def string_value(obj):
if is_tag_node(obj) or is_attribute_node(obj) or is_text_node(obj):
return derive_text_from_node(obj, peek_context().preserve_space)
elif is_number(obj) or is_boolean(obj):
return str(obj)
elif is_node_set(obj):
return string_value(obj[0]) if len(obj) > 0 else ''
elif is_sequence(obj):
return ''.join(string_value(item) for item in obj)
elif is_string(obj):
return obj
else:
raise NotImplementedError('string_value not implemented for type "{0}"'.format(obj.__class__.__name__))
def accept_context_node():
context = peek_context()
format_str = u'Evaluating predicate expression for context node at position {0} of {1}: {2}.'
verbose_print(lambda: format_str.format(context.position, context.size, debug_dump_node(context.node)))
value = expression_fn()
if is_number(value):
accept = number(context.position) == value
else:
accept = bool(value)
verbose_print(lambda: u'{0} node {1}'.format('Accepted' if accept else 'Rejected',
debug_dump_node(context.node)))
return [context.node] if accept else []
def odd():
return boolean(peek_context().position % 2 == 1)
def even():
return boolean(peek_context().position % 2 == 0)
def position():
return number(peek_context().position)
def last():
return number(peek_context().size)
def odd():
return boolean(peek_context().position % 2 == 1)
def even():
return boolean(peek_context().position % 2 == 0)