diff options
Diffstat (limited to 'lib/sqlalchemy/sql/operators.py')
| -rw-r--r-- | lib/sqlalchemy/sql/operators.py | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/lib/sqlalchemy/sql/operators.py b/lib/sqlalchemy/sql/operators.py index 07fb417fb..f1607c884 100644 --- a/lib/sqlalchemy/sql/operators.py +++ b/lib/sqlalchemy/sql/operators.py @@ -10,7 +10,8 @@ """Defines operators used in SQL expressions.""" from operator import ( - and_, or_, inv, add, mul, sub, mod, truediv, lt, le, ne, gt, ge, eq, neg + and_, or_, inv, add, mul, sub, mod, truediv, lt, le, ne, gt, ge, eq, neg, + getitem ) # Py2K @@ -305,6 +306,15 @@ class ColumnOperators(Operators): """ return self.operate(neg) + def __getitem__(self, index): + """Implement the [] operator. + + This can be used by some database-specific types + such as Postgresql ARRAY and HSTORE. + + """ + return self.operate(getitem, index) + def concat(self, other): """Implement the 'concat' operator. @@ -591,12 +601,18 @@ def is_ordering_modifier(op): _associative = _commutative.union([concat_op, and_, or_]) +_natural_self_precedent = _associative.union([getitem]) +"""Operators where if we have (a op b) op c, we don't want to +parenthesize (a op b). + +""" _smallest = symbol('_smallest', canonical=-100) _largest = symbol('_largest', canonical=100) _PRECEDENCE = { from_: 15, + getitem: 15, mul: 7, truediv: 7, # Py2K @@ -637,7 +653,7 @@ _PRECEDENCE = { def is_precedent(operator, against): - if operator is against and operator in _associative: + if operator is against and operator in _natural_self_precedent: return False else: return (_PRECEDENCE.get(operator, |