cpython/Doc/partparse.py

#
# partparse.py: parse a by-Guido-written-and-by-Jan-Hein-edited LaTeX file,
#     and generate texinfo source.
#
# This is *not* a good example of good programming practices. In fact, this
#     file could use a complete rewrite, in order to become faster, more
#     easy extensible and maintainable.
#
# However, I added some comments on a few places for the pityful person who
#     would ever need to take a look into this file.
#
# Have I been clear enough??
#
# -jh


import sys, string, regex, getopt, os

# Different parse modes for phase 1
MODE_REGULAR = 0
MODE_VERBATIM = 1
MODE_CS_SCAN = 2
MODE_COMMENT = 3
MODE_MATH = 4
MODE_DMATH = 5
MODE_GOBBLEWHITE = 6

the_modes = MODE_REGULAR, MODE_VERBATIM, MODE_CS_SCAN, MODE_COMMENT, \
	  MODE_MATH, MODE_DMATH, MODE_GOBBLEWHITE

# Show the neighbourhood of the scanned buffer
def epsilon(buf, where):
	wmt, wpt = where - 10, where + 10
	if wmt < 0:
		wmt = 0
	if wpt > len(buf):
		wpt = len(buf)
	return ' Context ' + `buf[wmt:where]` + '.' + `buf[where:wpt]` + '.'

# Should return the line number. never worked
def lin():
	global lineno
	return ' Line ' + `lineno` + '.'

# Displays the recursion level.
def lv(lvl):
	return ' Level ' + `lvl` + '.'

# Combine the three previous functions. Used often.
def lle(lvl, buf, where):
	return lv(lvl) + lin() + epsilon(buf, where)
	
	
# This class is only needed for _symbolic_ representation of the parse mode.
class Mode:
	def init(self, arg):
		if arg not in the_modes:
			raise ValueError, 'mode not in the_modes'
		self.mode = arg
		return self

	def __cmp__(self, other):
		if type(self) != type(other):
			other = mode(other)
		return cmp(self.mode, other.mode)

	def __repr__(self):
		if self.mode == MODE_REGULAR:
			return 'MODE_REGULAR'
		elif self.mode == MODE_VERBATIM:
			return 'MODE_VERBATIM'
		elif self.mode == MODE_CS_SCAN:
			return 'MODE_CS_SCAN'
		elif self.mode == MODE_COMMENT:
			return 'MODE_COMMENT'
		elif self.mode == MODE_MATH:
			return 'MODE_MATH'
		elif self.mode == MODE_DMATH:
			return 'MODE_DMATH'
		elif self.mode == MODE_GOBBLEWHITE:
			return 'MODE_GOBBLEWHITE'
		else:
			raise ValueError, 'mode not in the_modes'

# just a wrapper around a class initialisation
def mode(arg):
	return Mode().init(arg)


# After phase 1, the text consists of chunks, with a certain type
# this type will be assigned to the chtype member of the chunk
# the where-field contains the file position where this is found
# and the data field contains (1): a tuple describing start- end end
# positions of the substring (can be used as slice for the buf-variable),
# (2) just a string, mostly generated by the changeit routine,
# or (3) a list, describing a (recursive) subgroup of chunks
PLAIN = 0			# ASSUME PLAINTEXT, data = the text
GROUP = 1			# GROUP ({}), data = [chunk, chunk,..]
CSNAME = 2			# CONTROL SEQ TOKEN, data = the command
COMMENT = 3			# data is the actual comment
DMATH = 4			# DISPLAYMATH, data = [chunk, chunk,..]
MATH = 5			# MATH, see DISPLAYMATH
OTHER = 6			# CHAR WITH CATCODE OTHER, data = char
ACTIVE = 7			# ACTIVE CHAR
GOBBLEDWHITE = 8		# Gobbled LWSP, after CSNAME
ENDLINE = 9			# END-OF-LINE, data = '\n'
DENDLINE = 10			# DOUBLE EOL, data='\n', indicates \par
ENV = 11			# LaTeX-environment
					# data =(envname,[ch,ch,ch,.])
CSLINE = 12			# for texi: next chunk will be one group
					# of args. Will be set all on 1 line
IGNORE = 13			# IGNORE this data
ENDENV = 14			# TEMP END OF GROUP INDICATOR
IF = 15				# IF-directive
					# data = (flag,negate,[ch, ch, ch,...])
the_types = PLAIN, GROUP, CSNAME, COMMENT, DMATH, MATH, OTHER, ACTIVE, \
	  GOBBLEDWHITE, ENDLINE, DENDLINE, ENV, CSLINE, IGNORE, ENDENV, IF

# class, just to display symbolic name
class ChunkType:
	def init(self, chunk_type):
		if chunk_type not in the_types:
			raise 'ValueError', 'chunk_type not in the_types'
		self.chunk_type = chunk_type
		return self

	def __cmp__(self, other):
		if type(self) != type(other):
			other = chunk_type(other)
		return cmp(self.chunk_type, other.chunk_type)

	def __repr__(self):
		if self.chunk_type == PLAIN:
			return 'PLAIN'
		elif self.chunk_type == GROUP:
			return 'GROUP'
		elif self.chunk_type == CSNAME:
			return 'CSNAME'
		elif self.chunk_type == COMMENT:
			return 'COMMENT'
		elif self.chunk_type == DMATH:
			return 'DMATH'
		elif self.chunk_type == MATH:
			return 'MATH'
		elif self.chunk_type == OTHER:
			return 'OTHER'
		elif self.chunk_type == ACTIVE:
			return 'ACTIVE'
		elif self.chunk_type == GOBBLEDWHITE:
			return 'GOBBLEDWHITE'
		elif self.chunk_type == DENDLINE:
			return 'DENDLINE'
		elif self.chunk_type == ENDLINE:
			return 'ENDLINE'
		elif self.chunk_type == ENV:
			return 'ENV'
		elif self.chunk_type == CSLINE:
			return 'CSLINE'
		elif self.chunk_type == IGNORE:
			return 'IGNORE'
		elif self.chunk_type == ENDENV:
			return 'ENDENV'
		elif self.chunk_type == IF:
			return 'IF'
		else:
			raise ValueError, 'chunk_type not in the_types'

# ...and the wrapper
def chunk_type(type):
	return ChunkType().init(type)

# store a type object of the ChunkType-class-instance...
chunk_type_type = type(chunk_type(0))
	
# this class contains a part of the parsed buffer
class Chunk:
	def init(self, chtype, where, data):
		if type(chtype) != chunk_type_type:
			chtype = chunk_type(chtype)
		self.chtype = chtype
		if type(where) != type(0):
			raise TypeError, '\'where\' is not a number'
		self.where = where
		self.data = data
		##print 'CHUNK', self
		return self

	def __repr__(self):
		return 'chunk' + `self.chtype, self.where, self.data`

# and the wrapper
def chunk(chtype, where, data):
	 return Chunk().init(chtype, where, data)
	 


error = 'partparse.error'

#
# TeX's catcodes...
#
CC_ESCAPE = 0
CC_LBRACE = 1
CC_RBRACE = 2
CC_MATHSHIFT = 3
CC_ALIGNMENT = 4
CC_ENDLINE = 5
CC_PARAMETER = 6
CC_SUPERSCRIPT = 7
CC_SUBSCRIPT = 8
CC_IGNORE = 9
CC_WHITE = 10
CC_LETTER = 11
CC_OTHER = 12
CC_ACTIVE = 13
CC_COMMENT = 14
CC_INVALID = 15

# and the names
cc_names = [\
	  'CC_ESCAPE', \
	  'CC_LBRACE', \
	  'CC_RBRACE', \
	  'CC_MATHSHIFT', \
	  'CC_ALIGNMENT', \
	  'CC_ENDLINE', \
	  'CC_PARAMETER', \
	  'CC_SUPERSCRIPT', \
	  'CC_SUBSCRIPT', \
	  'CC_IGNORE', \
	  'CC_WHITE', \
	  'CC_LETTER', \
	  'CC_OTHER', \
	  'CC_ACTIVE', \
	  'CC_COMMENT', \
	  'CC_INVALID', \
	  ]

# Show a list of catcode-name-symbols
def pcl(codelist):
	result = ''
	for i in codelist:
		result = result + cc_names[i] + ', '
	return '[' + result[:-2] + ']'

# the name of the catcode (ACTIVE, OTHER, etc.)
def pc(code):
	return cc_names[code]
	

# Which catcodes make the parser stop parsing regular plaintext
regular_stopcodes = [CC_ESCAPE, CC_LBRACE, CC_RBRACE, CC_MATHSHIFT, \
	  CC_ALIGNMENT, CC_PARAMETER, CC_SUPERSCRIPT, CC_SUBSCRIPT, \
	  CC_IGNORE, CC_ACTIVE, CC_COMMENT, CC_INVALID, CC_ENDLINE]

