# -----------------------------------------------------------------------------
# ply: lex.py
#
# Copyright (C) 2001-2015,
# David M. Beazley (Dabeaz LLC)
# All rights reserved.
#
# 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 the 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.
# -----------------------------------------------------------------------------
__version__ = '3.8'
__tabversion__ = '3.8'
import re
import sys
import types
import copy
import os
import inspect
# This tuple contains known string types
try:
# Python 2.6
StringTypes = (types.StringType, types.UnicodeType)
except AttributeError:
# Python 3.0
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.
[docs]class LexError(Exception):
[docs] def __init__(self, message, s):
self.args = (message,)
self.text = s
# Token class. This class is used to represent the tokens produced.
[docs]class LexToken(object):
[docs] def __str__(self):
return 'LexToken(%s,%r,%d,%d)' % (self.type, self.value, self.lineno, self.lexpos)
[docs] def __repr__(self):
return str(self)
# This object is a stand-in for a logging object created by the
# logging module.
[docs]class PlyLogger(object):
[docs] def __init__(self, f):
self.f = f
[docs] def critical(self, msg, *args, **kwargs):
self.f.write((msg % args) + '\n')
[docs] def warning(self, msg, *args, **kwargs):
self.f.write('WARNING: ' + (msg % args) + '\n')
[docs] def error(self, msg, *args, **kwargs):
self.f.write('ERROR: ' + (msg % args) + '\n')
info = critical
debug = critical
# Null logger is used when no output is generated. Does nothing.
[docs]class NullLogger(object):
[docs] def __getattribute__(self, name):
return self
[docs] def __call__(self, *args, **kwargs):
return self
# -----------------------------------------------------------------------------
# === 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
# -----------------------------------------------------------------------------
[docs]class Lexer:
[docs] 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
self.lexoptimize = False # Optimized mode
[docs] 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
# ------------------------------------------------------------
# writetab() - Write lexer information to a table file
# ------------------------------------------------------------
[docs] def writetab(self, lextab, outputdir=''):
if isinstance(lextab, types.ModuleType):
raise IOError("Won't overwrite existing lextab module")
basetabmodule = lextab.split('.')[-1]
filename = os.path.join(outputdir, basetabmodule) + '.py'
with open(filename, 'w') as tf:
tf.write('# %s.py. This file automatically created by PLY (version %s). Don\'t edit!\n' % (basetabmodule, __version__))
tf.write('_tabversion = %s\n' % repr(__tabversion__))
tf.write('_lextokens = set(%s)\n' % repr(tuple(self.lextokens)))
tf.write('_lexreflags = %s\n' % repr(self.lexreflags))
tf.write('_lexliterals = %s\n' % repr(self.lexliterals))
tf.write('_lexstateinfo = %s\n' % repr(self.lexstateinfo))
# Rewrite the lexstatere table, replacing function objects with function names
tabre = {}
for statename, lre in self.lexstatere.items():
titem = []
for (pat, func), retext, renames in zip(lre, self.lexstateretext[statename], self.lexstaterenames[statename]):
titem.append((retext, _funcs_to_names(func, renames)))
tabre[statename] = titem
tf.write('_lexstatere = %s\n' % repr(tabre))
tf.write('_lexstateignore = %s\n' % repr(self.lexstateignore))
taberr = {}
for statename, ef in self.lexstateerrorf.items():
taberr[statename] = ef.__name__ if ef else None
tf.write('_lexstateerrorf = %s\n' % repr(taberr))
tabeof = {}
for statename, ef in self.lexstateeoff.items():
tabeof[statename] = ef.__name__ if ef else None
tf.write('_lexstateeoff = %s\n' % repr(tabeof))
# ------------------------------------------------------------
# readtab() - Read lexer information from a tab file
# ------------------------------------------------------------
[docs] def readtab(self, tabfile, fdict):
if isinstance(tabfile, types.ModuleType):
lextab = tabfile
else:
exec('import %s' % tabfile)
lextab = sys.modules[tabfile]
if getattr(lextab, '_tabversion', '0.0') != __tabversion__:
raise ImportError('Inconsistent PLY version')
self.lextokens = lextab._lextokens
self.lexreflags = lextab._lexreflags
self.lexliterals = lextab._lexliterals
self.lextokens_all = self.lextokens | set(self.lexliterals)
self.lexstateinfo = lextab._lexstateinfo
self.lexstateignore = lextab._lexstateignore
self.lexstatere = {}
self.lexstateretext = {}
for statename, lre in lextab._lexstatere.items():
titem = []
txtitem = []
for pat, func_name in lre:
titem.append((re.compile(pat, lextab._lexreflags | re.VERBOSE), _names_to_funcs(func_name, fdict)))
self.lexstatere[statename] = titem
