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Diffstat (limited to 'src/ply/lex.py')
| -rw-r--r-- | src/ply/lex.py | 901 |
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diff --git a/src/ply/lex.py b/src/ply/lex.py new file mode 100644 index 0000000..de011fe --- /dev/null +++ b/src/ply/lex.py @@ -0,0 +1,901 @@ +# ----------------------------------------------------------------------------- +# ply: lex.py +# +# Copyright (C) 2001-2022 +# David M. Beazley (Dabeaz LLC) +# All rights reserved. +# +# Latest version: https://github.com/dabeaz/ply +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright notice, +# this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright notice, +# this list of conditions and the following disclaimer in the documentation +# and/or other materials provided with the distribution. +# * Neither the name of David Beazley or Dabeaz LLC may be used to +# endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# ----------------------------------------------------------------------------- + +import re +import sys +import types +import copy +import os +import inspect + +# This tuple contains acceptable string types +StringTypes = (str, bytes) + +# This regular expression is used to match valid token names +_is_identifier = re.compile(r'^[a-zA-Z0-9_]+$') + +# Exception thrown when invalid token encountered and no default error +# handler is defined. +class LexError(Exception): + def __init__(self, message, s): + self.args = (message,) + self.text = s + +# Token class. This class is used to represent the tokens produced. +class LexToken(object): + def __repr__(self): + return f'LexToken({self.type},{self.value!r},{self.lineno},{self.lexpos})' + +# This object is a stand-in for a logging object created by the +# logging module. + +class PlyLogger(object): + def __init__(self, f): + self.f = f + + def critical(self, msg, *args, **kwargs): + self.f.write((msg % args) + '\n') + + def warning(self, msg, *args, **kwargs): + self.f.write('WARNING: ' + (msg % args) + '\n') + + def error(self, msg, *args, **kwargs): + self.f.write('ERROR: ' + (msg % args) + '\n') + + info = critical + debug = critical + +# ----------------------------------------------------------------------------- +# === Lexing Engine === +# +# The following Lexer class implements the lexer runtime. There are only +# a few public methods and attributes: +# +# input() - Store a new string in the lexer +# token() - Get the next token +# clone() - Clone the lexer +# +# lineno - Current line number +# lexpos - Current position in the input string +# ----------------------------------------------------------------------------- + +class Lexer: + def __init__(self): + self.lexre = None # Master regular expression. This is a list of + # tuples (re, findex) where re is a compiled + # regular expression and findex is a list + # mapping regex group numbers to rules + self.lexretext = None # Current regular expression strings + self.lexstatere = {} # Dictionary mapping lexer states to master regexs + self.lexstateretext = {} # Dictionary mapping lexer states to regex strings + self.lexstaterenames = {} # Dictionary mapping lexer states to symbol names + self.lexstate = 'INITIAL' # Current lexer state + self.lexstatestack = [] # Stack of lexer states + self.lexstateinfo = None # State information + self.lexstateignore = {} # Dictionary of ignored characters for each state + self.lexstateerrorf = {} # Dictionary of error functions for each state + self.lexstateeoff = {} # Dictionary of eof functions for each state + self.lexreflags = 0 # Optional re compile flags + self.lexdata = None # Actual input data (as a string) + self.lexpos = 0 # Current position in input text + self.lexlen = 0 # Length of the input text + self.lexerrorf = None # Error rule (if any) + self.lexeoff = None # EOF rule (if any) + self.lextokens = None # List of valid tokens + self.lexignore = '' # Ignored characters + self.lexliterals = '' # Literal characters that can be passed through + self.lexmodule = None # Module + self.lineno = 1 # Current line number + + def clone(self, object=None): + c = copy.copy(self) + + # If the object parameter has been supplied, it means we are attaching the + # lexer to a new object. In this case, we have to rebind all methods in + # the lexstatere and lexstateerrorf tables. + + if object: + newtab = {} + for key, ritem in self.lexstatere.items(): + newre = [] + for cre, findex in ritem: + newfindex = [] + for f in findex: + if not f or not f[0]: + newfindex.append(f) + continue + newfindex.append((getattr(object, f[0].