# same for scanning a control sequence name
csname_scancodes = [CC_LETTER]

# same for gobbling LWSP
white_scancodes = [CC_WHITE]
##white_scancodes = [CC_WHITE, CC_ENDLINE]

# make a list of all catcode id's, except for catcode ``other''
all_but_other_codes = range(16)
del all_but_other_codes[CC_OTHER]
##print all_but_other_codes

# when does a comment end
comment_stopcodes = [CC_ENDLINE]

# gather all characters together, specified by a list of catcodes
def code2string(cc, codelist):
	##print 'code2string: codelist = ' + pcl(codelist),
	result = ''
	for category in codelist:
		if cc[category]:
			result = result + cc[category]
	##print 'result = ' + `result`
	return result

# automatically generate all characters of catcode other, being the
# complement set in the ASCII range (128 characters)
def make_other_codes(cc):
	otherchars = range(256)		# could be made 256, no problem
	for category in all_but_other_codes:
		if cc[category]:
			for c in cc[category]:
				otherchars[ord(c)] = None
	result = ''
	for i in otherchars:
		if i != None:
			result = result + chr(i)
	return result

# catcode dump (which characters have which catcodes).
def dump_cc(name, cc):
	##print '\t' + name
	##print '=' * (8+len(name))
	if len(cc) != 16:
		raise TypeError, 'cc not good cat class'
##	for i in range(16):
##		print pc(i) + '\t' + `cc[i]`
		

# In the beginning,....
epoch_cc = [None] * 16
##dump_cc('epoch_cc', epoch_cc)


# INITEX
initex_cc = epoch_cc[:]
initex_cc[CC_ESCAPE] = '\\'
initex_cc[CC_ENDLINE], initex_cc[CC_IGNORE], initex_cc[CC_WHITE] = \
	  '\n', '\0', ' '
initex_cc[CC_LETTER] = string.uppercase + string.lowercase
initex_cc[CC_COMMENT], initex_cc[CC_INVALID] = '%', '\x7F'
#initex_cc[CC_OTHER] = make_other_codes(initex_cc) I don't need them, anyway
##dump_cc('initex_cc', initex_cc)

	
# LPLAIN: LaTeX catcode setting (see lplain.tex)
lplain_cc = initex_cc[:]
lplain_cc[CC_LBRACE], lplain_cc[CC_RBRACE] = '{', '}'
lplain_cc[CC_MATHSHIFT] = '$'
lplain_cc[CC_ALIGNMENT] = '&'
lplain_cc[CC_PARAMETER] = '#'
lplain_cc[CC_SUPERSCRIPT] = '^\x0B'	# '^' and C-k
lplain_cc[CC_SUBSCRIPT] = '_\x01'	# '_' and C-a
lplain_cc[CC_WHITE] = lplain_cc[CC_WHITE] + '\t'
lplain_cc[CC_ACTIVE] = '~\x0C'		# '~' and C-l
lplain_cc[CC_OTHER] = make_other_codes(lplain_cc)
##dump_cc('lplain_cc', lplain_cc)

	
# Guido's LaTeX environment catcoded '_' as ``other''
# my own purpose catlist
my_cc = lplain_cc[:]
my_cc[CC_SUBSCRIPT] = my_cc[CC_SUBSCRIPT][1:] # remove '_' here
my_cc[CC_OTHER] = my_cc[CC_OTHER] + '_'	      # add it to OTHER list
dump_cc('my_cc', my_cc)



# needed for un_re, my equivalent for regexp-quote in Emacs
re_meaning = '\\[]^$'

def un_re(str):
	result = ''
	for i in str:
		if i in re_meaning:
			result = result + '\\'
		result = result + i
	return result
	
# NOTE the negate ('^') operator in *some* of the regexps below
def make_rc_regular(cc):
	# problems here if '[]' are included!!
	return regex.compile('[' + code2string(cc, regular_stopcodes) + ']')

def make_rc_cs_scan(cc):
	return regex.compile('[^' + code2string(cc, csname_scancodes) + ']')

def make_rc_comment(cc):
	return regex.compile('[' + code2string(cc, comment_stopcodes) + ']')

def make_rc_endwhite(cc):
	return regex.compile('[^' + code2string(cc, white_scancodes) + ']')
	


# regular: normal mode: 
rc_regular = make_rc_regular(my_cc)

# scan: scan a command sequence e.g. `newlength' or `mbox' or `;', `,' or `$'
rc_cs_scan = make_rc_cs_scan(my_cc)
rc_comment = make_rc_comment(my_cc)
rc_endwhite = make_rc_endwhite(my_cc)


# parseit (BUF, PARSEMODE=mode(MODE_REGULAR), START=0, RECURSION-LEVEL=0)
#     RECURSION-LEVEL will is incremented on entry.
#     result contains the list of chunks returned
#     together with this list, the buffer position is returned

#     RECURSION-LEVEL will be set to zero *again*, when recursively a
#     {,D}MATH-mode scan has been enetered.
#     This has been done in order to better check for environment-mismatches

def parseit(buf, *rest):
	global lineno

	if len(rest) == 3:
		parsemode, start, lvl = rest
	elif len(rest) == 2:
		parsemode, start, lvl = rest + (0, )
	elif len(rest) == 1:
		parsemode, start, lvl = rest + (0, 0)
	elif len(rest) == 0:
		parsemode, start, lvl = mode(MODE_REGULAR), 0, 0
	else:
		raise TypeError, 'usage: parseit(buf[, parsemode[, start[, level]]])'
	result = []
	end = len(buf)
	if lvl == 0 and parsemode == mode(MODE_REGULAR):
		lineno = 1
	lvl = lvl + 1

	##print 'parseit(' + epsilon(buf, start) + ', ' + `parsemode` + ', ' + `start` + ', ' + `lvl` + ')'

	#
	# some of the more regular modes...
	#

	if parsemode in (mode(MODE_REGULAR), mode(MODE_DMATH), mode(MODE_MATH)):
		cstate = []
		newpos = start
		curpmode = parsemode
		while 1:
			where = newpos
			#print '\tnew round: ' + epsilon(buf, where)
			if where == end:
				if lvl > 1 or curpmode != mode(MODE_REGULAR):
					# not the way we started...
					raise EOFError, 'premature end of file.' + lle(lvl, buf, where)
				# the real ending of lvl-1 parse
				return end, result

			pos = rc_regular.search(buf, where)

			if pos < 0:
				pos = end

			if pos != where:
				newpos, c = pos, chunk(PLAIN, where, (where, pos))
				result.append(c)
				continue


			#
			# ok, pos == where and pos != end
			#
			foundchar = buf[where]
			if foundchar in my_cc[CC_LBRACE]:
				# recursive subgroup parse...
				newpos, data = parseit(buf, curpmode, where+1, lvl)
				result.append(chunk(GROUP, where, data))
				
			elif foundchar in my_cc[CC_RBRACE]:
				if lvl <= 1:
					raise error, 'ENDGROUP while in base level.' + lle(lvl, buf, where)
				if  lvl == 1 and mode != mode(MODE_REGULAR):
					raise error, 'endgroup while in math mode. +lin() + epsilon(buf, where)'
				return where + 1, result
				
			elif foundchar in my_cc[CC_ESCAPE]:
				#
				# call the routine that actually deals with
				#     this problem. If do_ret is None, than
				#     return the value of do_ret
				#
				# Note that handle_cs might call this routine
				#     recursively again...
				#
				do_ret, newpos = handlecs(buf, where, \
					  curpmode, lvl, result, end)
				if do_ret != None:
					return do_ret
					
			elif foundchar in my_cc[CC_COMMENT]:
				newpos, data = parseit(buf, \
					  mode(MODE_COMMENT), where+1, lvl)
				result.append(chunk(COMMENT, where, data))
				
			elif foundchar in my_cc[CC_MATHSHIFT]:
				# note that recursive calls to math-mode
				# scanning are called with recursion-level 0
				# again, in order to check for bad mathend
				#
				if where + 1 != end and \
					  buf[where + 1] in \
					  my_cc[CC_MATHSHIFT]:
					#
					# double mathshift, e.g. '$$'
					#
					if curpmode == mode(MODE_REGULAR):
						newpos, data = parseit(buf, \
							  mode(MODE_DMATH), \
							  where+2, 0)
						result.append(chunk(DMATH, \
							  where, data))
					elif curpmode == mode(MODE_MATH):
						raise error, 'wrong math delimiiter' + lin() + epsilon(buf, where)
					elif lvl != 1:
						raise error, 'bad mathend.' + \
							  lle(lvl, buf, where)
					else:
						return where + 2, result
				else:
					#
					# single math shift, e.g. '$'
					#
					if curpmode == mode(MODE_REGULAR):
						newpos, data = parseit(buf, \
							  mode(MODE_MATH), \
							  where+1, 0)
						result.append(chunk(MATH, \
							  where, data))
					elif curpmode == mode(MODE_DMATH):
						raise error, 'wrong math delimiiter' + lin() + epsilon(buf, where)
					elif lvl != 1:
						raise error, 'bad mathend.' + \
							  lv(lvl, buf, where)
					else:
						return where + 1, result
					