self.lexstateretext[statename] = txtitem
self.lexstateerrorf = {}
for statename, ef in lextab._lexstateerrorf.items():
self.lexstateerrorf[statename] = fdict[ef]
self.lexstateeoff = {}
for statename, ef in lextab._lexstateeoff.items():
self.lexstateeoff[statename] = fdict[ef]
self.begin('INITIAL')
# ------------------------------------------------------------
# input() - Push a new string into the lexer
# ------------------------------------------------------------
# Pull off the first character to see if s looks like a string
c = s[:1]
if not isinstance(c, StringTypes):
raise ValueError('Expected a string')
self.lexdata = s
self.lexpos = 0
self.lexlen = len(s)
# ------------------------------------------------------------
# begin() - Changes the lexing state
# ------------------------------------------------------------
[docs] def begin(self, state):
if state not in self.lexstatere:
raise ValueError('Undefined state')
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
# ------------------------------------------------------------
[docs] def push_state(self, state):
self.lexstatestack.append(self.lexstate)
self.begin(state)
# ------------------------------------------------------------
# pop_state() - Restores the previous state
# ------------------------------------------------------------
[docs] def pop_state(self):
self.begin(self.lexstatestack.pop())
# ------------------------------------------------------------
# current_state() - Returns the current lexing state
# ------------------------------------------------------------
[docs] def current_state(self):
return self.lexstate
# ------------------------------------------------------------
# skip() - Skip ahead n characters
# ------------------------------------------------------------
[docs] def skip(self, n):
self.lexpos += n
# ------------------------------------------------------------
# opttoken() - 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
# ------------------------------------------------------------
# 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)
# 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
# Verify type of the token. If not in the token map, raise an error
if not self.lexoptimize:
if newtok.type not in self.lextokens_all:
raise LexError("%s:%d: Rule '%s' returned an unknown token type '%s'" % (
func.__code__.co_filename, func.__code__.co_firstlineno,
func.__name__, newtok.type), lexdata[lexpos:])
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("Scanning error. Illegal character '%s'" % (lexdata[lexpos]), lexdata[lexpos:])
lexpos = self.lexpos
if not newtok:
continue
return newtok
self.lexpos = lexpos
raise LexError("Illegal character '%s' at index %d" % (lexdata[lexpos], 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
[docs] def __iter__(self):
return self
[docs] def next(self):
t = self.token()
if t is None:
raise StopIteration
return t
__next__ = next
# -----------------------------------------------------------------------------
# ==== 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.
# -----------------------------------------------------------------------------
[docs]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.
# -----------------------------------------------------------------------------
[docs]def get_caller_module_dict(levels):
f = sys._getframe(levels)
ldict = f.f_globals.copy()
if f.f_globals != f.f_locals:
ldict.update(f.f_locals)
return ldict
# -----------------------------------------------------------------------------
# _funcs_to_names()
#
# Given a list of regular expression functions, this converts it to a list
# suitable for output to a table file
# -----------------------------------------------------------------------------
[docs]def _funcs_to_names(funclist, namelist):
result = []
for f, name in zip(funclist, namelist):
if f and f[0]:
result.append((name, f[1]))
else:
result.append(f)
return result
# -----------------------------------------------------------------------------
# _names_to_funcs()
#
# Given a list of regular expression function names, this converts it back to
# functions.
# -----------------------------------------------------------------------------
[docs]def _names_to_funcs(namelist, fdict):
result = []
for n in namelist:
if n and n[0]:
result.append((fdict[n[0]], n[1]))
else:
result.append(n)
return result
# -----------------------------------------------------------------------------
# _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 _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')
# -----------------------------------------------------------------------------
[docs]def _statetoken(s, names):
nonstate = 1
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.
