def parse(fh):
descriptor = TokenTypeDescriptorCore()
if not check(fh, "{"):
error.log("Missing opening '{' at begin of token_type definition", fh)
already_defined_list = []
position = fh.tell()
sr_begin = SourceRef.from_FileHandle(fh)
result = True
while result == True:
try:
# x = fh.tell(); fh.seek(x)
result = parse_section(fh, descriptor, already_defined_list)
except EndOfStreamException:
fh.seek(position)
error.error_eof("token_type", fh)
if not check(fh, "}"):
fh.seek(position)
error.log("Missing closing '}' at end of token_type definition.", fh);
result = TokenTypeDescriptor(descriptor, sr_begin)
if len(result.get_member_db()) == 0 \
and result.class_name == "Token" \
and result.token_id_type.sr.is_void() \
and result.column_number_type.sr.is_void() \
and result.line_number_type.sr.is_void():
error.log("Section 'token_type' does not define any members, does not\n" + \
"modify any standard member types, nor does it define a class\n" + \
"different from 'Token'.", fh)
result.consistency_check()
return result
def __parse_element(new_mode, fh):
"""Returns: False, if a closing '}' has been found.
True, else.
"""
position = fh.tell()
try:
description = "pattern or event handler"
skip_whitespace(fh)
# NOTE: Do not use 'read_word' since we need to continue directly after
# whitespace, if a regular expression is to be parsed.
position = fh.tell()
word = read_until_whitespace(fh)
if word == "}": return False
# -- check for 'on_entry', 'on_exit', ...
if __parse_event(new_mode, fh, word): return True
fh.seek(position)
description = "start of mode element: regular expression"
pattern = regular_expression.parse(fh)
pattern.set_source_reference(SourceRef.from_FileHandle(fh, new_mode.name))
position = fh.tell()
description = "start of mode element: code fragment for '%s'" % pattern.pattern_string()
__parse_action(new_mode, fh, pattern.pattern_string(), pattern)
except EndOfStreamException:
fh.seek(position)
error.error_eof(description, fh)
return True
def __parse_element(new_mode, fh):
"""Returns: False, if a closing '}' has been found.
True, else.
"""
position = fh.tell()
try:
description = "pattern or event handler"
skip_whitespace(fh)
# NOTE: Do not use 'read_word' since we need to continue directly after
# whitespace, if a regular expression is to be parsed.
position = fh.tell()
word = read_until_whitespace(fh)
if word == "}": return False
# -- check for 'on_entry', 'on_exit', ...
if __parse_event(new_mode, fh, word): return True
fh.seek(position)
description = "start of mode element: regular expression"
pattern = regular_expression.parse(fh)
pattern.set_source_reference(SourceRef.from_FileHandle(fh, new_mode.name))
position = fh.tell()
description = "start of mode element: code fragment for '%s'" % pattern.pattern_string()
__parse_action(new_mode, fh, pattern.pattern_string(), pattern)
except EndOfStreamException:
fh.seek(position)
error.error_eof(description, fh)
return True
def __parse_brief_token_sender(fh, ContinueF):
# shorthand for { self.send(TKN_SOMETHING); QUEX_SETTING_AFTER_SEND_CONTINUE_OR_RETURN(); }
position = fh.tell()
try:
skip_whitespace(fh)
position = fh.tell()
code = __parse_token_id_specification_by_character_code(fh)
if code != -1:
code = __create_token_sender_by_character_code(fh, code)
else:
skip_whitespace(fh)
identifier = __read_token_identifier(fh)
skip_whitespace(fh)
if identifier in ["GOTO", "GOSUB", "GOUP"]:
code = __create_mode_transition_and_token_sender(
fh, identifier)
else:
code = __create_token_sender_by_token_name(fh, identifier)
check_or_die(fh, ";")
if len(code) != 0:
if ContinueF:
code += "QUEX_SETTING_AFTER_SEND_CONTINUE_OR_RETURN();\n"
return CodeUser(code, SourceRef.from_FileHandle(fh))
else:
return None
except EndOfStreamException:
fh.seek(position)
error.error_eof("token", fh)
def __parse_brief_token_sender(fh, ContinueF):
# shorthand for { self.send(TKN_SOMETHING); QUEX_SETTING_AFTER_SEND_CONTINUE_OR_RETURN(); }
position = fh.tell()
try:
skip_whitespace(fh)
position = fh.tell()
code = __parse_token_id_specification_by_character_code(fh)
if code != -1:
code = __create_token_sender_by_character_code(fh, code)