			elif foundchar in my_cc[CC_IGNORE]:
				print 'warning: ignored char', `foundchar`
				newpos = where + 1
				
			elif foundchar in my_cc[CC_ACTIVE]:
				result.append(chunk(ACTIVE, where, foundchar))
				newpos = where + 1
				
			elif foundchar in my_cc[CC_INVALID]:
				raise error, 'invalid char ' + `foundchar`
				newpos = where + 1
				
			elif foundchar in my_cc[CC_ENDLINE]:
				#
				# after an end of line, eat the rest of
				# whitespace on the beginning of the next line
				# this is what LaTeX more or less does
				#
				# also, try to indicate double newlines (\par)
				#
				lineno = lineno + 1
				savedwhere = where
				newpos, dummy = parseit(buf, mode(MODE_GOBBLEWHITE), where + 1, lvl)
				if newpos != end and buf[newpos] in \
					  my_cc[CC_ENDLINE]:
					result.append(chunk(DENDLINE, \
						  savedwhere, foundchar))
				else:
					result.append(chunk(ENDLINE, \
						  savedwhere, foundchar))
			else:
				result.append(chunk(OTHER, where, foundchar))
				newpos = where + 1
				
	elif parsemode == mode(MODE_CS_SCAN):
		#
		# scan for a control sequence token. `\ape', `\nut' or `\%'
		#
		if start == end:
			raise EOFError, 'can\'t find end of csname'
		pos = rc_cs_scan.search(buf, start)
		if pos < 0:
			pos = end
		if pos == start:
			# first non-letter right where we started the search
			# ---> the control sequence name consists of one single
			# character. Also: don't eat white space...
			if buf[pos] in my_cc[CC_ENDLINE]:
				lineno = lineno + 1
			pos = pos + 1
			return pos, (start, pos)
		else:
			spos = pos
			if buf[pos] == '\n':
				lineno = lineno + 1
				spos = pos + 1
			pos2, dummy = parseit(buf, \
				  mode(MODE_GOBBLEWHITE), spos, lvl)
			return pos2, (start, pos)

	elif parsemode == mode(MODE_GOBBLEWHITE):
		if start == end:
			return start, ''
		pos = rc_endwhite.search(buf, start)
		if pos < 0:
			pos = start
		return pos, (start, pos)

	elif parsemode == mode(MODE_COMMENT):
		pos = rc_comment.search(buf, start)
		lineno = lineno + 1
		if pos < 0:
			print 'no newline perhaps?'
			raise EOFError, 'can\'t find end of comment'
		pos = pos + 1
		pos2, dummy = parseit(buf, mode(MODE_GOBBLEWHITE), pos, lvl)
		return pos2, (start, pos)


	else:
		raise error, 'Unknown mode (' + `parsemode` + ')'


#moreresult = cswitch(buf[x1:x2], buf, newpos, parsemode, lvl)

#boxcommands = 'mbox', 'fbox'
#defcommands = 'def', 'newcommand'

endverbstr = '\\end{verbatim}'

re_endverb = regex.compile(un_re(endverbstr))

#
# handlecs: helper function for parseit, for the special thing we might
#     wanna do after certain command control sequences
# returns: None or return_data, newpos
#
# in the latter case, the calling function is instructed to immediately
# return with the data in return_data
#
def handlecs(buf, where, curpmode, lvl, result, end):
	global lineno

	# get the control sequence name...
	newpos, data = parseit(buf, mode(MODE_CS_SCAN), where+1, lvl)
	saveddata = data
	
	if s(buf, data) in ('begin', 'end'):
		# skip the expected '{' and get the LaTeX-envname '}'
		newpos, data = parseit(buf, mode(MODE_REGULAR), newpos+1, lvl)
		if len(data) != 1:
			raise error, 'expected 1 chunk of data.' + \
				  lle(lvl, buf, where)

		# yucky, we've got an environment
		envname = s(buf, data[0].data)
		##print 'FOUND ' + s(buf, saveddata) + '. Name ' + `envname` + '.' + lv(lvl)
		if s(buf, saveddata) == 'begin' and envname == 'verbatim':
			# verbatim deserves special treatment
			pos = re_endverb.search(buf, newpos)
			if pos < 0:
				raise error, `endverbstr` + ' not found.' + lle(lvl, buf, where)
			result.append(chunk(ENV, where, (envname, [chunk(PLAIN, newpos, (newpos, pos))])))
			newpos = pos + len(endverbstr)
			
		elif s(buf, saveddata) == 'begin':
			# start parsing recursively... If that parse returns
			# from an '\end{...}', then should the last item of
			# the returned data be a string containing the ended
			# environment
			newpos, data = parseit(buf, curpmode, newpos, lvl)
			if not data or type(data[-1]) != type(''):
				raise error, 'missing \'end\'' + lle(lvl, buf, where) + epsilon(buf, newpos)
			retenv = data[-1]
			del data[-1]
			if retenv != envname:
				#[`retenv`, `envname`]
				raise error, 'environments do not match.' + \
					  lle(lvl, buf, where) + \
					  epsilon(buf, newpos)
			result.append(chunk(ENV, where, (retenv, data)))
		else:
			# 'end'... append the environment name, as just
			# pointed out, and order parsit to return...
			result.append(envname)
			##print 'POINT of return: ' + epsilon(buf, newpos)
			# the tuple will be returned by parseit
			return (newpos, result), newpos

	# end of \begin ... \end handling
			
	elif s(buf, data)[0:2] == 'if':
		# another scary monster: the 'if' directive
		flag = s(buf, data)[2:]

		# recursively call parseit, just like environment above..
		# the last item of data should contain the if-termination
		# e.g., 'else' of 'fi'
		newpos, data = parseit(buf, curpmode, newpos, lvl)
		if not data or data[-1] not in ('else', 'fi'):
			raise error, 'wrong if... termination' + \
				  lle(lvl, buf, where) + epsilon(buf, newpos)

		ifterm = data[-1]
		del data[-1]
		# 0 means dont_negate flag
		result.append(chunk(IF, where, (flag, 0, data)))
		if ifterm == 'else':
			# do the whole thing again, there is only one way
			# to end this one, by 'fi'
			newpos, data = parseit(buf, curpmode, newpos, lvl)
			if not data or data[-1] not in ('fi', ):
				raise error, 'wrong if...else... termination' \
					  + lle(lvl, buf, where) \
					  + epsilon(buf, newpos)

			ifterm = data[-1]
			del data[-1]
			result.append(chunk(IF, where, (flag, 1, data)))
		#done implicitely: return None, newpos

	elif s(buf, data) in ('else', 'fi'):
		result.append(s(buf, data))
		# order calling party to return tuple
		return (newpos, result), newpos

	# end of \if, \else, ... \fi handling

	elif s(buf, saveddata) == 'verb':
		x2 = saveddata[1]
		result.append(chunk(CSNAME, where, data))
		if x2 == end:
			raise error, 'premature end of command.' + lle(lvl, buf, where)
		delimchar = buf[x2]
		##print 'VERB: delimchar ' + `delimchar`
		pos = regex.compile(un_re(delimchar)).search(buf, x2 + 1)
		if pos < 0:
			raise error, 'end of \'verb\' argument (' + \
				  `delimchar` + ') not found.' + \
				  lle(lvl, buf, where)
		result.append(chunk(GROUP, x2, [chunk(PLAIN, x2+1, (x2+1, pos))]))
		newpos = pos + 1
	else:
		result.append(chunk(CSNAME, where, data))
	return None, newpos

# this is just a function to get the string value if the possible data-tuple
def s(buf, data):
	if type(data) == type(''):
		return data
	if len(data) != 2 or not (type(data[0]) == type(data[1]) == type(0)):
		raise TypeError, 'expected tuple of 2 integers'
	x1, x2 = data
	return buf[x1:x2]
	

##length, data1, i = getnextarg(length, buf, pp, i + 1)

# make a deep-copy of some chunks
def crcopy(r):
	result = []
	for x in r:
		result.append(chunkcopy(x))
	return result
	
		

# copy a chunk, would better be a method of class Chunk...
def chunkcopy(ch):
	if ch.chtype == chunk_type(GROUP):
		listc = ch.data[:]
		for i in range(len(listc)):
			listc[i] = chunkcopy(listc[i])
		return chunk(GROUP, ch.where, listc)
	else:
		return chunk(ch.chtype, ch.where, ch.data)


# get next argument for TeX-macro, flatten a group (insert between)
# or return Command Sequence token, or give back one character
def getnextarg(length, buf, pp, item):