__name__), f[1])) + newre.append((cre, newfindex)) + newtab[key] = newre + c.lexstatere = newtab + c.lexstateerrorf = {} + for key, ef in self.lexstateerrorf.items(): + c.lexstateerrorf[key] = getattr(object, ef.__name__) + c.lexmodule = object + return c + + # ------------------------------------------------------------ + # input() - Push a new string into the lexer + # ------------------------------------------------------------ + def input(self, s): + self.lexdata = s + self.lexpos = 0 + self.lexlen = len(s) + + # ------------------------------------------------------------ + # begin() - Changes the lexing state + # ------------------------------------------------------------ + def begin(self, state): + if state not in self.lexstatere: + raise ValueError(f'Undefined state {state!r}') + self.lexre = self.lexstatere[state] + self.lexretext = self.lexstateretext[state] + self.lexignore = self.lexstateignore.get(state, '') + self.lexerrorf = self.lexstateerrorf.get(state, None) + self.lexeoff = self.lexstateeoff.get(state, None) + self.lexstate = state + + # ------------------------------------------------------------ + # push_state() - Changes the lexing state and saves old on stack + # ------------------------------------------------------------ + def push_state(self, state): + self.lexstatestack.append(self.lexstate) + self.begin(state) + + # ------------------------------------------------------------ + # pop_state() - Restores the previous state + # ------------------------------------------------------------ + def pop_state(self): + self.begin(self.lexstatestack.pop()) + + # ------------------------------------------------------------ + # current_state() - Returns the current lexing state + # ------------------------------------------------------------ + def current_state(self): + return self.lexstate + + # ------------------------------------------------------------ + # skip() - Skip ahead n characters + # ------------------------------------------------------------ + def skip(self, n): + self.lexpos += n + + # ------------------------------------------------------------ + # token() - Return the next token from the Lexer + # + # Note: This function has been carefully implemented to be as fast + # as possible. Don't make changes unless you really know what + # you are doing + # ------------------------------------------------------------ + def token(self): + # Make local copies of frequently referenced attributes + lexpos = self.lexpos + lexlen = self.lexlen + lexignore = self.lexignore + lexdata = self.lexdata + + while lexpos < lexlen: + # This code provides some short-circuit code for whitespace, tabs, and other ignored characters + if lexdata[lexpos] in lexignore: + lexpos += 1 + continue + + # Look for a regular expression match + for lexre, lexindexfunc in self.lexre: + m = lexre.match(lexdata, lexpos) + if not m: + continue + + # Create a token for return + tok = LexToken() + tok.value = m.group() + tok.lineno = self.lineno + tok.lexpos = lexpos + + i = m.lastindex + func, tok.type = lexindexfunc[i] + + if not func: + # If no token type was set, it's an ignored token + if tok.type: + self.lexpos = m.end() + return tok + else: + lexpos = m.end() + break + + lexpos = m.end() + + # If token is processed by a function, call it + + tok.lexer = self # Set additional attributes useful in token rules + self.lexmatch = m + self.lexpos = lexpos + newtok = func(tok) + del tok.lexer + del self.lexmatch + + # Every function must return a token, if nothing, we just move to next token + if not newtok: + lexpos = self.lexpos # This is here in case user has updated lexpos. + lexignore = self.lexignore # This is here in case there was a state change + break + return newtok + else: + # No match, see if in literals + if lexdata[lexpos] in self.lexliterals: + tok = LexToken() + tok.value = lexdata[lexpos] + tok.lineno = self.lineno + tok.type = tok.value + tok.lexpos = lexpos + self.lexpos = lexpos + 1 + return tok + + # No match. Call t_error() if defined. + if self.lexerrorf: + tok = LexToken() + tok.value = self.lexdata[lexpos:] + tok.lineno = self.lineno + tok.type = 'error' + tok.lexer = self + tok.lexpos = lexpos + self.lexpos = lexpos + newtok = self.lexerrorf(tok) + if lexpos == self.lexpos: + # Error method didn't change text position at all. This is an error. + raise LexError(f"Scanning error. Illegal character {lexdata[lexpos]!r}", + lexdata[lexpos:]) + lexpos = self.lexpos + if not newtok: + continue + return newtok + + self.lexpos = lexpos + raise LexError(f"Illegal character {lexdata[lexpos]!r} at index {lexpos}", + lexdata[lexpos:]) + + if self.lexeoff: + tok = LexToken() + tok.type = 'eof' + tok.value = '' + tok.lineno = self.lineno + tok.lexpos = lexpos + tok.lexer = self + self.lexpos = lexpos + newtok = self.lexeoff(tok) + return newtok + + self.lexpos = lexpos + 1 + if self.lexdata is None: + raise RuntimeError('No input string given with input()') + return None + + # Iterator interface + def __iter__(self): + return self + + def __next__(self): + t = self.token() + if t is None: + raise StopIteration + return t + +# ----------------------------------------------------------------------------- +# ==== Lex Builder === +# +# The functions and classes below are used to collect lexing information +# and build a Lexer object from it. +# ----------------------------------------------------------------------------- + +# ----------------------------------------------------------------------------- +# _get_regex(func) +# +# Returns the regular expression assigned to a function either as a doc string +# or as a .regex attribute attached by the @TOKEN decorator. +# ----------------------------------------------------------------------------- +def _get_regex(func): + return getattr(func, 'regex', func.__doc__) + +# ----------------------------------------------------------------------------- +# get_caller_module_dict() +# +# This function returns a dictionary containing all of the symbols defined within +# a caller further down the call stack. This is used to get the environment +# associated with the yacc() call if none was provided. +# ----------------------------------------------------------------------------- +def get_caller_module_dict(levels): + f = sys._getframe(levels) + return { **f.f_globals, **f.f_locals } + +# ----------------------------------------------------------------------------- +# _form_master_re() +# +# This function takes a list of all of the regex components and attempts to +# form the master regular expression. Given limitations in the Python re +# module, it may be necessary to break the master regex into separate expressions. +# ----------------------------------------------------------------------------- +def _form_master_re(relist, reflags, ldict, toknames): + if not relist: + return [], [], [] + regex = '|'.join(relist) + try: + lexre = re.compile(regex, reflags) + + # Build the index to function map for the matching engine + lexindexfunc = [None] * (max(lexre.groupindex.values()) + 1) + lexindexnames = lexindexfunc[:] + + for f, i in lexre.groupindex.items(): + handle = ldict.get(f, None) + if type(handle) in (types.FunctionType, types.MethodType): + lexindexfunc[i] = (handle, toknames[f]) + lexindexnames[i] = f + elif handle is not None: + lexindexnames[i] = f + if f.find('ignore_') > 0: + lexindexfunc[i] = (None, None) + else: + lexindexfunc[i] = (None, toknames[f]) + + return [(lexre, lexindexfunc)], [regex], [lexindexnames] + except Exception: + m = (len(relist) // 2) + 1 + llist, lre, lnames = _form_master_re(relist[:m], reflags, ldict, toknames) + rlist, rre, rnames = _form_master_re(relist[m:], reflags, ldict, toknames) + return (llist+rlist), (lre+rre), (lnames+rnames) + +# ----------------------------------------------------------------------------- +# def _statetoken(s,names) +# +# Given a declaration name s of the form "t_" and a dictionary whose keys are +# state names, this function returns a tuple (states,tokenname) where states +# is a tuple of state names and tokenname is the name of the token. For example, +# calling this with s = "t_foo_bar_SPAM" might return (('foo','bar'),'SPAM') +# ----------------------------------------------------------------------------- +def _statetoken(s, names): + parts = s.split('_') + for i, part in enumerate(parts[1:], 1): + if part not in names and part != 'ANY': + break + + if i > 1: + states = tuple(parts[1:i]) + else: + states = ('INITIAL',) + + if 'ANY' in states: + states = tuple(names) + + tokenname = '_'.join(parts[i:]) + return (states, tokenname) + + +# ----------------------------------------------------------------------------- +# LexerReflect() +# +# This class represents information needed to build a lexer as extracted from a +# user's input file. +# ----------------------------------------------------------------------------- +class LexerReflect(object): + def __init__(self, ldict, log=None, reflags=0): + self.ldict = ldict + self.error_func = None + self.tokens = [] + self.reflags = reflags + self.stateinfo = {'INITIAL': 'inclusive'} + self.modules = set() + self.error = False + self.log = PlyLogger(sys.stderr) if log is None else log + + # Get all of the basic information + def get_all(self): + self.get_tokens() + self.get_literals() + self.get_states() + self.get_rules() + + # Validate all of the information + def validate_all(self): + self.validate_tokens() + self.validate_literals() + self.validate_rules() + return