# -----------------------------------------------------------------------------
[docs]class LexerReflect(object):
[docs] 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
[docs] def get_all(self):
self.get_tokens()
self.get_literals()
self.get_states()
self.get_rules()
# Validate all of the information
[docs] def validate_all(self):
self.validate_tokens()
self.validate_literals()
self.validate_rules()
return self.error
# Get the tokens map
[docs] 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
[docs] def validate_tokens(self):
terminals = {}
for n in self.tokens:
if not _is_identifier.match(n):
self.log.error("Bad token name '%s'", n)
self.error = True
if n in terminals:
self.log.warning("Token '%s' multiply defined", n)
terminals[n] = 1
# Get the literals specifier
[docs] def get_literals(self):
self.literals = self.ldict.get('literals', '')
if not self.literals:
self.literals = ''
# Validate literals
[docs] def validate_literals(self):
try:
for c in self.literals:
if not isinstance(c, StringTypes) or len(c) > 1:
self.log.error('Invalid literal %s. Must be a single character', repr(c))
self.error = True
except TypeError:
self.log.error('Invalid literals specification. literals must be a sequence of characters')
self.error = True
[docs] 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 %s. Must be a tuple (statename,'exclusive|inclusive')", repr(s))
self.error = True
continue
name, statetype = s
if not isinstance(name, StringTypes):
self.log.error('State name %s must be a string', repr(name))
self.error = True
continue
if not (statetype == 'inclusive' or statetype == 'exclusive'):
self.log.error("State type for state %s must be 'inclusive' or 'exclusive'", name)
self.error = True
continue
if name in self.stateinfo:
self.log.error("State '%s' 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)
[docs] 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 '%s' 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 '%s' 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
[docs] 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 '%s' has too many arguments", file, line, f.__name__)
self.error = True
continue
if nargs < reqargs:
self.log.error("%s:%d: Rule '%s' 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 '%s'", file, line, f.__name__)
self.error = True
continue
try:
c = re.compile('(?P<%s>%s)' % (fname, _get_regex(f)), re.VERBOSE | self.reflags)
if c.match(''):
self.log.error("%s:%d: Regular expression for rule '%s' 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 '%s' 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 '%s' 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 '%s' defined for an unspecified token %s", name, tokname)
self.error = True
continue
try:
c = re.compile('(?P<%s>%s)' % (name, r), re.VERBOSE | self.reflags)
if (c.match('')):
self.log.error("Regular expression for rule '%s' matches empty string", name)
self.error = True
except re.error as e:
self.log.error("Invalid regular expression for rule '%s'. %s", name, e)
if '#' in r:
self.log.error("Make sure '#' in rule '%s' 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 '%s'", 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 '%s' has too many arguments", file, line, f.__name__)
self.error = True
if nargs < reqargs:
self.log.error("%s:%d: Rule '%s' 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.
# -----------------------------------------------------------------------------
[docs] def validate_module(self, module):
lines, linen = inspect.getsourcelines(module)
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
# -----------------------------------------------------------------------------
[docs]def lex(module=None, object=None, debug=False, optimize=False, lextab='lextab',
reflags=0, nowarn=False, outputdir=None, debuglog=None, errorlog=None):
if lextab is None:
lextab = 'lextab'
global lexer
ldict = None
stateinfo = {'INITIAL': 'inclusive'}
lexobj = Lexer()
lexobj.lexoptimize = optimize
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)
# Determine if the module is package of a package or not.
# If so, fix the tabmodule setting so that tables load correctly
pkg = ldict.get('__package__')
if pkg and isinstance(lextab, str):
if '.' not in lextab:
lextab = pkg + '.' + lextab
# Collect parser information from the dictionary
linfo = LexerReflect(ldict, log=errorlog, reflags=reflags)
linfo.get_all()
if not optimize:
if linfo.validate_all():
raise SyntaxError("Can't build lexer")
if optimize and lextab:
try:
lexobj.readtab(lextab, ldict)
token = lexobj.token
input = lexobj.input
lexer = lexobj
return lexobj
except ImportError:
pass
# 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]:
line = f.__code__.co_firstlineno
file = f.__code__.co_filename
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 '%s'", s)
if s not in linfo.ignore and lexobj.lexignore:
errorlog.warning("No ignore rule is defined for exclusive state '%s'", 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
# If in optimize mode, we write the lextab
if lextab and optimize:
if outputdir is None:
# If no output directory is set, the location of the output files
# is determined according to the following rules:
# - If lextab specifies a package, files go into that package directory
# - Otherwise, files go in the same directory as the specifying module
if isinstance(lextab, types.ModuleType):
srcfile = lextab.__file__
else:
if '.' not in lextab:
srcfile = ldict['__file__']
else:
parts = lextab.split('.')
pkgname = '.'.join(parts[:-1])
exec('import %s' % pkgname)
srcfile = getattr(sys.modules[pkgname], '__file__', '')
outputdir = os.path.dirname(srcfile)
try:
lexobj.writetab(lextab, outputdir)
except IOError as e:
errorlog.warning("Couldn't write lextab module %r. %s" % (lextab, e))
return lexobj
# -----------------------------------------------------------------------------
# runmain()
#
# This runs the lexer as a main program
# -----------------------------------------------------------------------------
[docs]def runmain(lexer=None, data=None):
if not data:
try:
filename = sys.argv[1]
f = open(filename)
data = f.read()
f.close()
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('(%s,%r,%d,%d)\n' % (tok.type, tok.value, tok.lineno, tok.lexpos))
# -----------------------------------------------------------------------------
# @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
# -----------------------------------------------------------------------------
[docs]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
# Alternative spelling of the TOKEN decorator
Token = TOKEN