaseClass
+
+# /!\ We cannot build a StmtNode(NodeNG) class since modifying "__bases__"
+# in "nodes.py" has to work *both* for old-style and new-style classes,
+# but we need the StmtMixIn for scoped nodes
+
+class StmtMixIn(BaseClass):
+    """StmtMixIn used only for a adding a few attributes"""
+    is_statement = True
+
+    def replace(self, child, newchild):
+        sequence = self.child_sequence(child)
+        newchild.parent = self
+        child.parent = None
+        sequence[sequence.index(child)] = newchild
+
+    def next_sibling(self):
+        """return the next sibling statement"""
+        stmts = self.parent.child_sequence(self)
+        index = stmts.index(self)
+        try:
+            return stmts[index +1]
+        except IndexError:
+            pass
+
+    def previous_sibling(self):
+        """return the previous sibling statement"""
+        stmts = self.parent.child_sequence(self)
+        index = stmts.index(self)
+        if index >= 1:
+            return stmts[index -1]
+
+
+class BlockRangeMixIn(BaseClass):
+    """override block range """
+    def set_line_info(self, lastchild):
+        self.fromlineno = self.lineno
+        self.tolineno = lastchild.tolineno
+        self.blockstart_tolineno = self._blockstart_toline()
+
+    def _elsed_block_range(self, lineno, orelse, last=None):
+        """handle block line numbers range for try/finally, for, if and while
+        statements
+        """
+        if lineno == self.fromlineno:
+            return lineno, lineno
+        if orelse:
+            if lineno >= orelse[0].fromlineno:
+                return lineno, orelse[-1].tolineno
+            return lineno, orelse[0].fromlineno - 1
+        return lineno, last or self.tolineno
+
+class FilterStmtsMixin(object):
+    """Mixin for statement filtering and assignment type"""
+
+    def _get_filtered_stmts(self, _, node, _stmts, mystmt):
+        """method used in _filter_stmts to get statemtents and trigger break"""
+        if self.statement() is mystmt:
+            # original node's statement is the assignment, only keep
+            # current node (gen exp, list comp)
+            return [node], True
+        return _stmts, False
+
+    def ass_type(self):
+        return self
+
+
+class AssignTypeMixin(object):
+
+    def ass_type(self):
+        return self
+
+    def _get_filtered_stmts(self, lookup_node, node, _stmts, mystmt):
+        """method used in filter_stmts"""
+        if self is mystmt:
+            return _stmts, True
+        if self.statement() is mystmt:
+            # original node's statement is the assignment, only keep
+            # current node (gen exp, list comp)
+            return [node], True
+        return _stmts, False
+
+
+class ParentAssignTypeMixin(AssignTypeMixin):
+
+    def ass_type(self):
+        return self.parent.ass_type()
+
+
+
+class FromImportMixIn(BaseClass, FilterStmtsMixin):
+    """MixIn for From and Import Nodes"""
+
+    def _infer_name(self, frame, name):
+        return name
+
+    def do_import_module(node, modname):
+        """return the ast for a module whose name is <modname> imported by <node>
+        """
+        # handle special case where we are on a package node importing a module
+        # using the same name as the package, which may end in an infinite loop
+        # on relative imports
+        # XXX: no more needed ?
+        mymodule = node.root()
+        level = getattr(node, 'level', None) # Import as no level
+        if mymodule.absolute_modname(modname, level) == mymodule.name:
+            # FIXME: I don't know what to do here...
+            raise InferenceError('module importing itself: %s' % modname)
+        try:
+            return mymodule.import_module(modname, level=level)
+        except (ASTNGBuildingException, SyntaxError):
+            raise InferenceError(modname)
+
+    def real_name(self, asname):
+        """get name from 'as' name"""
+        for index in range(len(self.names)):
+            name, _asname = self.names[index]
+            if name == '*':
+                return asname
+            if not _asname:
+                name = name.split('.', 1)[0]
+                _asname = name
+            if asname == _asname:
+                return name
+        raise NotFoundError(asname)
+
+
+