コード例 #1
0
    def apply(self, expr, evaluation):
        "Attributes[expr_]"

        if isinstance(expr, String):
            expr = Symbol(expr.get_string_value())
        name = expr.get_lookup_name()
        attributes = list(evaluation.definitions.get_attributes(name))
        attributes.sort()
        attr = [Symbol(attribute) for attribute in attributes]
        return Expression("List", *attr)
コード例 #2
0
    def assign_elementary(self, lhs, rhs, evaluation, tags=None, upset=False):
        name = lhs.get_head_name()

        if name in system_symbols('OwnValues', 'DownValues', 'SubValues',
                                  'UpValues', 'NValues', 'Options',
                                  'DefaultValues', 'Attributes', 'Messages'):
            if len(lhs.leaves) != 1:
                evaluation.message_args(name, len(lhs.leaves), 1)
                return False
            tag = lhs.leaves[0].get_name()
            if not tag:
                evaluation.message(name, 'sym', lhs.leaves[0], 1)
                return False
            if tags is not None and tags != [tag]:
                evaluation.message(name, 'tag', Symbol(name), Symbol(tag))
                return False

            if (name != 'System`Attributes' and 'System`Protected'  # noqa
                    in evaluation.definitions.get_attributes(tag)):
                evaluation.message(name, 'wrsym', Symbol(tag))
                return False
            if name == 'System`Options':
                option_values = rhs.get_option_values(evaluation)
                if option_values is None:
                    evaluation.message(name, 'options', rhs)
                    return False
                evaluation.definitions.set_options(tag, option_values)
            elif name == 'System`Attributes':
                attributes = get_symbol_list(
                    rhs, lambda item: evaluation.message(name, 'sym', item, 1))
                if attributes is None:
                    return False
                if 'System`Locked' in evaluation.definitions.get_attributes(
                        tag):
                    evaluation.message(name, 'locked', Symbol(tag))
                    return False
                evaluation.definitions.set_attributes(tag, attributes)
            else:
                rules = rhs.get_rules_list()
                if rules is None:
                    evaluation.message(name, 'vrule', lhs, rhs)
                    return False
                evaluation.definitions.set_values(tag, name, rules)
            return True

        form = ''
        nprec = None
        default = False
        message = False

        allow_custom_tag = False

        focus = lhs

        if name == 'System`N':
            if len(lhs.leaves) not in (1, 2):
                evaluation.message_args('N', len(lhs.leaves), 1, 2)
                return False
            if len(lhs.leaves) == 1:
                nprec = Symbol('MachinePrecision')
            else:
                nprec = lhs.leaves[1]
            focus = lhs.leaves[0]
            lhs = Expression('N', focus, nprec)
        elif name == 'System`MessageName':
            if len(lhs.leaves) != 2:
                evaluation.message_args('MessageName', len(lhs.leaves), 2)
                return False
            focus = lhs.leaves[0]
            message = True
        elif name == 'System`Default':
            if len(lhs.leaves) not in (1, 2, 3):
                evaluation.message_args('Default', len(lhs.leaves), 1, 2, 3)
                return False
            focus = lhs.leaves[0]
            default = True
        elif name == 'System`Format':
            if len(lhs.leaves) not in (1, 2):
                evaluation.message_args('Format', len(lhs.leaves), 1, 2)
                return False
            if len(lhs.leaves) == 2:
                form = lhs.leaves[1].get_name()
                if not form:
                    evaluation.message('Format', 'fttp', lhs.leaves[1])
                    return False
            else:
                form = system_symbols('StandardForm', 'TraditionalForm',
                                      'OutputForm', 'TeXForm', 'MathMLForm')
            lhs = focus = lhs.leaves[0]
        else:
            allow_custom_tag = True

        focus = focus.evaluate_leaves(evaluation)

        if tags is None and not upset:
            name = focus.get_lookup_name()
            if not name:
                evaluation.message(self.get_name(), 'setraw', focus)
                return False
            tags = [name]
        elif upset:
            if allow_custom_tag:
                tags = []
                if focus.is_atom():
                    evaluation.message(self.get_name(), 'normal')
                    return False
                for leaf in focus.leaves:
                    name = leaf.get_lookup_name()
                    tags.append(name)
            else:
                tags = [focus.get_lookup_name()]
        else:
            allowed_names = [focus.get_lookup_name()]
            if allow_custom_tag:
                for leaf in focus.get_leaves():
                    allowed_names.append(leaf.get_lookup_name())
            for name in tags:
                if name not in allowed_names:
                    evaluation.message(self.get_name(), 'tagnfd', Symbol(name))
                    return False

        ignore_protection = False
        rhs_int_value = rhs.get_int_value()
        lhs_name = lhs.get_name()
        if lhs_name == 'System`$RecursionLimit':
            # if (not rhs_int_value or rhs_int_value < 20) and not
            # rhs.get_name() == 'System`Infinity':
            if (not rhs_int_value or rhs_int_value < 20
                    or rhs_int_value > settings.MAX_RECURSION_DEPTH):  # nopep8