self.error + + # Get the tokens map + def get_tokens(self): + tokens = self.ldict.get('tokens', None) + if not tokens: + self.log.error('No token list is defined') + self.error = True + return + + if not isinstance(tokens, (list, tuple)): + self.log.error('tokens must be a list or tuple') + self.error = True + return + + if not tokens: + self.log.error('tokens is empty') + self.error = True + return + + self.tokens = tokens + + # Validate the tokens + def validate_tokens(self): + terminals = {} + for n in self.tokens: + if not _is_identifier.match(n): + self.log.error(f"Bad token name {n!r}") + self.error = True + if n in terminals: + self.log.warning(f"Token {n!r} multiply defined") + terminals[n] = 1 + + # Get the literals specifier + def get_literals(self): + self.literals = self.ldict.get('literals', '') + if not self.literals: + self.literals = '' + + # Validate literals + def validate_literals(self): + try: + for c in self.literals: + if not isinstance(c, StringTypes) or len(c) > 1: + self.log.error(f'Invalid literal {c!r}. Must be a single character') + self.error = True + + except TypeError: + self.log.error('Invalid literals specification. literals must be a sequence of characters') + self.error = True + + def get_states(self): + self.states = self.ldict.get('states', None) + # Build statemap + if self.states: + if not isinstance(self.states, (tuple, list)): + self.log.error('states must be defined as a tuple or list') + self.error = True + else: + for s in self.states: + if not isinstance(s, tuple) or len(s) != 2: + self.log.error("Invalid state specifier %r. Must be a tuple (statename,'exclusive|inclusive')", s) + self.error = True + continue + name, statetype = s + if not isinstance(name, StringTypes): + self.log.error('State name %r must be a string', name) + self.error = True + continue + if not (statetype == 'inclusive' or statetype == 'exclusive'): + self.log.error("State type for state %r must be 'inclusive' or 'exclusive'", name) + self.error = True + continue + if name in self.stateinfo: + self.log.error("State %r already defined", name) + self.error = True + continue + self.stateinfo[name] = statetype + + # Get all of the symbols with a t_ prefix and sort them into various + # categories (functions, strings, error functions, and ignore characters) + + def get_rules(self): + tsymbols = [f for f in self.ldict if f[:2] == 't_'] + + # Now build up a list of functions and a list of strings + self.toknames = {} # Mapping of symbols to token names + self.funcsym = {} # Symbols defined as functions + self.strsym = {} # Symbols defined as strings + self.ignore = {} # Ignore strings by state + self.errorf = {} # Error functions by state + self.eoff = {} # EOF functions by state + + for s in self.stateinfo: + self.funcsym[s] = [] + self.strsym[s] = [] + + if len(tsymbols) == 0: + self.log.error('No rules of the form t_rulename are defined') + self.error = True + return + + for f in tsymbols: + t = self.ldict[f] + states, tokname = _statetoken(f, self.stateinfo) + self.toknames[f] = tokname + + if hasattr(t, '__call__'): + if tokname == 'error': + for s in states: + self.errorf[s] = t + elif tokname == 'eof': + for s in states: + self.eoff[s] = t + elif tokname == 'ignore': + line = t.__code__.co_firstlineno + file = t.__code__.co_filename + self.log.error("%s:%d: Rule %r must be defined as a string", file, line, t.__name__) + self.error = True + else: + for s in states: + self.funcsym[s].append((f, t)) + elif isinstance(t, StringTypes): + if tokname == 'ignore': + for s in states: + self.ignore[s] = t + if '\\' in t: + self.log.warning("%s contains a literal backslash '\\'", f) + + elif tokname == 'error': + self.log.error("Rule %r must be defined as a function", f) + self.error = True + else: + for s in states: + self.strsym[s].append((f, t)) + else: + self.log.error('%s not defined as a function or string', f) + self.error = True + + # Sort the functions by line number + for f in self.funcsym.values(): + f.sort(key=lambda x: x[1].__code__.co_firstlineno) + + # Sort the strings by regular expression length + for s in self.strsym.values(): + s.sort(key=lambda x: len(x[1]), reverse=True) + + # Validate all of the t_rules collected + def validate_rules(self): + for state in self.stateinfo: + # Validate all rules defined by functions + + for fname, f in self.funcsym[state]: + line = f.__code__.co_firstlineno + file = f.__code__.co_filename + module = inspect.getmodule(f) + self.modules.add(module) + + tokname = self.toknames[fname] + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = f.__code__.co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule %r has too many arguments", file, line, f.