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import py
from rpython.rlib.parsing import deterministic, regex
class Token(object):
def __init__(self, name, source, source_pos):
self.name = name
self.source = source
self.source_pos = source_pos
def copy(self):
return self.__class__(self.name, self.source, self.source_pos)
def __eq__(self, other):
# for testing only
return self.__dict__ == other.__dict__
def __ne__(self, other):
# for testing only
return not self == other
def __repr__(self):
return "Token(%r, %r, %r)" % (self.name, self.source, self.source_pos)
class SourcePos(object):
"""An object to record position in source code."""
def __init__(self, i, lineno, columnno):
self.i = i # index in source string
self.lineno = lineno # line number in source
self.columnno = columnno # column in line
def copy(self):
return SourcePos(self.i, self.lineno, self.columnno)
def __eq__(self, other):
# for testing only
return self.__dict__ == other.__dict__
def __ne__(self, other):
# for testing only
return not self == other
def __repr__(self):
return "SourcePos(%r, %r, %r)" % (self.i, self.lineno, self.columnno)
class Lexer(object):
def __init__(self, token_regexs, names, ignore=None):
self.token_regexs = token_regexs
self.names = names
self.rex = regex.LexingOrExpression(token_regexs, names)
automaton = self.rex.make_automaton()
self.automaton = automaton.make_deterministic(names)
self.automaton.optimize() # XXX not sure whether this is a good idea
if ignore is None:
ignore = []
for ign in ignore:
assert ign in names
self.ignore = dict.fromkeys(ignore)
self.matcher = self.automaton.make_lexing_code()
def get_runner(self, text, eof=False, token_class=None):
return LexingDFARunner(self.matcher, self.automaton, text,
self.ignore, eof, token_class=token_class)
def tokenize(self, text, eof=False):
"""Return a list of Token's from text."""
r = self.get_runner(text, eof)
result = []
while 1:
try:
tok = r.find_next_token()
result.append(tok)
except StopIteration:
break
return result
def get_dummy_repr(self):
return '%s\nlexer = DummyLexer(recognize, %r, %r)' % (
py.code.Source(self.matcher),
self.automaton,
self.ignore)
def __getstate__(self):
return (self.token_regexs, self.names, self.ignore)
def __setstate__(self, args):
self.__init__(*args)
class DummyLexer(Lexer):
def __init__(self, matcher, automaton, ignore):
self.token_regexs = None
self.names = None
self.rex = None
self.automaton = automaton
self.ignore = ignore
self.matcher = matcher
class AbstractLexingDFARunner(deterministic.DFARunner):
i = 0
def __init__(self, matcher, automaton, text, eof=False):
self.automaton = automaton
self.state = 0
self.text = text
self.last_matched_state = 0
self.last_matched_index = -1
self.eof = eof
self.matcher = matcher
self.lineno = 0
self.columnno = 0
def find_next_token(self):
while 1:
self.state = 0
start = self.last_matched_index + 1
assert start >= 0
# Handle end of file situation
if start == len(self.text) and self.eof:
self.last_matched_index += 1
return self.make_token(start, -1, "", eof=True)
elif start >= len(self.text):
raise StopIteration
i = self.inner_loop(start)
if i < 0:
i = ~i
stop = self.last_matched_index + 1
assert stop >= 0
if start == stop:
source_pos = self.token_position_class(i - 1, self.lineno, self.columnno)
raise deterministic.LexerError(self.text, self.state,
source_pos)
source = self.text[start:stop]
result = self.make_token(start, self.last_matched_state, source)
self.adjust_position(source)
if self.ignore_token(self.last_matched_state):
continue
return result
if self.last_matched_index == i - 1:
source = self.text[start: ]
result = self.make_token(start, self.last_matched_state, source)
self.adjust_position(source)
if self.ignore_token(self.last_matched_state):
if self.eof:
self.last_matched_index += 1
return self.make_token(i, -1, "", eof=True)
else:
raise StopIteration
return result
source_pos = self.token_position_class(i - 1, self.lineno, self.columnno)
raise deterministic.LexerError(self.text, self.state, source_pos)
def adjust_position(self, token):
"""Update the line# and col# as a result of this token."""
newlines = token.count("\n")
self.lineno += newlines
if newlines==0:
self.columnno += len(token)
else:
self.columnno = token.rfind("\n")
# def inner_loop(self, i):
# while i < len(self.text):
# char = self.text[i]
# #print i, self.last_matched_index, self.last_matched_state, repr(char)
# try:
# state = self.nextstate(char)
# except KeyError:
# return ~i
# if state in self.automaton.final_states:
# self.last_matched_state = state
# self.last_matched_index = i
# i += 1
# if state not in self.automaton.final_states:
# return ~i
# return i
def inner_loop(self, i):
return self.matcher(self, i)
next = find_next_token
def __iter__(self):
return self
class LexingDFARunner(AbstractLexingDFARunner):
def __init__(self, matcher, automaton, text, ignore, eof=False,
token_class=None):
if not token_class:
self.token_class = Token
self.token_position_class = SourcePos
else:
self.token_class = token_class
self.token_position_class = token_class.source_position_class
AbstractLexingDFARunner.__init__(self, matcher, automaton, text, eof)
self.ignore = ignore
def ignore_token(self, state):
return self.automaton.names[state] in self.ignore
def make_token(self, index, state, text, eof=False):
assert (eof and state == -1) or 0 <= state < len(self.automaton.names)
source_pos = self.token_position_class(index, self.lineno, self.columnno)
if eof:
return self.token_class("EOF", "EOF", source_pos)
return self.token_class(self.automaton.names[self.last_matched_state],
text, source_pos)
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