	##wobj = Wobj().init()
	##dumpit(buf, wobj.write, pp[item:min(length, item + 5)])
	##print 'GETNEXTARG, (len, item) =', `length, item` + ' ---> ' + wobj.data + ' <---'

	while item < length and pp[item].chtype == chunk_type(ENDLINE):
		del pp[item]
		length = length - 1
	if item >= length:
		raise error, 'no next arg.' + epsilon(buf, pp[-1].where)
	if pp[item].chtype == chunk_type(GROUP):
		newpp = pp[item].data
		del pp[item]
		length = length - 1
		changeit(buf, newpp)
		length = length + len(newpp)
		pp[item:item] = newpp
		item = item + len(newpp)
		if len(newpp) < 10:
			wobj = Wobj().init()
			dumpit(buf, wobj.write, newpp)
			##print 'GETNEXTARG: inserted ' + `wobj.data`
		return length, item
	elif pp[item].chtype == chunk_type(PLAIN):
		#grab one char
		print 'WARNING: grabbing one char'
		if len(s(buf, pp[item].data)) > 1:
			pp.insert(item, chunk(PLAIN, pp[item].where, s(buf, pp[item].data)[:1]))
			item, length = item+1, length+1
			pp[item].data = s(buf, pp[item].data)[1:]
		else:
			item = item+1
		return length, item
	else:
		try:
			str = `s(buf, ch.data)`
		except TypeError:
			str = `ch.data`
			if len(str) > 400:
				str = str[:400] + '...'
		print 'GETNEXTARG:', ch.chtype, 'not handled, data ' + str
		return length, item


# this one is needed to find the end of LaTeX's optional argument, like
# item[...]
re_endopt = regex.compile(']')

# get a LaTeX-optional argument, you know, the square braces '[' and ']'
def getoptarg(length, buf, pp, item):

	wobj = Wobj().init()
	dumpit(buf, wobj.write, pp[item:min(length, item + 5)])
	##print 'GETOPTARG, (len, item) =', `length, item` + ' ---> ' + wobj.data + ' <---'

	if item >= length or \
		  pp[item].chtype != chunk_type(PLAIN) or \
		  s(buf, pp[item].data)[0] != '[':
		return length, item

	pp[item].data = s(buf, pp[item].data)[1:]
	if len(pp[item].data) == 0:
		del pp[item]
		length = length-1

	while 1:
		if item == length:
			raise error, 'No end of optional arg found'
		if pp[item].chtype == chunk_type(PLAIN):
			text = s(buf, pp[item].data)
			pos = re_endopt.search(text)
			if pos >= 0:
				pp[item].data = text[:pos]
				if pos == 0:
					del pp[item]
					length = length-1
				else:
					item=item+1
				text = text[pos+1:]
				
				while text and text[0] in ' \t':
					text = text[1:]
					
				if text:
					pp.insert(item, chunk(PLAIN, 0, text))
					length = length + 1
				return length, item

		item = item+1


# Wobj just add write-requests to the ``data'' attribute
class Wobj:
	def init(self):
		self.data = ''
		return self
	def write(self, data):
		self.data = self.data + data
		
# ignore these commands
ignoredcommands = ('bcode', 'ecode', 'optional')
# map commands like these to themselves as plaintext
wordsselves = ('UNIX', 'ABC', 'C', 'ASCII', 'EOF')
# \{ --> {,  \} --> }, etc
themselves = ('{', '}', '.', '@') + wordsselves
# these ones also themselves (see argargs macro in myformat.sty)
inargsselves = (',', '[', ']', '(', ')')
# this is how *I* would show the difference between emph and strong
#  code 1 means: fold to uppercase
markcmds = {'code': ('', ''), 'var': 1, 'emph': ('_', '_'), \
	  'strong': ('*', '*')}

# recognise patter {\FONTCHANGE-CMD TEXT} to \MAPPED-FC-CMD{TEXT}
fontchanges = {'rm': 'r', 'it': 'i', 'em': 'emph', 'bf': 'b', 'tt': 't'}

# transparent for these commands
for_texi = ('emph', 'var', 'strong', 'code', 'kbd', 'key', 'dfn', 'samp', \
	  'r', 'i', 't')


# try to remove macros and return flat text
def flattext(buf, pp):
	pp = crcopy(pp)
	##print '---> FLATTEXT ' + `pp`
	wobj = Wobj().init()

	i, length = 0, len(pp)
	while 1:
		if len(pp) != length:
			raise 'FATAL', 'inconsistent length'
		if i >= length:
			break
		ch = pp[i]
		i = i+1
		if ch.chtype == chunk_type(PLAIN):
			pass
		elif ch.chtype == chunk_type(CSNAME):
			if s(buf, ch.data) in themselves or hist.inargs and s(buf, ch.data) in inargsselves:
				ch.chtype = chunk_type(PLAIN)
			elif s(buf, ch.data) == 'e':
				ch.chtype = chunk_type(PLAIN)
				ch.data = '\\'
			elif len(s(buf, ch.data)) == 1 \
				  and s(buf, ch.data) in onlylatexspecial:
				ch.chtype = chunk_type(PLAIN)
				# if it is followed by an empty group,
				# remove that group, it was needed for
				# a true space
				if i < length \
					  and pp[i].chtype==chunk_type(GROUP) \
					  and len(pp[i].data) == 0:
					del pp[i]
					length = length-1
						
			elif s(buf, ch.data) in markcmds.keys():
				length, newi = getnextarg(length, buf, pp, i)
				str = flattext(buf, pp[i:newi])
				del pp[i:newi]
				length = length - (newi - i)
				ch.chtype = chunk_type(PLAIN)
				markcmd = s(buf, ch.data)
				x = markcmds[markcmd]
				if type(x) == type(()):
					pre, after = x
					str = pre+str+after
				elif x == 1:
					str = string.upper(str)
				else:
					raise 'FATAL', 'corrupt markcmds'
				ch.data = str
			else:
				if s(buf, ch.data) not in ignoredcommands:
					print 'WARNING: deleting command ' + `s(buf, ch.data)`
					print 'PP' + `pp[i-1]`
				del pp[i-1]
				i, length = i-1, length-1
		elif ch.chtype == chunk_type(GROUP):
			length, newi = getnextarg(length, buf, pp, i-1)
			i = i-1
##			str = flattext(buf, crcopy(pp[i-1:newi]))
##			del pp[i:newi]
##			length = length - (newi - i)
##			ch.chtype = chunk_type(PLAIN)
##			ch.data = str
		else:
			pass
		
	dumpit(buf, wobj.write, pp)
	##print 'FLATTEXT: RETURNING ' + `wobj.data`
	return wobj.data

# try to generate node names (a bit shorter than the chapter title)
# note that the \nodename command (see elsewhere) overules these efforts
def invent_node_names(text):
	words = string.split(text)

	##print 'WORDS ' + `words`

	if len(words) == 2 \
		  and string.lower(words[0]) == 'built-in' \
		  and string.lower(words[1]) not in ('modules', 'functions'):
		return words[1]
	if len(words) == 3 and string.lower(words[1]) == 'module':
		return words[2]
	if len(words) == 3 and string.lower(words[1]) == 'object':
		return string.join(words[0:2])
	if len(words) > 4 and string.lower(string.join(words[-4:])) == \
		  'methods and data attributes':
		return string.join(words[:2])
	return text
	
re_commas_etc = regex.compile('[,`\'@{}]')

re_whitespace = regex.compile('[ \t]*')


##nodenamecmd = next_command_p(length, buf, pp, newi, 'nodename')

# look if the next non-white stuff is also a command, resulting in skipping
# double endlines (DENDLINE) too, and thus omitting \par's
# Sometimes this is too much, maybe consider DENDLINE's as stop
def next_command_p(length, buf, pp, i, cmdname):

	while 1:
		if i >= len(pp):
			break
		ch = pp[i]
		i = i+1
		if ch.chtype == chunk_type(ENDLINE):
			continue
		if ch.chtype == chunk_type(DENDLINE):
			continue
		if ch.chtype == chunk_type(PLAIN):
			if re_whitespace.search(s(buf, ch.data)) == 0 and \
				  re_whitespace.match(s(buf, ch.data)) == len(s(buf, ch.data)):
				continue
			return -1
		if ch.chtype == chunk_type(CSNAME):
			if s(buf, ch.data) == cmdname:
				return i # _after_ the command
			return -1
		return -1
			
				
# things that are special to LaTeX, but not to texi..
onlylatexspecial = '_~^$#&%'

class Struct: pass

hist = Struct()
out = Struct()

def startchange():
	global hist, out

	hist.inenv = []
	hist.nodenames = []
	hist.cindex = []
	hist.inargs = 0
	hist.enumeratenesting, hist.itemizenesting = 0, 0

	out.doublenodes = []
	out.doublecindeces = []
	

spacech = [chunk(PLAIN, 0, ' ')]
commach = [chunk(PLAIN, 0, ', ')]
cindexch = [chunk(CSLINE, 0, 'cindex')]

