| # coding: utf-8 |
| """Attribute scoping support for symbolic API.""" |
| from __future__ import absolute_import |
| |
| from .base import string_types |
| |
| class AttrScope(object): |
| """Attribute manager for scoping. |
| |
| User can also inherit this object to change naming behavior. |
| |
| Parameters |
| ---------- |
| kwargs |
| The attributes to set for all symbol creations in the scope. |
| """ |
| current = None |
| |
| def __init__(self, **kwargs): |
| self._old_scope = None |
| for value in kwargs.values(): |
| if not isinstance(value, string_types): |
| raise ValueError("Attributes need to be string") |
| self._attr = kwargs |
| |
| def get(self, attr): |
| """ |
| Get the attribute dict given the attribute set by the symbol. |
| |
| Parameters |
| ---------- |
| attr : dict of string to string |
| The attribute passed in by user during symbol creation. |
| |
| Returns |
| ------- |
| attr : dict of string to string |
| Updated attributes to add other scope related attributes. |
| """ |
| if self._attr: |
| ret = self._attr.copy() |
| if attr: |
| ret.update(attr) |
| return ret |
| else: |
| return attr if attr else {} |
| |
| def __enter__(self): |
| # pylint: disable=protected-access |
| self._old_scope = AttrScope.current |
| attr = AttrScope.current._attr.copy() |
| attr.update(self._attr) |
| self._attr = attr |
| AttrScope.current = self |
| return self |
| |
| def __exit__(self, ptype, value, trace): |
| assert self._old_scope |
| AttrScope.current = self._old_scope |
| |
| AttrScope.current = AttrScope() |
