def set_iteration_expression(self, variable_name, expression_fn):
if self.sequence_expression is not None:
raise HquerySyntaxError(
'More than one "for" clause found in FLWOR "{0}"'.format(
self.debug_dump()))
self.sequence_variable = variable_name
self.sequence_expression = expression_fn
def __init__(self, first_axis, first_node_test, first_predicates, absolute=False, root_expression=None):
self.absolute = absolute
self.root_expression = root_expression
self.steps = []
self.append_step(first_axis, first_node_test, first_predicates)
if self.absolute and self.root_expression is not None:
raise HquerySyntaxError('internal error forming location path; it looks both rooted and absolute')
def _evaluate_unary_operand(self, operand_generator, constructor=lambda v: v, type_name='xpath object'):
try:
self._gab('evaluating operand.', indent_after=True)
operand_value = constructor(operand_generator())
self._gab('operand evaluation complete', outdent_before=True)
return operand_value
except TypeError:
raise HquerySyntaxError('evaluated against a non-{0} operand'.format(type_name))
def __init__(self, op):
if op == '>':
self.base_op = gt
elif op == '>=':
self.base_op = ge
elif op == '<':
self.base_op = lt
elif op == '<=':
self.base_op = le
else:
raise HquerySyntaxError('unexpected relational operator "{0}"'.format(op))
def nud(self):
if self.value != '-':
raise HquerySyntaxError('unexpected {0} at beginning of an expression')
right = self.parse_interface.expression(LBP.prefix_op)
def evaluate():
right_value = self._evaluate_unary_operand(right, constructor=number, type_name='number')
result = -right_value
self._gab('returning {0}'.format(result))
return result
return evaluate
def set_filters(self, source):
while len(source) > 0:
match = None
for regex, constructor in _filter_map.items():
match = re.match(regex, source)
if match:
filter_fn = constructor(
*_skip_over_embedded_groups_from_list_matches(
match.groups()))
self.filters.append(filter_fn)
source = source[match.span()[1]:]
break
if match is None:
raise HquerySyntaxError(
'Malformed filter "{0}" in computed JSON hash constructor filter clause'
.format(source))
def _evaluate_binary_operands(self,
left_generator,
right_generator,
constructor=lambda v: v,
type_name='xpath object'):
try:
self._gab('operator evaluation...', indent_after=True)
self._gab('evaluating left-hand side.', indent_after=True)
left_value = constructor(left_generator())
self._gab('evaluating right-hand side.', outdent_before=True, indent_after=True)
right_value = constructor(right_generator())
self._gab('operand evaluation complete', outdent_before=True)
self._gab('evaluating expression {0} {1} {2}'.format(left_value, self, right_value), outdent_before=True)
return left_value, right_value
except TypeError:
raise HquerySyntaxError('evaluated against a non-{0} operand'.format(type_name))
def _regex_replace_filter_link(arguments):
if arguments is None or len(arguments) < 2:
msg = 'interpolated string regex replace filter expects three arguments; got {0}'
raise HquerySyntaxError(msg.format(arguments))
if len(arguments) == 3:
flags = _xpath_flags_to_re_flags(arguments[2])
else:
flags = 0
def construct(eval_fn):
def evaluate():
value = eval_fn()
if is_sequence(value):
return [re.sub(arguments[0], arguments[1], string_value(item), flags=flags) for item in value]
else:
return re.sub(arguments[0], arguments[1], string_value(value), flags=flags)
return evaluate
return construct
def append_step(self, axis, node_test, predicates):
if axis == Axis.css_class and not node_test.is_name_test:
raise HquerySyntaxError('CSS class axis must be followed by a name test, not a node test')
self.steps.append(LocationPathStep(axis, node_test, predicates))
def set_content(self, expression_fn):
if self.contents is not None:
raise HquerySyntaxError(
'Computed attribute constructor already has contents')
self.contents = expression_fn
def set_contents(self, expression_fn):
if self.contents is not None:
raise HquerySyntaxError(
'computed JSON array constructor already has contents')
self.contents = expression_fn
def set_return_expression(self, expression_fn):
if self.return_expression is not None:
raise HquerySyntaxError(
'More than one return clause found for FLWOR {0}'.format(
self.debug_dump()))
self.return_expression = expression_fn