# the standard variation in symbols for itemize
itemizesymbols = ['bullet', 'minus', 'dots']

# same for enumerate
enumeratesymbols = ['1', 'A', 'a']

##
## \begin{ {func,data,exc}desc }{name}...
##   the resulting texi-code is dependent on the contents of indexsubitem
##

# indexsubitem: `['XXX', 'function']
# funcdesc:
#     deffn {`idxsi`} NAME (FUNCARGS)

# indexsubitem: `['XXX', 'method']`
# funcdesc:
#     defmethod {`idxsi[0]`} NAME (FUNCARGS)

# indexsubitem: `['in', 'module', 'MODNAME']'
# datadesc:
#     defcv data {`idxsi[1:]`} NAME
# excdesc:
#     defcv exception {`idxsi[1:]`} NAME
# funcdesc:
#     deffn {function of `idxsi[1:]`} NAME (FUNCARGS)

# indexsubitem: `['OBJECT', 'attribute']'
# datadesc
#     defcv attribute {`OBJECT`} NAME


## this routine will be called on \begin{funcdesc}{NAME}{ARGS}
##   or \funcline{NAME}{ARGS}
##
def do_funcdesc(length, buf, pp, i):
	startpoint = i-1
	ch = pp[startpoint]
	wh = ch.where
	length, newi = getnextarg(length, buf, pp, i)
	funcname = chunk(GROUP, wh, pp[i:newi])
	del pp[i:newi]
	length = length - (newi-i)
	save = hist.inargs
	hist.inargs = 1
	length, newi = getnextarg(length, buf, pp, i)
	hist.inargs = save
	del save
	the_args = [chunk(PLAIN, wh, '()'[0])] + \
		  pp[i:newi] + \
		  [chunk(PLAIN, wh, '()'[1])]
	del pp[i:newi]
	length = length - (newi-i)

	idxsi = hist.indexsubitem	# words
	command = ''
	cat_class = ''
	if idxsi and idxsi[-1] == 'method':
		command = 'defmethod'
		cat_class = string.join(idxsi[:-1])
	elif len(idxsi) == 2 and idxsi[1] == 'function':
		command = 'deffn'
		cat_class = string.join(idxsi)
	elif len(idxsi) == 3 and idxsi[:2] == ['in', 'module']:
		command = 'deffn'
		cat_class = 'function of ' + string.join(idxsi[1:])

	if not command:
		raise error, 'don\'t know what to do with indexsubitem ' + `idxsi`
		
	ch.chtype = chunk_type(CSLINE)
	ch.data = command
	
	cslinearg = [chunk(GROUP, wh, [chunk(PLAIN, wh, cat_class)])]
	cslinearg.append(chunk(PLAIN, wh, ' '))
	cslinearg.append(funcname)
	cslinearg.append(chunk(PLAIN, wh, ' '))
	l = len(cslinearg)
	cslinearg[l:l] = the_args

	pp.insert(i, chunk(GROUP, wh, cslinearg))
	i, length = i+1, length+1
	hist.command = command
	return length, i
	

## this routine will be called on \begin{excdesc}{NAME}
## or \excline{NAME}
##	
def do_excdesc(length, buf, pp, i):
	startpoint = i-1
	ch = pp[startpoint]
	wh = ch.where
	length, newi = getnextarg(length, buf, pp, i)
	excname = chunk(GROUP, wh, pp[i:newi])
	del pp[i:newi]
	length = length - (newi-i)

	idxsi = hist.indexsubitem	# words
	command = ''
	cat_class = ''
	class_class = ''
	if len(idxsi) == 2 and idxsi[1] == 'exception':
		command = 'defvr'
		cat_class = string.join(idxsi)
	elif len(idxsi) == 3 and idxsi[:2] == ['in', 'module']:
		command = 'defcv'
		cat_class = 'exception'
		class_class = string.join(idxsi[1:])
	elif len(idxsi) == 4 and idxsi[:3] == ['exception', 'in', 'module']:
		command = 'defcv'
		cat_class = 'exception'
		class_class = string.join(idxsi[2:])
		

	if not command:
		raise error, 'don\'t know what to do with indexsubitem ' + `idxsi`
		
	ch.chtype = chunk_type(CSLINE)
	ch.data = command
	
	cslinearg = [chunk(GROUP, wh, [chunk(PLAIN, wh, cat_class)])]
	cslinearg.append(chunk(PLAIN, wh, ' '))
	if class_class:
		cslinearg.append(chunk(GROUP, wh, [chunk(PLAIN, wh, class_class)]))
		cslinearg.append(chunk(PLAIN, wh, ' '))
	cslinearg.append(excname)

	pp.insert(i, chunk(GROUP, wh, cslinearg))
	i, length = i+1, length+1
	hist.command = command
	return length, i

## same for datadesc or dataline...
def do_datadesc(length, buf, pp, i):
	startpoint = i-1
	ch = pp[startpoint]
	wh = ch.where
	length, newi = getnextarg(length, buf, pp, i)
	dataname = chunk(GROUP, wh, pp[i:newi])
	del pp[i:newi]
	length = length - (newi-i)

	idxsi = hist.indexsubitem	# words
	command = ''
	cat_class = ''
	class_class = ''
	if len(idxsi) == 2 and idxsi[1] == 'attribute':
		command = 'defcv'
		cat_class = 'attribute'
		class_class = idxsi[0]
	elif len(idxsi) == 3 and idxsi[:2] == ['in', 'module']:
		command = 'defcv'
		cat_class = 'data'
		class_class = string.join(idxsi[1:])
	elif len(idxsi) == 4 and idxsi[:3] == ['data', 'in', 'module']:
		command = 'defcv'
		cat_class = 'data'
		class_class = string.join(idxsi[2:])
		

	if not command:
		raise error, 'don\'t know what to do with indexsubitem ' + `idxsi`
		
	ch.chtype = chunk_type(CSLINE)
	ch.data = command
	
	cslinearg = [chunk(GROUP, wh, [chunk(PLAIN, wh, cat_class)])]
	cslinearg.append(chunk(PLAIN, wh, ' '))
	if class_class:
		cslinearg.append(chunk(GROUP, wh, [chunk(PLAIN, wh, class_class)]))
		cslinearg.append(chunk(PLAIN, wh, ' '))
	cslinearg.append(dataname)

	pp.insert(i, chunk(GROUP, wh, cslinearg))
	i, length = i+1, length+1
	hist.command = command
	return length, i
	

# regular indices: those that are not set in tt font by default....
regindices = ('cindex', )

# remove illegal characters from node names
def rm_commas_etc(text):
	result = ''
	changed = 0
	while 1:
		pos = re_commas_etc.search(text)
		if pos >= 0:
			changed = 1
			result = result + text[:pos]
			text = text[pos+1:]
		else:
			result = result + text
			break
	if changed:
		print 'Warning: nodename changhed to ' + `result`

	return result
			
# boolean flags
flags = {'texi': 1}
	

##
## changeit: the actual routine, that changes the contents of the parsed
##           chunks
##

def changeit(buf, pp):
	global onlylatexspecial, hist, out

	i, length = 0, len(pp)
	while 1:
		# sanity check: length should always equal len(pp)
		if len(pp) != length:
			raise 'FATAL', 'inconsistent length. thought ' + `length` + ', but should really be ' + `len(pp)`
		if i >= length:
			break
		ch = pp[i]
		i = i + 1

		if type(ch) == type(''):
			#normally, only chunks are present in pp,
			# but in some cases, some extra info
			# has been inserted, e.g., the \end{...} clauses
			raise 'FATAL', 'got string, probably too many ' + `end`

		if ch.chtype == chunk_type(GROUP):
			# check for {\em ...} constructs
			if ch.data and \
				  ch.data[0].chtype == chunk_type(CSNAME) and \
				  s(buf, ch.data[0].data) in fontchanges.keys():
				k = s(buf, ch.data[0].data)
				del ch.data[0]
				pp.insert(i-1, chunk(CSNAME, ch.where, fontchanges[k]))
				length, i = length+1, i+1

			# recursively parse the contents of the group
			changeit(buf, ch.data)

		elif ch.chtype == chunk_type(IF):
			# \if...
			flag, negate, data = ch.data
			##print 'IF: flag, negate = ' + `flag, negate`
			if flag not in flags.keys():
				raise error, 'unknown flag ' + `flag`
				
			value = flags[flag]
			if negate:
				value = (not value)
			del pp[i-1]
			length, i = length-1, i-1
			if value:
				pp[i:i] = data
				length = length + len(data)
					
			
		elif ch.chtype == chunk_type(ENV):
			# \begin{...} ....
			envname, data = ch.data