else:
skip_whitespace(fh)
identifier = __read_token_identifier(fh)
skip_whitespace(fh)
if identifier in ["GOTO", "GOSUB", "GOUP"]:
code = __create_mode_transition_and_token_sender(fh, identifier)
else:
code = __create_token_sender_by_token_name(fh, identifier)
check_or_die(fh, ";")
if len(code) != 0:
if ContinueF: code += "QUEX_SETTING_AFTER_SEND_CONTINUE_OR_RETURN();\n"
return CodeUser(code, SourceRef.from_FileHandle(fh))
else:
return None
except EndOfStreamException:
fh.seek(position)
error.error_eof("token", fh)
def parse_section(fh, descriptor, already_defined_list):
pos = fh.tell()
try:
return __parse_section(fh, descriptor, already_defined_list)
except EndOfStreamException:
fh.seek(pos)
error.error_eof("token_type", fh)
def parse_standard_members(fh, section_name, descriptor, already_defined_list):
if not check(fh, "{"):
error.log("Missing opening '{' at begin of token_type section '%s'." % section_name, fh);
position = fh.tell()
while 1 + 1 == 2:
try:
result = parse_variable_definition(fh)
except EndOfStreamException:
fh.seek(position)
error.error_eof("standard", fh)
if result is None: return
type_code_fragment, name = result[0], result[1]
__validate_definition(type_code_fragment, name,
already_defined_list, StandardMembersF=True)
if name == "id": descriptor.token_id_type = type_code_fragment
elif name == "column_number": descriptor.column_number_type = type_code_fragment
elif name == "line_number": descriptor.line_number_type = type_code_fragment
else:
assert False # This should have been caught by the variable parser function
already_defined_list.append([name, type_code_fragment])
def __parse_element(new_mode, fh):
"""Returns: False, if a closing '}' has been found.
True, else.
"""
position = fh.tell()
try:
description = "pattern or event handler"
skip_whitespace(fh)
# NOTE: Do not use 'read_word' since we need to continue directly after
# whitespace, if a regular expression is to be parsed.
position = fh.tell()
identifier = read_identifier(fh)
if identifier == "keyword_list":
return __parse_keyword_list(new_mode, fh)
elif similarity.get(identifier, ["keyword_list", "key words"]) != -1:
error.warning(
"'%s' is similar to keyword 'keyword_list'.\n"
"For clarity, use quotes." % identifier, fh)
elif identifier == "brief":
return __parse_brief(new_mode, fh)
elif similarity.get(identifier,
["brief", "briefing", "briefly"]) != -1:
error.warning(
"'%s' is similar to keyword 'brief'.\n"
"For clarity, use quotes." % identifier, fh)
fh.seek(position)
word = read_until_whitespace(fh)
if word == "}":
return False
# -- check for 'on_entry', 'on_exit', ...
elif __parse_event(new_mode, fh, word):
return True
fh.seek(position)
description = "start of mode element: regular expression"
pattern = regular_expression.parse(fh)
pattern.set_source_reference(
SourceRef.from_FileHandle(fh, new_mode.name))
position = fh.tell()
description = "start of mode element: code fragment for '%s'" % pattern.pattern_string(
)
__parse_action(new_mode, fh, pattern.pattern_string(), pattern)
except EndOfStreamException:
fh.seek(position)
error.error_eof(description, fh)
return True
def __parse_option_list(new_mode, fh):
position = fh.tell()
try:
# ':' => inherited modes/option_db follow
skip_whitespace(fh)
__parse_base_mode_list(fh, new_mode)
while mode_option.parse(fh, new_mode):
pass
except EndOfStreamException:
fh.seek(position)
error.error_eof("mode '%s'." % new_mode.name, fh)
def __parse_option_list(new_mode, fh):
position = fh.tell()
try:
# ':' => inherited modes/option_db follow
skip_whitespace(fh)
__parse_base_mode_list(fh, new_mode)
while mode_option.parse(fh, new_mode):
pass
except EndOfStreamException:
fh.seek(position)
error.error_eof("mode '%s'." % new_mode.name, fh)
def parse_variable_definition_list(fh,
SectionName,
already_defined_list,
GroupF=False):
position = fh.tell()
db = OrderedDict() # See comment [MEMBER PACKAGING]
while 1 + 1 == 2:
try:
result = parse_variable_definition(
fh, GroupF=True, already_defined_list=already_defined_list)
except EndOfStreamException:
fh.seek(position)
error.error_eof(SectionName, fh)
if result is None:
return db
# The type_descriptor can be:
# -- a UserCodeFragment with a string of the type
# -- a dictionary that contains the combined variable definitions.
type_descriptor = result[0]
# If only one argument was returned it was a 'struct' that requires
# an implicit definition of the struct that combines the variables.
if len(result) == 1:
name = "data_" + repr(data_name_index_counter_get())
else:
name = result[1]
db[name] = type_descriptor
if len(result) == 1:
assert isinstance(type_descriptor, OrderedDict)
# In case of a 'combined' definition each variable needs to be validated.
for sub_name, sub_type in type_descriptor.items():
__validate_definition(sub_type,
sub_type,
already_defined_list,
StandardMembersF=False)
already_defined_list.append([sub_name, sub_type])
else:
assert type_descriptor.__class__ == CodeUser
__validate_definition(type_descriptor,
name,
already_defined_list,
StandardMembersF=False)
already_defined_list.append([name, type_descriptor])
def __parse_action(new_mode, fh, pattern_str, pattern):
position = fh.tell()
try:
skip_whitespace(fh)
position = fh.tell()
code = code_fragment.parse(fh,
"regular expression",
ErrorOnFailureF=False)
if code is not None:
assert isinstance(code, CodeUser), "Found: %s" % code.__class__
new_mode.add_pattern_action_pair(pattern, code, fh)
return
fh.seek(position)
word = read_until_letter(fh, [";"])
if word == "PRIORITY-MARK":
# This mark 'lowers' the priority of a pattern to the priority of the current
# pattern index (important for inherited patterns, that have higher precedence).
# The parser already constructed a state machine for the pattern that is to
# be assigned a new priority. Since, this machine is not used, let us just
# use its id.
fh.seek(-1, 1)
check_or_die(fh, ";",
". Since quex version 0.33.5 this is required.")
new_mode.add_match_priority(pattern, fh)
elif word == "DELETION":
# This mark deletes any pattern that was inherited with the same 'name'
fh.seek(-1, 1)
check_or_die(fh, ";",
". Since quex version 0.33.5 this is required.")
new_mode.add_match_deletion(pattern, fh)
else:
error.log("Missing token '{', 'PRIORITY-MARK', 'DELETION', or '=>' after '%s'.\n" % pattern_str + \
"found: '%s'. Note, that since quex version 0.33.5 it is required to add a ';'\n" % word + \
"to the commands PRIORITY-MARK and DELETION.", fh)
except EndOfStreamException:
fh.seek(position)
error.error_eof("pattern action", fh)
def __parse_function_argument_list(fh, ReferenceName):
argument_list = []
position = fh.tell()
try:
# Read argument list
if check(fh, "(") == False:
return []
text = ""
while 1 + 1 == 2:
tmp = fh.read(1)
if tmp == ")":
break
elif tmp in ["(", "[", "{"]:
closing_bracket = {"(": ")", "[": "]", "{": "}"}[tmp]
text += tmp + read_until_closing_bracket(
fh, tmp, closing_bracket) + closing_bracket
elif tmp == "\"":
text += tmp + read_until_closing_bracket(
fh, "", "\"", IgnoreRegions=[]) + "\""
elif tmp == "'":
text += tmp + read_until_closing_bracket(
fh, "", "'", IgnoreRegions=[]) + "'"
elif tmp == ",":
argument_list.append(text)
text = ""
elif tmp == "":
fh.seek(position)
error.error_eof("argument list for %s" % ReferenceName, fh)
else:
text += tmp
if text != "": argument_list.append(text)
argument_list = map(lambda arg: arg.strip(), argument_list)
argument_list = filter(lambda arg: arg != "", argument_list)
return argument_list
except EndOfStreamException:
fh.seek(position)
error.error_eof("token", fh)
def __parse_action(new_mode, fh, pattern_str, pattern):
position = fh.tell()
try:
skip_whitespace(fh)
position = fh.tell()
code = code_fragment.parse(fh, "regular expression", ErrorOnFailureF=False)
if code is not None:
assert isinstance(code, CodeUser), "Found: %s" % code.__class__
new_mode.add_pattern_action_pair(pattern, code, fh)
return
fh.seek(position)
word = read_until_letter(fh, [";"])
if word == "PRIORITY-MARK":
