def templatize_rule(block, rule, index_set):
import pyomo.core.base.set
context = _template_iter_context()
internal_error = None
_old_iters = (
pyomo.core.base.set._FiniteSetMixin.__iter__,
GetItemExpression.__iter__,
GetAttrExpression.__iter__,
)
_old_sum = builtins.sum
try:
# Override Set iteration to return IndexTemplates
pyomo.core.base.set._FiniteSetMixin.__iter__ \
= GetItemExpression.__iter__ \
= GetAttrExpression.__iter__ \
= lambda x: context.get_iter(x).__iter__()
# Override sum with our sum
builtins.sum = context.sum_template
# Get the index templates needed for calling the rule
if index_set is not None:
if not index_set.isfinite():
raise TemplateExpressionError(
None,
"Cannot templatize rule with non-finite indexing set")
indices = next(iter(index_set))
try:
context.cache.pop()
except IndexError:
assert indices is None
indices = ()
else:
indices = ()
if type(indices) is not tuple:
indices = (indices, )
# Call the rule, returning the template expression and the
# top-level IndexTemplate(s) generated when calling the rule.
#
# TBD: Should this just return a "FORALL()" expression node that
# behaves similarly to the GetItemExpression node?
return rule(block, *indices), indices
except:
internal_error = sys.exc_info()
raise
finally:
pyomo.core.base.set._FiniteSetMixin.__iter__, \
GetItemExpression.__iter__, \
GetAttrExpression.__iter__ = _old_iters
builtins.sum = _old_sum
if len(context.cache):
if internal_error is not None:
logger.error("The following exception was raised when "
"templatizing the rule '%s':\n\t%s" %
(rule.__name__, internal_error[1]))
raise TemplateExpressionError(
None,
"Explicit iteration (for loops) over Sets is not supported "
"by template expressions. Encountered loop over %s" %
(context.cache[-1][0]._set, ))
return None, indices
def __call__(self, exception=True):
"""
Return the value of this object.
"""
if self._value is None:
if exception:
raise TemplateExpressionError(self)
return None
else:
return self._value
def __call__(self, exception=True):
"""
Return the value of this object.
"""
if self._value is _NotSpecified:
if exception:
raise TemplateExpressionError(
self,
"Evaluating uninitialized IndexTemplate (%s)" % (self, ))
return None
else:
return self._value