def _check_root_elem(self, root_elem: ElementTree.Element):
"""
Check root element
:param root_elem: XML DOM root element
"""
if root_elem.tag != "program":
raise XMLFormatError(
"Vstupní XML musí mít kořenový element <program>")
has_language = False
for attrib, value in root_elem.attrib.items():
if attrib == 'language':
if value != 'IPPcode18':
raise XMLFormatError(
"Kořenový element <program> musí obsahovat atribut 'language=\"IPPcode18\"'"
)
else:
has_language = True
elif attrib not in ['name', 'description']:
raise XMLFormatError(
"Nepovolený atribut '{}' elementu '<program>".format(
attrib))
if not has_language:
raise XMLFormatError(
"Kořenový element <program> musí obsahovat atribut 'language=\"IPPcode18\"'"
)
def _check_instruction_args(self, instruction: ElementTree.Element):
"""
Check instruction arguments
:param instruction: XML DOM instruction element
"""
args = list()
opcode = instruction.attrib['opcode']
order = instruction.attrib['order']
for arg in instruction:
matches = self.arg_regex.match(arg.tag)
if matches:
nth = int(matches.group(1))
if nth in args:
raise XMLFormatError(
"Duplikátní argument {} instrukce {}".format(
arg.tag, order))
args.append(nth)
Instruction.is_valid_arg(opcode, nth, arg)
else:
raise XMLFormatError(
"Neplatný agrument {} instrukce {}".format(arg.tag, order))
if len(args) != Instruction.get_opcode_arg_num(opcode):
raise SrcSyntaxError(
"Neplatný počet argumentů instrukce {}".format(order))
for i in range(1, len(args) + 1):
if i not in args:
raise XMLFormatError(
"Chybí argument 'arg{}' v instrukci {}".format(i, order))
def _check_instruction_attribs(self, instruction: ElementTree.Element):
"""
Check instruction attributes
:param instruction: XML DOM instruction element
"""
has_opcode = has_order = False
for attrib, value in instruction.attrib.items():
if attrib == "order":
try:
int(value)
has_order = True
except ValueError:
raise LexicalError(
"Atribut 'order' neobsahuje číselnou hodnotu")
elif attrib == "opcode":
if value not in Instruction.INSTRUCTION_ARGS:
raise SrcSyntaxError(
"Neplatný operační kód '{}'".format(value))
else:
has_opcode = True
else:
raise XMLFormatError("Neznámý atribut '{}'".format(attrib))
if not has_order or not has_opcode:
raise XMLFormatError(
"Chybí atribut 'order' nebo 'opcode' v elementu <instruction>")
def parse_from_string(self, xml_string: str) -> ElementTree.Element:
"""
Parse XML from given string
:param xml_string: string with xml
:return: root XML DOM element
"""
try:
xml_dom = ElementTree.fromstring(xml_string)
except ElementTree.ParseError:
raise XMLFormatError("Vstupní XML nemá správný formát'")
self._check_xml_structure(xml_dom)
return xml_dom
def _check_instructions(self, root_elem: ElementTree.Element):
"""
Check instructions
:param root_elem: XML DOM root element
"""
for instruction in root_elem:
if instruction.tag != "instruction":
raise XMLFormatError("Neočekávaný element {}".format(
instruction.tag))
self._check_instruction_attribs(instruction)
self._check_instruction_args(instruction)
def is_valid_arg(opcode: str, nth_arg: int, arg: Element):
"""
Check if given argument in XML DOM element form is valid
:param opcode: instruction opcode (expects a valid opcode)
:param nth_arg: argument position
:param arg: XML DOM element
"""
assert opcode in Instruction.INSTRUCTION_ARGS
if not (1 <= nth_arg <= len(Instruction.INSTRUCTION_ARGS[opcode])):
raise XMLFormatError('Neplatný argument arg{}'.format(
nth_arg, opcode))
if 'type' not in arg.attrib:
raise XMLFormatError(
'Chybí atribut "type" argumentu arg{} instrukce {}'.format(
nth_arg, opcode))
if len(arg.attrib) != 1:
raise XMLFormatError(
'Neplatný počet atributů argumentu arg{} instrukce {}'.format(
nth_arg, opcode))
lexical_analyzer.check_validity(arg.attrib['type'], arg.text)
def parse_from_file(self, file: str) -> ElementTree.Element:
"""
Parse XML from given file
:param file: file with xml
:return: root XML DOM element
"""
try:
xml_dom = ElementTree.parse(file).getroot()
except ElementTree.ParseError:
raise XMLFormatError("Vstupní XML nemá správný formát'")
except FileNotFoundError:
raise ApplicationError(
"Nepodařilo se otevřít vstupní soubor '{}'".format(file),
INPUT_FILE_ERROR)
self._check_xml_structure(xml_dom)
return xml_dom