diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/misc/cwfs/cwfs.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/misc/cwfs/cwfs.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,175 @@
+# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb 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 Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+"""
+
+"""
+class Schema :
+
+    def __init__(self, schema) :
+        self._schema = schema
+
+    def get_attrs(self, entity) :
+        return self._schema[entity][0]
+
+    def get_relations(self, entity) :
+        return self._schema[entity][1]
+
+    def get_attr_index(self, entity, attr) :
+        return list(self._schema[entity][0]).index(attr)
+
+SCHEMA = Schema({'societe': ( ('nom','ville'),
+                              [('concerne_par','affaire'),
+                               ] ),
+                 'affaire': ( ('ref',),
+                              [('concerne','societe'),
+                               ('concerne_par', 'document')
+                               ] ),
+                 'document':( ('fichier', 'annee','mois','jour','type'),
+                              [('concerne','affaire'),
+                               ] ),
+                 })
+
+
+
+DATA = { 'societe': [ ('CETIAD', 'Dijon'),
+                      ('EDF_R&D', 'Clamart'),
+                      ('Logilab', 'Paris'),
+                      ],
+         'affaire': [ ('CTIA01', 'CETIAD'),
+                      ('EDFR01', 'EDF_R&D'),
+                      ('EDFR02', 'EDF_R&D'),
+                      ],
+         'document':[ ('CTIA01-040906-PRE-1-01.pdf','2004','09','06','PRE','CTIA01'),
+                      ('EDFR01-050201-CLI-1-01.pdf','2005','02','01','CLI','EDFR01'),
+                      ('EDFR01-050322-OFR-1-01.pdf','2005','03','22','OFR','EDFR01'),
+                      ],
+         }
+
+def get_data(entity, where=[]) :
+    for value in DATA[entity] :
+        for index, val in where :
+            if value[index] != val :
+                break
+        else :
+            yield value
+
+class PathParser :
+
+    def __init__(self, schema, path) :
+        self.schema = schema
+        self.path = path
+        self._components = iter([comp for comp in self.path.split('/') if comp])
+        self._entity = None
+        self._attr = None
+        self._rel = None
+        self._restrictions = []
+
+    def parse(self) :
+        self._entity = next(self._components)
+        try:
+            self.process_entity()
+        except StopIteration :
+            pass
+
+    def process_entity(self) :
+        _next = next(self._components)
+        if _next in self.schema.get_attrs(self._entity) :
+            self._attr = _next
+            _next = next(self._components)
+            self._restrictions.append( (self._entity, self._attr, _next) )
+            self._attr = None
+            self._rel = None
+            self.process_entity()
+
+    def get_list(self) :
+        if self._rel :
+            return
+        elif self._attr :
+            where = []
+            for e,a,v in self._restrictions :
+                i = self.schema.get_attr_index(e, a)
+                where.append( (i,v) )
+            i = self.schema.get_attr_index(self._entity, self._attr)
+            for values in get_data(self._entity,where) :
+                yield values[i]+'/'
+        else :
+            attr_restrict = [a for e,a,v in self._restrictions]
+            for attr in self.schema.get_attrs(self._entity) :
+                if attr not in attr_restrict :
+                    yield attr+'/'
+            for data in DATA[self._entity]:
+                yield data[0]
+            for nom, entity in self.schema.get_relations(self._entity) :
+                yield nom+'/'
+                yield entity+'/'
+
+def ls(path) :
+    p = PathParser(SCHEMA,path)
+    p.parse()
+    return list(p.get_list())
+
+
+class SytPathParser :
+
+    def __init__(self, schema, path) :
+        self.schema = schema
+        self.path = path
+        self._components = iter([comp for comp in self.path.split('/') if comp])
+        self._e_type = None
+        self._restrictions = []
+        self._alphabet = list('ABCDEFGHIJKLMNOPQRSTUVWXYZ')
+
+    def parse(self):
+        self._var = self._alphabet.pop(0)
+        self._e_type = next(self._components)
+        e_type = self._e_type.capitalize()
+        self._restrictions.append('%s is %s' % (self._var, e_type))
+        try:
+            self.process_entity()
+        except StopIteration :
+            pass
+        return 'Any %s WHERE %s' % (self._var, ', '.join(self._restrictions))
+
+    def process_entity(self) :
+        _next = next(self._components)
+        if _next in self.schema.get_attrs(self._e_type) :
+            attr = _next
+            try:
+                _next = next(self._components)
+                self._restrictions.append('%s %s %s' % (self._var, attr, _next))
+            except StopIteration:
+                a_var = self._alphabet.pop(0)
+                self._restrictions.append('%s %s %s' % (self._var, attr, a_var) )
+                self._var = a_var
+                raise
+        elif _next in [r for r,e in self.schema.get_relations(self._e_type)]:
+            rel = _next
+            r_var = self._alphabet.pop(0)
+            self._restrictions.append('%s %s %s' % (self._var, rel, r_var))
+            self._var = r_var
+            try:
+                _next = next(self._components)
+                self._restrictions.append('%s is %s' % (r_var, _next.capitalize()))
+            except StopIteration:
+                raise
+        self.process_entity()
+
+
+def to_rql(path) :
+    p = SytPathParser(SCHEMA,path)
+    return p.parse()