# This mark 'lowers' the priority of a pattern to the priority of the current
# pattern index (important for inherited patterns, that have higher precedence).
# The parser already constructed a state machine for the pattern that is to
# be assigned a new priority. Since, this machine is not used, let us just
# use its id.
fh.seek(-1, 1)
check_or_die(fh, ";", ". Since quex version 0.33.5 this is required.")
new_mode.add_match_priority(pattern, fh)
elif word == "DELETION":
# This mark deletes any pattern that was inherited with the same 'name'
fh.seek(-1, 1)
check_or_die(fh, ";", ". Since quex version 0.33.5 this is required.")
new_mode.add_match_deletion(pattern, fh)
else:
error.log("Missing token '{', 'PRIORITY-MARK', 'DELETION', or '=>' after '%s'.\n" % pattern_str + \
"found: '%s'. Note, that since quex version 0.33.5 it is required to add a ';'\n" % word + \
"to the commands PRIORITY-MARK and DELETION.", fh)
except EndOfStreamException:
fh.seek(position)
error.error_eof("pattern action", fh)
def __parse_function_argument_list(fh, ReferenceName):
argument_list = []
position = fh.tell()
try:
# Read argument list
if check(fh, "(") == False:
return []
text = ""
while 1 + 1 == 2:
tmp = fh.read(1)
if tmp == ")":
break
elif tmp in ["(", "[", "{"]:
closing_bracket = {"(": ")", "[": "]", "{": "}"}[tmp]
text += tmp + read_until_closing_bracket(fh, tmp, closing_bracket) + closing_bracket
elif tmp == "\"":
text += tmp + read_until_closing_bracket(fh, "", "\"", IgnoreRegions = []) + "\""
elif tmp == "'":
text += tmp + read_until_closing_bracket(fh, "", "'", IgnoreRegions = []) + "'"
elif tmp == ",":
argument_list.append(text)
text = ""
elif tmp == "":
fh.seek(position)
error.error_eof("argument list for %s" % ReferenceName, fh)
else:
text += tmp
if text != "": argument_list.append(text)
argument_list = map(lambda arg: arg.strip(), argument_list)
argument_list = filter(lambda arg: arg != "", argument_list)
return argument_list
except EndOfStreamException:
fh.seek(position)
error.error_eof("token", fh)
def __parse_brief_token_sender(fh):
# shorthand for { self.send(TKN_SOMETHING); RETURN; }
position = fh.tell()
try:
skip_whitespace(fh)
position = fh.tell()
code = __parse_token_id_specification_by_character_code(fh)
if code != -1:
code = __create_token_sender_by_character_code(fh, code)
else:
skip_whitespace(fh)
identifier = __read_token_identifier(fh)
skip_whitespace(fh)
if identifier in ["GOTO", "GOSUB", "GOUP"]:
code = __create_mode_transition_and_token_sender(
fh, identifier)
else:
code = __create_token_sender_by_token_name(fh, identifier)
check_or_die(fh, ";")
if code:
# IMPORTANT: For handlers 'on_end_of_stream' and 'on_failure',
# => CONTINUE would be desastrous!
# -- When a termination token is sent, no other token shall follow.
# Return MUST be enforced => Do not allow CONTINUE!
# -- When an 'on_failure' is detected allow immediate action of the
# receiver. => Do not allow CONTINUE!
code += "\n%s\n" % Lng.PURE_RETURN # Immediate RETURN after token sending
return CodeUser(code,
SourceRef.from_FileHandle(fh, BeginPos=position))
else:
return None
except EndOfStreamException:
fh.seek(position)
error.error_eof("token", fh)
def parse_section(fh):