__name__) + self.error = True + continue + + if nargs < reqargs: + self.log.error("%s:%d: Rule %r requires an argument", file, line, f.__name__) + self.error = True + continue + + if not _get_regex(f): + self.log.error("%s:%d: No regular expression defined for rule %r", file, line, f.__name__) + self.error = True + continue + + try: + c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), self.reflags) + if c.match(''): + self.log.error("%s:%d: Regular expression for rule %r matches empty string", file, line, f.__name__) + self.error = True + except re.error as e: + self.log.error("%s:%d: Invalid regular expression for rule '%s'. %s", file, line, f.__name__, e) + if '#' in _get_regex(f): + self.log.error("%s:%d. Make sure '#' in rule %r is escaped with '\\#'", file, line, f.__name__) + self.error = True + + # Validate all rules defined by strings + for name, r in self.strsym[state]: + tokname = self.toknames[name] + if tokname == 'error': + self.log.error("Rule %r must be defined as a function", name) + self.error = True + continue + + if tokname not in self.tokens and tokname.find('ignore_') < 0: + self.log.error("Rule %r defined for an unspecified token %s", name, tokname) + self.error = True + continue + + try: + c = re.compile('(?P<%s>%s)' % (name, r), self.reflags) + if (c.match('')): + self.log.error("Regular expression for rule %r matches empty string", name) + self.error = True + except re.error as e: + self.log.error("Invalid regular expression for rule %r. %s", name, e) + if '#' in r: + self.log.error("Make sure '#' in rule %r is escaped with '\\#'", name) + self.error = True + + if not self.funcsym[state] and not self.strsym[state]: + self.log.error("No rules defined for state %r", state) + self.error = True + + # Validate the error function + efunc = self.errorf.get(state, None) + if efunc: + f = efunc + line = f.__code__.co_firstlineno + file = f.__code__.co_filename + module = inspect.getmodule(f) + self.modules.add(module) + + if isinstance(f, types.MethodType): + reqargs = 2 + else: + reqargs = 1 + nargs = f.__code__.co_argcount + if nargs > reqargs: + self.log.error("%s:%d: Rule %r has too many arguments", file, line, f.__name__) + self.error = True + + if nargs < reqargs: + self.log.error("%s:%d: Rule %r requires an argument", file, line, f.__name__) + self.error = True + + for module in self.modules: + self.validate_module(module) + + # ----------------------------------------------------------------------------- + # validate_module() + # + # This checks to see if there are duplicated t_rulename() functions or strings + # in the parser input file. This is done using a simple regular expression + # match on each line in the source code of the given module. + # ----------------------------------------------------------------------------- + + def validate_module(self, module): + try: + lines, linen = inspect.getsourcelines(module) + except IOError: + return + + fre = re.compile(r'\s*def\s+(t_[a-zA-Z_0-9]*)\(') + sre = re.compile(r'\s*(t_[a-zA-Z_0-9]*)\s*=') + + counthash = {} + linen += 1 + for line in lines: + m = fre.match(line) + if not m: + m = sre.match(line) + if m: + name = m.group(1) + prev = counthash.get(name) + if not prev: + counthash[name] = linen + else: + filename = inspect.getsourcefile(module) + self.log.error('%s:%d: Rule %s redefined. Previously defined on line %d', filename, linen, name, prev) + self.error = True + linen += 1 + +# ----------------------------------------------------------------------------- +# lex(module) +# +# Build all of the regular expression rules from definitions in the supplied module +# ----------------------------------------------------------------------------- +def lex(*, module=None, object=None, debug=False, + reflags=int(re.VERBOSE), debuglog=None, errorlog=None): + + global lexer + + ldict = None + stateinfo = {'INITIAL': 'inclusive'} + lexobj = Lexer() + global token, input + + if errorlog is None: + errorlog = PlyLogger(sys.stderr) + + if debug: + if debuglog is None: + debuglog = PlyLogger(sys.stderr) + + # Get the module dictionary used for the lexer + if object: + module = object + + # Get the module dictionary used for the parser + if module: + _items = [(k, getattr(module, k)) for k in dir(module)] + ldict = dict(_items) + # If no __file__ attribute is available, try to obtain it from the __module__ instead + if '__file__' not in ldict: + ldict['__file__'] = sys.modules[ldict['__module__']].