                evaluation.message('$RecursionLimit', 'limset', rhs)
                return False
            try:
                set_recursionlimit(rhs_int_value)
            except OverflowError:
                # TODO: Message
                return False
            ignore_protection = True
        elif lhs_name == 'System`$OutputSizeLimit':
            if rhs.to_python() == float('inf'):
                rhs = Symbol('System`Infinity')
            elif rhs_int_value is None or rhs_int_value <= 0:
                evaluation.message(lhs_name, 'intnn', rhs)
                return False
            ignore_protection = True
        elif lhs_name == 'System`$ModuleNumber':
            if not rhs_int_value or rhs_int_value <= 0:
                evaluation.message('$ModuleNumber', 'set', rhs)
                return False
            ignore_protection = True
        elif lhs_name in ('System`$Line', 'System`$HistoryLength'):
            if rhs_int_value is None or rhs_int_value < 0:
                evaluation.message(lhs_name, 'intnn', rhs)
                return False
            ignore_protection = True
        elif lhs_name == 'System`$RandomState':
            # TODO: allow setting of legal random states!
            # (but consider pickle's insecurity!)
            evaluation.message('$RandomState', 'rndst', rhs)
            return False
        elif lhs_name == 'System`$Context':
            new_context = rhs.get_string_value()
            if new_context is None or not valid_context_name(
                    new_context, allow_initial_backquote=True):
                evaluation.message(lhs_name, 'cxset', rhs)
                return False

            # With $Context in Mathematica you can do some strange
            # things: e.g. with $Context set to Global`, something
            # like:
            #    $Context = "`test`"; newsym
            # is accepted and creates Global`test`newsym.
            # Implement this behaviour by interpreting
            #    $Context = "`test`"
            # as
            #    $Context = $Context <> "test`"
            #
            if new_context.startswith('`'):
                new_context = (evaluation.definitions.get_current_context() +
                               new_context.lstrip('`'))

            evaluation.definitions.set_current_context(new_context)
            ignore_protection = True
            return True
        elif lhs_name == 'System`$ContextPath':
            context_path = [s.get_string_value() for s in rhs.get_leaves()]
            if rhs.has_form('List', None) and all(
                    valid_context_name(s) for s in context_path):
                evaluation.definitions.set_context_path(context_path)
                ignore_protection = True
                return True
            else:
                evaluation.message(lhs_name, 'cxlist', rhs)
                return False
        elif lhs_name == 'System`$MinPrecision':
            # $MinPrecision = Infinity is not allowed
            if rhs_int_value is not None and rhs_int_value >= 0:
                ignore_protection = True
                max_prec = evaluation.definitions.get_config_value(
                    '$MaxPrecision')
                if max_prec is not None and max_prec < rhs_int_value:
                    evaluation.message('$MinPrecision', 'preccon',
                                       Symbol('$MinPrecision'))
                    return True
            else:
                evaluation.message(lhs_name, 'precset', lhs, rhs)
                return False
        elif lhs_name == 'System`$MaxPrecision':
            if rhs.has_form('DirectedInfinity',
                            1) and rhs.leaves[0].get_int_value() == 1:
                ignore_protection = True
            elif rhs_int_value is not None and rhs_int_value > 0:
                ignore_protection = True
                min_prec = evaluation.definitions.get_config_value(
                    '$MinPrecision')
                if min_prec is not None and rhs_int_value < min_prec:
                    evaluation.message('$MaxPrecision', 'preccon',
                                       Symbol('$MaxPrecision'))
                    ignore_protection = True
                    return True
            else:
                evaluation.message(lhs_name, 'precset', lhs, rhs)
                return False

        rhs_name = rhs.get_head_name()
        if rhs_name == 'System`Condition':
            if len(rhs.leaves) != 2:
                evaluation.message_args('Condition', len(rhs.leaves), 2)
                return False
            else:
                lhs = Expression('Condition', lhs, rhs.leaves[1])
                rhs = rhs.leaves[0]

        rule = Rule(lhs, rhs)
        count = 0
        defs = evaluation.definitions
        for tag in tags:
            if (not ignore_protection and 'System`Protected'  # noqa
                    in evaluation.definitions.get_attributes(tag)):
                if lhs.get_name() == tag:
                    evaluation.message(self.get_name(), 'wrsym', Symbol(tag))
                else:
                    evaluation.message(self.get_name(), 'write', Symbol(tag),
                                       lhs)
                continue
            count += 1
            if form:
                defs.add_format(tag, rule, form)
            elif nprec:
                defs.add_nvalue(tag, rule)
            elif default:
                defs.add_default(tag, rule)
            elif message:
                defs.add_message(tag, rule)
            else:
                if upset:
                    defs.add_rule(tag, rule, position='up')
                else:
                    defs.add_rule(tag, rule)
        if count == 0:
            return False

        return True