global default_token_type_definition_triggered_by_mode_definition_f
# NOTE: End of File is supposed to be reached when trying to read a new
# section. Thus, the end-of-file catcher does not encompass the beginning.
position = fh.tell()
skip_whitespace(fh)
word = read_identifier(fh, OnMissingStr="Missing section title")
error.verify_word_in_list(word, blackboard.all_section_title_list,
"Unknown quex section '%s'" % word, fh)
try:
# (*) determine what is defined
#
# -- 'mode { ... }' => define a mode
# -- 'start = ...;' => define the name of the initial mode
# -- 'header { ... }' => define code that is to be pasted on top
# of the engine (e.g. "#include<...>")
# -- 'body { ... }' => define code that is to be pasted in the class' body
# of the engine (e.g. "public: int my_member;")
# -- 'init { ... }' => define code that is to be pasted in the class' constructors
# of the engine (e.g. "my_member = -1;")
# -- 'define { ... }' => define patterns shorthands such as IDENTIFIER for [a-z]+
# -- 'repeated_token_id = QUEX_TKN_ ...;' => enables token repetition, defines
# the token id to be repeated.
# -- 'token { ... }' => define token ids
# -- 'token_type { ... }' => define a customized token type
#
if word in blackboard.fragment_db.keys():
element_name = blackboard.fragment_db[word]
fragment = code_fragment.parse(fh,
word,
AllowBriefTokenSenderF=False)
blackboard.__dict__[element_name] = fragment
return
elif word == "start":
mode_name = parse_identifier_assignment(fh)
if mode_name == "":
error.log("Missing mode_name after 'start ='", fh)
elif not blackboard.initial_mode.sr.is_void():
error.log("start mode defined more than once!",
fh,
DontExitF=True)
error.log("previously defined here",
blackboard.initial_mode.sr)
blackboard.initial_mode = CodeUser(mode_name,
SourceRef.from_FileHandle(fh))
return
elif word == "repeated_token":
blackboard.token_repetition_token_id_list = parse_token_id_definitions(
fh, NamesOnlyF=True)
for token_name in blackboard.token_repetition_token_id_list:
error.verify_word_in_list(
token_name[len(Setup.token_id_prefix):],
blackboard.token_id_db.keys(),
"Token ID '%s' not yet defined." % token_name,
fh,
ExitF=False,
SuppressCode=NotificationDB.
warning_repeated_token_not_yet_defined)
return
elif word == "define":
parse_pattern_name_definitions(fh)
return
elif word == "token":
if Setup.token_id_foreign_definition:
error.log("Token id file '%s' has been specified.\n" \
% Setup.token_id_foreign_definition_file \
+ "All token ids must be specified there. Section 'token'\n" \
+ "is not allowed.", fh)
parse_token_id_definitions(fh)
return
elif word == "token_type":
if Setup.token_class_file != "":
error.log("Section 'token_type' is intended to generate a token class.\n" \
+ "However, the manually written token class file '%s'" \
% repr(Setup.token_class_file) \
+ "has been specified on the command line.",
fh)
if blackboard.token_type_definition is None:
blackboard.token_type_definition = token_type.parse(fh)
return
# Error case:
if default_token_type_definition_triggered_by_mode_definition_f:
error.log(
"Section 'token_type' must appear before first mode definition.",
fh)
else:
error.log("Section 'token_type' has been defined twice.",
fh,
DontExitF=True)
error.log("Previously defined here.",
blackboard.token_type_definition.sr)
return
elif word == "mode":
# When the first mode is parsed then a token_type definition must be
# present. If not, the default token type definition is considered.
if blackboard.token_type_definition is None:
parse_default_token_definition()
default_token_type_definition_triggered_by_mode_definition_f = True
mode.parse(fh)
return
else:
# This case should have been caught by the 'verify_word_in_list' function
assert False
except EndOfStreamException:
fh.seek(position)
error.error_eof(word, fh)
def parse_section(fh):
global default_token_type_definition_triggered_by_mode_definition_f
# NOTE: End of File is supposed to be reached when trying to read a new
# section. Thus, the end-of-file catcher does not encompass the beginning.
position = fh.tell()
skip_whitespace(fh)
word = read_identifier(fh, OnMissingStr="Missing section title")
error.verify_word_in_list(word, blackboard.all_section_title_list,
"Unknown quex section '%s'" % word, fh)
try:
# (*) determine what is defined
#
# -- 'mode { ... }' => define a mode
# -- 'start = ...;' => define the name of the initial mode
# -- 'header { ... }' => define code that is to be pasted on top
# of the engine (e.g. "#include<...>")
# -- 'body { ... }' => define code that is to be pasted in the class' body
# of the engine (e.g. "public: int my_member;")
# -- 'init { ... }' => define code that is to be pasted in the class' constructors
# of the engine (e.g. "my_member = -1;")
# -- 'define { ... }' => define patterns shorthands such as IDENTIFIER for [a-z]+
# -- 'repeated_token_id = QUEX_TKN_ ...;' => enables token repetition, defines
# the token id to be repeated.
# -- 'token { ... }' => define token ids
# -- 'token_type { ... }' => define a customized token type
#
if word in blackboard.fragment_db.keys():
element_name = blackboard.fragment_db[word]
fragment = code_fragment.parse(fh, word, AllowBriefTokenSenderF=False)
blackboard.__dict__[element_name] = fragment
return
elif word == "start":
mode_name = parse_identifier_assignment(fh)
if mode_name == "":
error.log("Missing mode_name after 'start ='", fh)
elif not blackboard.initial_mode.sr.is_void():
error.log("start mode defined more than once!", fh, DontExitF=True)
error.log("previously defined here", blackboard.initial_mode.sr)
blackboard.initial_mode = CodeUser(mode_name, SourceRef.from_FileHandle(fh))
return
elif word == "repeated_token":
blackboard.token_repetition_token_id_list = parse_token_id_definitions(fh, NamesOnlyF=True)
for token_name in blackboard.token_repetition_token_id_list:
error.verify_word_in_list(token_name[len(Setup.token_id_prefix):],
blackboard.token_id_db.keys(),
"Token ID '%s' not yet defined." % token_name, fh,
ExitF=False,
SuppressCode=NotificationDB.warning_repeated_token_not_yet_defined)
return
elif word == "define":
parse_pattern_name_definitions(fh)
return
elif word == "token":
if Setup.token_id_foreign_definition:
error.log("Token id file '%s' has been specified.\n" \
% Setup.token_id_foreign_definition_file \
+ "All token ids must be specified there. Section 'token'\n" \
+ "is not allowed.", fh)
parse_token_id_definitions(fh)
return
elif word == "token_type":
if Setup.token_class_file != "":
error.log("Section 'token_type' is intended to generate a token class.\n" \
+ "However, the manually written token class file '%s'" \
% repr(Setup.token_class_file) \
+ "has been specified on the command line.",
fh)
if blackboard.token_type_definition is None:
blackboard.token_type_definition = token_type.parse(fh)
return
# Error case:
if default_token_type_definition_triggered_by_mode_definition_f:
error.log("Section 'token_type' must appear before first mode definition.",
fh)
else:
error.log("Section 'token_type' has been defined twice.",
fh, DontExitF=True)
error.log("Previously defined here.",
blackboard.token_type_definition.sr)
return
elif word == "mode":
# When the first mode is parsed then a token_type definition must be
# present. If not, the default token type definition is considered.
if blackboard.token_type_definition is None:
parse_default_token_definition()
default_token_type_definition_triggered_by_mode_definition_f = True
mode.parse(fh)
return
else:
# This case should have been caught by the 'verify_word_in_list' function
assert False
except EndOfStreamException:
fh.seek(position)
error.error_eof(word, fh)
sh = StringIO(Txt_or_File)
# (*) Parse the pattern => A Pattern object
start_position = sh.tell()
try:
pattern = regex.do(sh, blackboard.shorthand_db,
AllowNothingIsNecessaryF = AllowNothingIsFineF,
SpecialTerminator = Terminator)
except RegularExpressionException, x:
sh.seek(start_position)
error.log("Regular expression parsing:\n" + x.message, sh)
except EndOfStreamException:
sh.seek(start_position)
error.error_eof("regular expression", sh)
# (*) Extract the object as required
if ExtractFunction is not None:
result = ExtractFunction(pattern.sm)
if pattern.has_pre_or_post_context() or result is None:
sh.seek(start_position)
pattern_str = pattern.pattern_string().strip()
txt = "Regular expression '%s' cannot be interpreted as plain %s." % (pattern_str, Name)
if len(pattern_str) != 0 and pattern_str[-1] == Terminator:
txt += "\nMissing delimiting whitespace ' ' between the regular expression and '%s'.\n" % Terminator
error.log(txt, sh)
else:
result = None