			#push this environment name on stack
			hist.inenv.insert(0, envname)

			#append an endenv chunk after grouped data
			data.append(chunk(ENDENV, ch.where, envname))
			##[`data`]

			#delete this object
			del pp[i-1]
			i, length = i-1, length-1

			#insert found data
			pp[i:i] = data
			length = length + len(data)

			if envname == 'verbatim':
				pp[i:i] = [chunk(CSLINE, ch.where, 'example'), \
					  chunk(GROUP, ch.where, [])]
				length, i = length+2, i+2

			elif envname == 'itemize':
				if hist.itemizenesting > len(itemizesymbols):
					raise error, 'too deep itemize nesting'
				ingroupch = [chunk(CSNAME, ch.where,\
					  itemizesymbols[hist.itemizenesting])]
				hist.itemizenesting = hist.itemizenesting + 1
				pp[i:i] = [chunk(CSLINE, ch.where, 'itemize'),\
					  chunk(GROUP, ch.where, ingroupch)]
				length, i = length+2, i+2
				
			elif envname == 'enumerate':
				if hist.enumeratenesting > len(enumeratesymbols):
					raise error, 'too deep enumerate nesting'
				ingroupch = [chunk(PLAIN, ch.where,\
					  enumeratesymbols[hist.enumeratenesting])]
				hist.enumeratenesting = hist.enumeratenesting + 1
				pp[i:i] = [chunk(CSLINE, ch.where, 'enumerate'),\
					  chunk(GROUP, ch.where, ingroupch)]
				length, i = length+2, i+2
				
			elif envname == 'description':
				ingroupch = [chunk(CSNAME, ch.where, 'b')]
				pp[i:i] = [chunk(CSLINE, ch.where, 'table'), \
					  chunk(GROUP, ch.where, ingroupch)]
				length, i = length+2, i+2
				
			elif envname == 'tableiii':
				wh = ch.where
				newcode = []
				
				#delete tabular format description
				# e.g., {|l|c|l|}
				length, newi = getnextarg(length, buf, pp, i)
				del pp[i:newi]
				length = length - (newi-i)

				newcode.append(chunk(CSLINE, wh, 'table'))
				ingroupch = [chunk(CSNAME, wh, 'asis')]
				newcode.append(chunk(GROUP, wh, ingroupch))
				newcode.append(chunk(CSLINE, wh, 'item'))

				#get the name of macro for @item
				# e.g., {code}
				length, newi = getnextarg(length, buf, pp, i)
				
				if newi-i != 1:
					raise error, 'Sorry, expected 1 chunk argument'
				if pp[i].chtype != chunk_type(PLAIN):
					raise error, 'Sorry, expected plain text argument'
				hist.itemargmacro = s(buf, pp[i].data)
				del pp[i:newi]
				length = length - (newi-i)

				for count in range(3):
					length, newi = getnextarg(length, buf, pp, i)
					emphgroup = [\
						  chunk(CSNAME, wh, 'emph'), \
						  chunk(GROUP, 0, pp[i:newi])]
					del pp[i:newi]
					length = length - (newi-i)
					if count == 0:
						itemarg = emphgroup
					elif count == 2:
						itembody = itembody + \
							  [chunk(PLAIN, wh, '  ---  ')] + \
							  emphgroup
					else:
						itembody = emphgroup
				newcode.append(chunk(GROUP, wh, itemarg))
				newcode = newcode + itembody + [chunk(DENDLINE, wh, '\n')]
				pp[i:i] = newcode
				l = len(newcode)
				length, i = length+l, i+l
				del newcode, l

				if length != len(pp):
					raise 'STILL, SOMETHING wrong', `i`


			elif envname == 'funcdesc':
				pp.insert(i, chunk(PLAIN, ch.where, ''))
				i, length = i+1, length+1
				length, i = do_funcdesc(length, buf, pp, i)
					  
			elif envname == 'excdesc':
				pp.insert(i, chunk(PLAIN, ch.where, ''))
				i, length = i+1, length+1
				length, i = do_excdesc(length, buf, pp, i)
					  
			elif envname == 'datadesc':
				pp.insert(i, chunk(PLAIN, ch.where, ''))
				i, length = i+1, length+1
				length, i = do_datadesc(length, buf, pp, i)
					  
			else:
				print 'WARNING: don\'t know what to do with env ' + `envname`
				
		elif ch.chtype == chunk_type(ENDENV):
			envname = ch.data
			if envname != hist.inenv[0]:
				raise error, '\'end\' does not match. Name ' + `envname` + ', expected ' + `hist.inenv[0]`
			del hist.inenv[0]
			del pp[i-1]
			i, length = i-1, length-1

			if envname == 'verbatim':
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, 'example')])]
				i, length = i+2, length+2
			elif envname == 'itemize':
				hist.itemizenesting = hist.itemizenesting - 1
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, 'itemize')])]
				i, length = i+2, length+2
			elif envname == 'enumerate':
				hist.enumeratenesting = hist.enumeratenesting-1
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, 'enumerate')])]
				i, length = i+2, length+2
			elif envname == 'description':
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, 'table')])]
				i, length = i+2, length+2
			elif envname == 'tableiii':
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, 'table')])]
				i, length = i+2, length + 2
				pp.insert(i, chunk(DENDLINE, ch.where, '\n'))
				i, length = i+1, length+1

			elif envname in ('funcdesc', 'excdesc', 'datadesc'):
				pp[i:i] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, hist.command)])]
				i, length = i+2, length+2
			else:
				print 'WARNING: ending env ' + `envname` + 'has no actions'
				
		elif ch.chtype == chunk_type(CSNAME):
			# control name transformations
			if s(buf, ch.data) in ignoredcommands:
				del pp[i-1]
				i, length = i-1, length-1
			elif s(buf, ch.data) == '@' and \
				  i != length and \
				  pp[i].chtype == chunk_type(PLAIN) and \
				  s(buf, pp[i].data)[0] == '.':
				# \@. --> \. --> @.
				ch.data = '.'
				del pp[i]
				length = length-1
			elif s(buf, ch.data) == '\\':
				# \\ --> \* --> @*
				ch.data = '*'
			elif len(s(buf, ch.data)) == 1 and \
				  s(buf, ch.data) in onlylatexspecial:
				ch.chtype = chunk_type(PLAIN)
				# check if such a command is followed by
				# an empty group: e.g., `\%{}'.  If so, remove
				# this empty group too
				if i < length and \
					  pp[i].chtype == chunk_type(GROUP) \
					  and len(pp[i].data) == 0:
					del pp[i]
					length = length-1

			elif hist.inargs and s(buf, ch.data) in inargsselves:
				# This is the special processing of the
				# arguments of the \begin{funcdesc}... or
				# \funcline... arguments
				# \, --> , \[ --> [, \] --> ]
				ch.chtype = chunk_type(PLAIN)
				
			elif s(buf, ch.data) == 'renewcommand':
				# \renewcommand{\indexsubitem}....
				i, length = i-1, length-1
				del pp[i]
				length, newi = getnextarg(length, buf, pp, i)
				if newi-i == 1 \
					  and i < length \
					  and pp[i].chtype == chunk_type(CSNAME) \
					  and s(buf, pp[i].data) == 'indexsubitem':
					del pp[i:newi]
					length = length - (newi-i)
					length, newi = getnextarg(length, buf, pp, i)
					text = flattext(buf, pp[i:newi])
					if text[0] != '(' or text[-1] != ')':
						raise error, 'expected indexsubitme enclosed in braces'
					words = string.split(text[1:-1])
					hist.indexsubitem = words
					del text, words
				else:
					print 'WARNING: renewcommand with unsupported arg removed'
				del pp[i:newi]
				length = length - (newi-i)

			elif s(buf, ch.data) == 'item':
				ch.chtype = chunk_type(CSLINE)
				length, newi = getoptarg(length, buf, pp, i)
				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)
				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				i, length = i+1, length+1
				
			elif s(buf, ch.data) == 'ttindex':
				idxsi = hist.indexsubitem

				cat_class = ''
				if len(idxsi) >= 2 and idxsi[1] in \
					  ('method', 'function'):
					command = 'findex'
				elif len(idxsi) >= 2 and idxsi[1] in \
					  ('exception', 'object'):
					command = 'vindex'
				else:
					print 'WARNING: can\'t categorize ' + `idxsi` + ' for \'ttindex\' command'
					command = 'cindex'

				if not cat_class:
					cat_class = '('+string.join(idxsi)+')'

				ch.chtype = chunk_type(CSLINE)
				ch.data = command

				length, newi = getnextarg(length, buf, pp, i)
				arg = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)

				cat_arg = [chunk(PLAIN, ch.where, cat_class)]

