/
lexer.py
executable file
·269 lines (238 loc) · 9.01 KB
/
lexer.py
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#!/usr/bin/env python
# coding UTF-8
## Copyright 2013 Constantin Kulikov
##
## Author: Constantin Kulikov (Bad_ptr) <zxnotdead@gmail.com>
## Date: 2013/07/20 14:56:03
## License: GPL either version 2 or any later version
from typecheck import typecheck
from common_classes import (ClsShow, gen_indentation, thing_pprint
, PStringable, thing_as_string
, PLengthable, thing_as_length)
from iters_readers import (BufferedIterator
, BIReadable, BufferedReader, TextReader
, ReadResult, Nomatch, Fullmatch, Partialmatch)
from utils import (_or, get_from_nested_dict, merge_nested_dicts, set_to_nested_dict)
from collections import (deque, Iterable)
import re
def string_to_tok_by_type(string=None, tok_types=None, mode="first" #or "longer"
, only_fullmatch=True):
string = _or(string, "")
tok_types = _or(tok_types, [])
if mode == "first":
tr = TextReader(string)
for tt in tok_types:
rslt = tr.read_thing(tt)
if rslt.is_fullmatch():
return rslt.readedlist[0]
#tr.inp_buf_iter.re_iter()
return None
elif mode == "longer":
ml = -1
rt = None
tr = TextReader(string)
for tt in tok_types:
rslt = tr.read_thing(tt)
if rslt.is_fullmatch():
tok = rslt.readedlist[0]
tl = len(tok.string)
if tl > ml:
ml = tl
rt = tok
tr.inp_buf_iter.re_iter()
return rt
else:
return None
class Token(BIReadable, PStringable):
def __init__(self, string=None, Type=None):
self.string = _or(string, "")
self.type = _or(Type, TTYPE_EOF)
def __eq__(self, other):
if isinstance(other, Token):
return self.string == other.string
elif isinstance(other, TokenType):
return self.type == other
elif isinstance(other, str):
return self.string == other
else:
return False
#return self.string == thing_as_string(other)
def PPrint(self, level=0, pref="", post="", end="\n", first_indent=True):
space = gen_indentation(level)
if first_indent:
print(space, end="")
print( pref + self.__class__.__name__ + "(" + repr(self.string) + ", ", end="")
if None is self.type:
print('None', end="")
else:
print(self.type.name, end="")
#thing_pprint(self.type, end="")
print(")" + post, end=end)
def _as_string(self):
return self.string
def _read_from(self, tr, **options) -> ReadResult:
if isinstance(tr, TextReader):
rslt = tr.read_string(self.string, **options)
rslt.readed_list = [self]
rslt.readed_object = self
return rslt
elif isinstance(tr, TokenReader):
rslt = tr.read_next(**options)
if rslt.is_fullmatch():
readed_tok = rslt.readedlist[0]
if self == readed_tok:
return rslt
else:
tr.push_back(rslt.readedlist)
return Nomatch([], self)
else:
return Nomatch([] ,self)
class TokenType(BIReadable):
def __init__(self, name=None, pattern=None):
self.name = _or(name, "")
self.pattern = pattern
def _read_from(self, tr, **options) -> ReadResult:
if isinstance(tr, TextReader):
rslt = tr.read_thing(self.pattern, **options)
if rslt.is_fullmatch():
string = thing_as_string(rslt.readedlist)
rslt.readedlist = [Token(string, self)]
rslt.readed_object = self
return rslt
elif isinstance(tr, TokenReader):
rslt = tr.read_next(**options)
if rslt.is_fullmatch():
readed_tok = rslt.readedlist[0]
if readed_tok == self:
rslt.readed_object = self
return rslt
else:
tr.push_back(rslt.readedlist)
return Nomatch([], self)
else:
return Nomatch([], self)
TTYPE_EOF = TokenType("EOF", "")
TOK_EOF = Token("", TTYPE_EOF)
class TokenIterator(BufferedIterator):
def __init__(self, tr:TextReader=None, token_types=None, tokens_skip=None
, mode="first", n_prelook=25):
self.text_reader = tr
if isinstance(self.text_reader, BufferedIterator):
self.text_reader = TextReader(self.text_reader)
self.token_types = _or(token_types, [])
self.tokens_skip = _or(tokens_skip, [])
self.mode = mode # "first" or "longer"
self.n_prelook = n_prelook
self.buffer, self.backbuffer = deque([]), deque([])
self.at_end = False
def __iter__(self):
return self
def __next__(self):
if self.at_end:
raise StopIteration
ret = TOK_EOF
try:
ret = self.buffer.popleft()
except IndexError:
self.refillbuffer()
try:
ret = self.buffer.popleft()
except IndexError:
self.at_end = True
raise StopIteration
else:
self.backbuffer.append(ret)
else:
self.backbuffer.append(ret)
if ret == TOK_EOF:
self.at_end = True
if ret in self.tokens_skip:
ret = next(self)
return ret
def re_iter(self):
self.text_reader.inp_buf_iter.re_iter()
return self
def refillbuffer(self):
for n in range(self.n_prelook):
if self.mode == "first":
for tt in self.token_types:
rslt = self.text_reader.read_thing(tt)
if rslt.is_fullmatch():
self.push_forward(rslt.readedlist[0])
break
elif self.mode == "longer":
ml = -1
rt = None
for tt in self.token_types:
rslt = self.text_reader.read_thing(tt)
if rslt.is_fullmatch():
tok = rslt.readedlist[0]
tl = len(tok.string)
if tl > ml:
ml = tl
rt = tok
self.text_reader.push_back(rslt.readedlist)
if None is not rt:
rslt = self.text_reader.read_thing(rt)
if rslt.is_fullmatch():
self.push_forward(rslt.readedlist[0])
else:
break
return self
def push_forward(self, el=None):
if el is not None:
if isinstance(el, str):
tok = string_to_tok_by_type(el, self.token_types)
if None is tok:
tok = Token(el)
self.push_forward(tok)
elif isinstance(el, Iterable):
for e in el:
self.push_forward(e)
else:
self.at_end = False
self.buffer.append(el)
return self
def push_back(self, el=None):
if el is not None:
if isinstance(el, str):
tok = string_to_tok_by_type(el, self.token_types)
if None is tok:
tok = Token(el)
self.push_back(tok)
elif isinstance(el, Iterable):
seq = reversed(list(el))
for e in seq:
self.push_back(e)
else:
self.at_end = False
be = self.backbuffer.pop()
if el != be:
self.backbuffer.append(be)
self.buffer.appendleft(el)
return self
class TokenReader(BufferedReader):
def __init__(self, inp_buf_iter : TokenIterator=None, hooks=None):
super().__init__(inp_buf_iter, hooks)
if(isinstance(self.inp_buf_iter, Iterable)
and not isinstance(self.inp_buf_iter, TokenIterator)):
self.inp_buf_iter = TextReader(self.inp_buf_iter)
if isinstance(self.inp_buf_iter, TextReader):
self.inp_buf_iter = TokenIterator(self.inp_buf_iter)
def read_thing(self, thing, **options):
if isinstance(thing, (TokenType, Token, str)):
rslt = self.read_next(**options)
if rslt.is_fullmatch():
tok = rslt.readedlist[0]
if tok == thing:
return Fullmatch([tok], thing)
else:
self.push_back(rslt.readedlist)
return Nomatch([], thing)
elif isinstance(thing, BIReadable):
return thing.read_from(self, **options)
elif isinstance(thing, Iterable):
return self.read_thing_seq(thing, **options)
else:
return Nomatch([], thing)
#return self.read_thing(thing_as_string(thing), **options)