- basic framework for generic functions, [ticket:615]

- changed the various "literal" generation functions to use an anonymous
bind parameter.  not much changes here except their labels now look
like ":param_1", ":param_2" instead of ":literal"
- from_obj keyword argument to select() can be a scalar or a list.

1 files changed, 24 insertions, 13 deletions

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index c21b102c7..6ad29218f 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -26,10 +26,11 @@ to stay the same in future releases.
 """
 
 import re
+import datetime
 from sqlalchemy import util, exceptions
 from sqlalchemy.sql import operators, visitors
 from sqlalchemy import types as sqltypes
-
+functions = None
 
 __all__ = [
     'Alias', 'ClauseElement', 
@@ -596,7 +597,7 @@ def literal(value, type_=None):
       bind-parameter translation for this literal.
     """
 
-    return _BindParamClause('literal', value, type_=type_, unique=True)
+    return _BindParamClause(None, value, type_=type_, unique=True)
 
 def label(name, obj):
     """Return a [sqlalchemy.sql.expression#_Label] object for the given [sqlalchemy.sql.expression#ColumnElement].
@@ -766,6 +767,14 @@ class _FunctionGenerator(object):
     def __call__(self, *c, **kwargs):
         o = self.opts.copy()
         o.update(kwargs)
+        if len(self.__names) == 1:
+            global functions
+            if functions is None:
+                from sqlalchemy.sql import functions
+            func = getattr(functions, self.__names[-1].lower(), None)
+            if func is not None:
+                return func(*c, **o)
+                
         return _Function(self.__names[-1], packagenames=self.__names[0:-1], *c, **o)
 
 func = _FunctionGenerator()
@@ -798,7 +807,7 @@ def _literal_as_column(element):
     else:
         return element
 
-def _literal_as_binds(element, name='literal', type_=None):
+def _literal_as_binds(element, name=None, type_=None):
     if isinstance(element, Operators):
         return element.expression_element()
     elif _is_literal(element):
@@ -1344,7 +1353,7 @@ class _CompareMixin(ColumnOperators):
         return lambda other: self.__operate(operator, other)
 
     def _bind_param(self, obj):
-        return _BindParamClause('literal', obj, type_=self.type, unique=True)
+        return _BindParamClause(None, obj, type_=self.type, unique=True)
 
     def _check_literal(self, other):
         if isinstance(other, _BindParamClause) and isinstance(other.type, sqltypes.NullType):
@@ -1762,6 +1771,10 @@ class _BindParamClause(ClauseElement, _CompareMixin):
         unicode : sqltypes.NCHAR,
         int : sqltypes.Integer,
         float : sqltypes.Numeric,
+        datetime.date : sqltypes.Date,
+        datetime.datetime : sqltypes.DateTime,
+        datetime.time : sqltypes.Time,
+        datetime.timedelta : sqltypes.Interval,
         type(None):sqltypes.NullType
     }
 
@@ -1997,11 +2010,12 @@ class _Function(_CalculatedClause, FromClause):
     def __init__(self, name, *clauses, **kwargs):
         self.packagenames = kwargs.get('packagenames', None) or []
         self.oid_column = None
-        kwargs['operator'] = operators.comma_op
-        _CalculatedClause.__init__(self, name, **kwargs)
-        for c in clauses:
-            self.append(c)
-
+        self.name = name
+        self._bind = kwargs.get('bind', None)
+        args = [_literal_as_binds(c, self.name) for c in clauses]
+        self.clause_expr = ClauseList(operator=operators.comma_op, group_contents=True, *args).self_group()
+        self.type = sqltypes.to_instance(kwargs.get('type_', None))
+        
     key = property(lambda self:self.name)
     columns = property(lambda self:[self])
 
@@ -2012,9 +2026,6 @@ class _Function(_CalculatedClause, FromClause):
     def get_children(self, **kwargs):
         return _CalculatedClause.get_children(self, **kwargs)
 
-    def append(self, clause):
-        self.clauses.append(_literal_as_binds(clause, self.name))
-
 
 class _Cast(ColumnElement):
 
@@ -2984,7 +2995,7 @@ class Select(_SelectBaseMixin, FromClause):
         if from_obj:
             self._froms = util.Set([
                 _is_literal(f) and _TextFromClause(f) or f
-                for f in from_obj
+                for f in util.to_list(from_obj)
             ])
         else:
             self._froms = util.Set()