def create(cls, label, kind, context = None, **attributes):
r'''Creates a new symbol_table entry.
Updates an existing database row (if found), or inserts a new row.
Returns the id of the row.
'''
if context is None:
id = crud.read1_column('symbol_table', 'id',
label=label, context=None,
zero_ok=True)
if id is not None:
crud.update('symbol_table', {'id': id}, kind=kind,
**attributes)
if id in Symbols_by_id:
del Symbols_by_id[id]
del Symbols[label, None]
return cls(id, label, context, kind=kind, **attributes)
id = crud.insert('symbol_table',
option='replace',
label=label,
kind=kind,
context=context and context.id,
**attributes)
return cls(id, label, context, kind=kind, **attributes)
def write(self):
r'''Update database to reflect changes on this object.
'''
if self.updated_attrs:
crud.update('symbol_table',
{'label': self.label,
'context': self.context and self.context.id},
**dict((attr, getattr(self, attr))
for attr in self.updated_attrs))
self.updated_attrs.clear()