__file__ + else: + ldict = get_caller_module_dict(2) + + # Collect parser information from the dictionary + linfo = LexerReflect(ldict, log=errorlog, reflags=reflags) + linfo.get_all() + if linfo.validate_all(): + raise SyntaxError("Can't build lexer") + + # Dump some basic debugging information + if debug: + debuglog.info('lex: tokens = %r', linfo.tokens) + debuglog.info('lex: literals = %r', linfo.literals) + debuglog.info('lex: states = %r', linfo.stateinfo) + + # Build a dictionary of valid token names + lexobj.lextokens = set() + for n in linfo.tokens: + lexobj.lextokens.add(n) + + # Get literals specification + if isinstance(linfo.literals, (list, tuple)): + lexobj.lexliterals = type(linfo.literals[0])().join(linfo.literals) + else: + lexobj.lexliterals = linfo.literals + + lexobj.lextokens_all = lexobj.lextokens | set(lexobj.lexliterals) + + # Get the stateinfo dictionary + stateinfo = linfo.stateinfo + + regexs = {} + # Build the master regular expressions + for state in stateinfo: + regex_list = [] + + # Add rules defined by functions first + for fname, f in linfo.funcsym[state]: + regex_list.append('(?P<%s>%s)' % (fname, _get_regex(f))) + if debug: + debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", fname, _get_regex(f), state) + + # Now add all of the simple rules + for name, r in linfo.strsym[state]: + regex_list.append('(?P<%s>%s)' % (name, r)) + if debug: + debuglog.info("lex: Adding rule %s -> '%s' (state '%s')", name, r, state) + + regexs[state] = regex_list + + # Build the master regular expressions + + if debug: + debuglog.info('lex: ==== MASTER REGEXS FOLLOW ====') + + for state in regexs: + lexre, re_text, re_names = _form_master_re(regexs[state], reflags, ldict, linfo.toknames) + lexobj.lexstatere[state] = lexre + lexobj.lexstateretext[state] = re_text + lexobj.lexstaterenames[state] = re_names + if debug: + for i, text in enumerate(re_text): + debuglog.info("lex: state '%s' : regex[%d] = '%s'", state, i, text) + + # For inclusive states, we need to add the regular expressions from the INITIAL state + for state, stype in stateinfo.items(): + if state != 'INITIAL' and stype == 'inclusive': + lexobj.lexstatere[state].extend(lexobj.lexstatere['INITIAL']) + lexobj.lexstateretext[state].extend(lexobj.lexstateretext['INITIAL']) + lexobj.lexstaterenames[state].extend(lexobj.lexstaterenames['INITIAL']) + + lexobj.lexstateinfo = stateinfo + lexobj.lexre = lexobj.lexstatere['INITIAL'] + lexobj.lexretext = lexobj.lexstateretext['INITIAL'] + lexobj.lexreflags = reflags + + # Set up ignore variables + lexobj.lexstateignore = linfo.ignore + lexobj.lexignore = lexobj.lexstateignore.get('INITIAL', '') + + # Set up error functions + lexobj.lexstateerrorf = linfo.errorf + lexobj.lexerrorf = linfo.errorf.get('INITIAL', None) + if not lexobj.lexerrorf: + errorlog.warning('No t_error rule is defined') + + # Set up eof functions + lexobj.lexstateeoff = linfo.eoff + lexobj.lexeoff = linfo.eoff.get('INITIAL', None) + + # Check state information for ignore and error rules + for s, stype in stateinfo.items(): + if stype == 'exclusive': + if s not in linfo.errorf: + errorlog.warning("No error rule is defined for exclusive state %r", s) + if s not in linfo.ignore and lexobj.lexignore: + errorlog.warning("No ignore rule is defined for exclusive state %r", s) + elif stype == 'inclusive': + if s not in linfo.errorf: + linfo.errorf[s] = linfo.errorf.get('INITIAL', None) + if s not in linfo.ignore: + linfo.ignore[s] = linfo.ignore.get('INITIAL', '') + + # Create global versions of the token() and input() functions + token = lexobj.token + input = lexobj.input + lexer = lexobj + + return lexobj + +# ----------------------------------------------------------------------------- +# runmain() +# +# This runs the lexer as a main program +# ----------------------------------------------------------------------------- + +def runmain(lexer=None, data=None): + if not data: + try: + filename = sys.argv[1] + with open(filename) as f: + data = f.read() + except IndexError: + sys.stdout.write('Reading from standard input (type EOF to end):\n') + data = sys.stdin.read() + + if lexer: + _input = lexer.input + else: + _input = input + _input(data) + if lexer: + _token = lexer.token + else: + _token = token + + while True: + tok = _token() + if not tok: + break + sys.stdout.write(f'({tok.type},{tok.value!r},{tok.lineno},{tok.lexpos})\n') + +# ----------------------------------------------------------------------------- +# @TOKEN(regex) +# +# This decorator function can be used to set the regex expression on a function +# when its docstring might need to be set in an alternative way +# ----------------------------------------------------------------------------- + +def TOKEN(r): + def set_regex(f): + if hasattr(r, '__call__'): + f.regex = _get_regex(r) + else: + f.regex = r + return f + return set_regex |