				# determine what should be set in roman, and
				# what in tt-font
				if command in regindices:

					arg = [chunk(CSNAME, ch.where, 't'), \
						  chunk(GROUP, ch.where, arg)]
				else:
					cat_arg = [chunk(CSNAME, ch.where, 'r'), \
						  chunk(GROUP, ch.where, cat_arg)]

				ingroupch = arg + \
					  [chunk(PLAIN, ch.where, ' ')] + \
					  cat_arg
				
				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1

				
			elif s(buf, ch.data) == 'ldots':
				# \ldots --> \dots{} --> @dots{}
				ch.data = 'dots'
				if i == length \
					  or pp[i].chtype != chunk_type(GROUP) \
					  or pp[i].data != []:
					pp.insert(i, chunk(GROUP, ch.where, []))
					i, length = i+1, length+1
			elif s(buf, ch.data) in wordsselves:
				# \UNIX --> UNIX
				ch.chtype = chunk_type(PLAIN)
				if i != length \
					  and pp[i].chtype == chunk_type(GROUP) \
					  and pp[i].data == []:
					del pp[i]
					length = length-1
			elif s(buf, ch.data) in for_texi:
				pass

			elif s(buf, ch.data) == 'e':
				# \e --> \
				ch.data = '\\'
				ch.chtype = chunk_type(PLAIN)
			elif s(buf, ch.data) == 'lineiii':
				# This is the most tricky one
				# \lineiii{a1}{a2}[{a3}] -->
				# @item @<cts. of itemargmacro>{a1}
				#  a2 [ -- a3]
				#
				##print 'LINEIIIIII!!!!!!!'
##				wobj = Wobj().init()
##				dumpit(buf, wobj.write, pp[i-1:i+5])
##				print '--->' + wobj.data + '<----'
				if not hist.inenv:
					raise error, \
						  'no environment for lineiii'
				if hist.inenv[0] != 'tableiii':
					raise error, \
						  'wrong command (' + \
						  `'lineiii'` + \
						  ') in wrong environment (' \
						  + `hist.inenv[0]` + ')'
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'item'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = [chunk(CSNAME, 0, \
					  hist.itemargmacro), \
					  chunk(GROUP, 0, pp[i:newi])]
				del pp[i:newi]
				length = length - (newi-i)
##				print 'ITEM ARG: --->',
##				wobj = Wobj().init()
##				dumpit(buf, wobj.write, ingroupch)
##				print wobj.data, '<---'
				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				grouppos = i
				i, length = i+1, length+1
				length, i = getnextarg(length, buf, pp, i)
				length, newi = getnextarg(length, buf, pp, i)
				if newi > i:
					# we have a 3rd arg
					pp.insert(i, chunk(PLAIN, ch.where, '  ---  '))
					i = newi + 1
					length = length + 1
##					pp[grouppos].data = pp[grouppos].data \
##						  + [chunk(PLAIN, ch.where, '  ')] \
##						  + pp[i:newi]
##					del pp[i:newi]
##					length = length - (newi-i)
				if length != len(pp):
					raise 'IN LINEIII IS THE ERR', `i`

			elif s(buf, ch.data) in ('chapter', 'section', 'subsection', 'subsubsection'):
				#\xxxsection{A} ---->
				# @node A, , ,
				# @xxxsection A
				## also: remove commas and quotes
				ch.chtype = chunk_type(CSLINE)
				length, newi = getnextarg(length, buf, pp, i)
				afternodenamecmd = next_command_p(length, buf, pp, newi, 'nodename')
				if afternodenamecmd < 0:
					cp1 = crcopy(pp[i:newi])
					pp[i:newi] = [\
						  chunk(GROUP, ch.where, \
						  pp[i:newi])]
					length, newi = length - (newi-i) + 1, \
						  i+1
					text = flattext(buf, cp1)
					text = invent_node_names(text)
				else:
					length, endarg = getnextarg(length, buf, pp, afternodenamecmd)
					cp1 = crcopy(pp[afternodenamecmd:endarg])
					del pp[newi:endarg]
					length = length - (endarg-newi)

					pp[i:newi] = [\
						  chunk(GROUP, ch.where, \
						  pp[i:newi])]
					length, newi = length - (newi-i) + 1, \
						  i + 1
					text = flattext(buf, cp1)
				if text[-1] == '.':
					text = text[:-1]
##				print 'FLATTEXT:', `text`
				if text in hist.nodenames:
					print 'WARNING: node name ' + `text` + ' already used'
					out.doublenodes.append(text)
				else:
					hist.nodenames.append(text)
				text = rm_commas_etc(text)
				pp[i-1:i-1] = [\
					  chunk(CSLINE, ch.where, 'node'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, text+', , ,')\
					  ])]
				i, length = newi+2, length+2

			elif s(buf,ch.data) == 'funcline':
				# fold it to a very short environment
				pp[i-1:i-1] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, hist.command)])]
				i, length = i+2, length+2
				length, i = do_funcdesc(length, buf, pp, i)
				
			elif s(buf,ch.data) == 'dataline':
				pp[i-1:i-1] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, hist.command)])]
				i, length = i+2, length+2
				length, i = do_datadesc(length, buf, pp, i)
				
			elif s(buf,ch.data) == 'excline':
				pp[i-1:i-1] = [\
					  chunk(CSLINE, ch.where, 'end'), \
					  chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, hist.command)])]
				i, length = i+2, length+2
				length, i = do_excdesc(length, buf, pp, i)
				
				
			elif s(buf, ch.data) == 'index':
				#\index{A} --->
				# @cindex A
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'cindex'
				length, newi = getnextarg(length, buf, pp, i)

				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)
				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1

			elif s(buf, ch.data) == 'bifuncindex':
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'findex'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)

				ingroupch.append(chunk(PLAIN, ch.where, ' '))
				ingroupch.append(chunk(CSNAME, ch.where, 'r'))
				ingroupch.append(chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, \
					  '(built-in function)')]))

				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1
				
				
			elif s(buf, ch.data) == 'opindex':
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'findex'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)

				ingroupch.append(chunk(PLAIN, ch.where, ' '))
				ingroupch.append(chunk(CSNAME, ch.where, 'r'))
				ingroupch.append(chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, \
					  '(operator)')]))

				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1


			elif s(buf, ch.data) == 'bimodindex':
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'pindex'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)

				ingroupch.append(chunk(PLAIN, ch.where, ' '))
				ingroupch.append(chunk(CSNAME, ch.where, 'r'))
				ingroupch.append(chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, \
					  '(built-in)')]))

				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1

			elif s(buf, ch.data) == 'sectcode':
				ch.data = 'code'


			elif s(buf, ch.data) == 'stmodindex':
				ch.chtype = chunk_type(CSLINE)
				# use the program index as module index
				ch.data = 'pindex'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = pp[i:newi]
				del pp[i:newi]
				length = length - (newi-i)

				ingroupch.append(chunk(PLAIN, ch.where, ' '))
				ingroupch.append(chunk(CSNAME, ch.where, 'r'))
				ingroupch.append(chunk(GROUP, ch.where, [\
					  chunk(PLAIN, ch.where, \
					  '(standard)')]))

				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				length, i = length+1, i+1


			elif s(buf, ch.data) == 'stindex':
				# XXX must actually go to newindex st
				wh = ch.where
				ch.chtype = chunk_type(CSLINE)
				ch.data = 'cindex'
				length, newi = getnextarg(length, buf, pp, i)
				ingroupch = [chunk(CSNAME, wh, 'code'), \
					  chunk(GROUP, wh, pp[i:newi])]

				del pp[i:newi]
				length = length - (newi-i)

				t = ingroupch[:]
				t.append(chunk(PLAIN, wh, ' statement'))

				pp.insert(i, chunk(GROUP, wh, t))
				i, length = i+1, length+1

				pp.insert(i, chunk(CSLINE, wh, 'cindex'))
				i, length = i+1, length+1

				t = ingroupch[:]
				t.insert(0, chunk(PLAIN, wh, 'statement, '))
				
				pp.insert(i, chunk(GROUP, wh, t))
				i, length = i+1, length+1
				

			elif s(buf, ch.data) == 'indexii':
				#\indexii{A}{B} --->
				# @cindex A B
				# @cindex B, A
				length, newi = getnextarg(length, buf, pp, i)
				cp11 = pp[i:newi]
				cp21 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp12 = pp[i:newi]
				cp22 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)

				ch.chtype = chunk_type(CSLINE)
				ch.data = 'cindex'
				pp.insert(i, chunk(GROUP, ch.where, cp11 + [\
					  chunk(PLAIN, ch.where, ' ')] + cp12))
				i, length = i+1, length+1
				pp[i:i] = [chunk(CSLINE, ch.where, 'cindex'), \
					  chunk(GROUP, ch.where, cp22 + [\
					  chunk(PLAIN, ch.where, ', ')]+ cp21)]
				i, length = i+2, length+2

			elif s(buf, ch.data) == 'indexiii':
				length, newi = getnextarg(length, buf, pp, i)
				cp11 = pp[i:newi]
				cp21 = crcopy(pp[i:newi])
				cp31 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp12 = pp[i:newi]
				cp22 = crcopy(pp[i:newi])
				cp32 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp13 = pp[i:newi]
				cp23 = crcopy(pp[i:newi])
				cp33 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)

				ch.chtype = chunk_type(CSLINE)
				ch.data = 'cindex'
				pp.insert(i, chunk(GROUP, ch.where, cp11 + [\
					  chunk(PLAIN, ch.where, ' ')] + cp12 \
					  + [chunk(PLAIN, ch.where, ' ')] \
					  + cp13))
				i, length = i+1, length+1
				pp[i:i] = [chunk(CSLINE, ch.where, 'cindex'), \
					  chunk(GROUP, ch.where, cp22 + [\
					  chunk(PLAIN, ch.where, ' ')]+ cp23\
					  + [chunk(PLAIN, ch.where, ', ')] +\
					  cp21)]
				i, length = i+2, length+2
				pp[i:i] = [chunk(CSLINE, ch.where, 'cindex'), \
					  chunk(GROUP, ch.where, cp33 + [\
					  chunk(PLAIN, ch.where, ', ')]+ cp31\
					  + [chunk(PLAIN, ch.where, ' ')] +\
					  cp32)]
				i, length = i+2, length+2
				
				
			elif s(buf, ch.data) == 'indexiv':
				length, newi = getnextarg(length, buf, pp, i)
				cp11 = pp[i:newi]
				cp21 = crcopy(pp[i:newi])
				cp31 = crcopy(pp[i:newi])
				cp41 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp12 = pp[i:newi]
				cp22 = crcopy(pp[i:newi])
				cp32 = crcopy(pp[i:newi])
				cp42 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp13 = pp[i:newi]
				cp23 = crcopy(pp[i:newi])
				cp33 = crcopy(pp[i:newi])
				cp43 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)
				length, newi = getnextarg(length, buf, pp, i)
				cp14 = pp[i:newi]
				cp24 = crcopy(pp[i:newi])
				cp34 = crcopy(pp[i:newi])
				cp44 = crcopy(pp[i:newi])
				del pp[i:newi]
				length = length - (newi-i)

				ch.chtype = chunk_type(CSLINE)
				ch.data = 'cindex'
				ingroupch = cp11 + \
					  spacech + cp12 + \
					  spacech + cp13 + \
					  spacech + cp14
				pp.insert(i, chunk(GROUP, ch.where, ingroupch))
				i, length = i+1, length+1
				ingroupch = cp22 + \
					  spacech + cp23 + \
					  spacech + cp24 + \
					  commach + cp21
				pp[i:i] = cindexch + [\
					  chunk(GROUP, ch.where, ingroupch)]
				i, length = i+2, length+2
				ingroupch = cp33 + \
					  spacech + cp34 + \
					  commach + cp31 + \
					  spacech + cp32
				pp[i:i] = cindexch + [\
					  chunk(GROUP, ch.where, ingroupch)]
				i, length = i+2, length+2
				ingroupch = cp44 + \
					  commach + cp41 + \
					  spacech + cp42 + \
					  spacech + cp43
				pp[i:i] = cindexch + [\
					  chunk(GROUP, ch.where, ingroupch)]
				i, length = i+2, length+2
				
				

			else:
				print 'don\'t know what to do with keyword ' + `s(buf, ch.data)`


	
re_atsign = regex.compile('[@{}]')
re_newline = regex.compile('\n')

def dumpit(buf, wm, pp):

	global out
	
	i, length = 0, len(pp)

	addspace = 0
	
	while 1:
		if len(pp) != length:
			raise 'FATAL', 'inconsistent length'
		if i == length:
			break
		ch = pp[i]
		i = i + 1

		if addspace:
			dospace = 1
			addspace = 0
		else:
			dospace = 0

		if ch.chtype == chunk_type(CSNAME):
			wm('@' + s(buf, ch.data))
			if s(buf, ch.data) == 'node' and \
				  pp[i].chtype == chunk_type(PLAIN) and \
				  s(buf, pp[i].data) in out.doublenodes:
				##XXX doesnt work yet??
				wm(' ZZZ-' + zfill(`i`, 4))
			if s(buf, ch.data)[0] in string.letters:
				addspace = 1
		elif ch.chtype == chunk_type(PLAIN):
			if dospace and s(buf, ch.data) not in (' ', '\t'):
				wm(' ')
			text = s(buf, ch.data)
			while 1:
				pos = re_atsign.search(text)
				if pos < 0:
					break
				wm(text[:pos] + '@' + text[pos])
				text = text[pos+1:]
			wm(text)
		elif ch.chtype == chunk_type(GROUP):
			wm('{')
			dumpit(buf, wm, ch.data)
			wm('}')
		elif ch.chtype == chunk_type(DENDLINE):
			wm('\n\n')
			while i != length and pp[i].chtype in \
				  (chunk_type(DENDLINE), chunk_type(ENDLINE)):
				i = i + 1
		elif ch.chtype == chunk_type(OTHER):
			wm(s(buf, ch.data))
		elif ch.chtype == chunk_type(ACTIVE):
			wm(s(buf, ch.data))
		elif ch.chtype == chunk_type(ENDLINE):
			wm('\n')
		elif ch.chtype == chunk_type(CSLINE):
			if i >= 2 and pp[i-2].chtype not in \
				  (chunk_type(ENDLINE), chunk_type(DENDLINE)) \
				  and (pp[i-2].chtype != chunk_type(PLAIN) \
				  or s(buf, pp[i-2].data)[-1] != '\n'):
				  
				wm('\n')
			wm('@' + s(buf, ch.data))
			if i == length:
				raise error, 'CSLINE expected another chunk'
			if pp[i].chtype != chunk_type(GROUP):
				raise error, 'CSLINE expected GROUP'
			if type(pp[i].data) != type([]):
				raise error, 'GROUP chould contain []-data'
			
			wobj = Wobj().init()
			dumpit(buf, wobj.write, pp[i].data)
			i = i + 1
			text = wobj.data
			del wobj
			if text:
				wm(' ')
				while 1:
					pos = re_newline.search(text)
					if pos < 0:
						break
					print 'WARNING: found newline in csline arg'
					wm(text[:pos] + ' ')
					text = text[pos+1:]
				wm(text)
			if i >= length or \
				  pp[i].chtype not in (chunk_type(CSLINE), \
				  chunk_type(ENDLINE), chunk_type(DENDLINE)) \
				  and (pp[i].chtype != chunk_type(PLAIN) \
				  or s(buf, pp[i].data)[0] != '\n'):
				wm('\n')
			
		elif ch.chtype == chunk_type(COMMENT):
##			print 'COMMENT: previous chunk =', pp[i-2]
			if pp[i-2].chtype == chunk_type(PLAIN):
				print 'PLAINTEXT =', `s(buf, pp[i-2].data)`
			if s(buf, ch.data) and \
				  regex.match('^[ \t]*$', s(buf, ch.data)) < 0:
				if i >= 2 and pp[i-2].chtype not in \
					  (chunk_type(ENDLINE), chunk_type(DENDLINE)) \
					  and not (pp[i-2].chtype == chunk_type(PLAIN) \
					  and regex.match('\\(.\\|\n\\)*[ \t]*\n$', s(buf, pp[i-2].data)) >= 0):
					print 'ADDING NEWLINE'
					wm('\n')
				wm('@c ' + s(buf, ch.data))
		elif ch.chtype == chunk_type(IGNORE):
			pass
		else:
			try:
				str = `s(buf, ch.data)`
			except TypeError:
				str = `ch.data`
			if len(str) > 400:
				str = str[:400] + '...'
			print 'warning:', ch.chtype, 'not handled, data ' + str



def main():
	outfile = None
	headerfile = 'texipre.dat'
	trailerfile = 'texipost.dat'

	try:
		opts, args = getopt.getopt(sys.argv[1:], 'o:h:t:')
	except getopt.error:
		args = []

	if not args:
		print 'usage: partparse [-o outfile] [-h headerfile]',
		print '[-t trailerfile] file ...'
		sys.exit(2)

	for opt, arg in opts:
		if opt == '-o': outfile = arg
		if opt == '-h': headerfile = arg
		if opt == '-t': trailerfile = arg

	if not outfile:
		root, ext = os.path.splitext(args[0])
		outfile = root + '.texi'

	if outfile in args:
		print 'will not overwrite input file', outfile
		sys.exit(2)

	outf = open(outfile, 'w')
	outf.write(open(headerfile, 'r').read())

	for file in args:
		if len(args) > 1: print '='*20, file, '='*20
		buf = open(file, 'r').read()
		w, pp = parseit(buf)
		startchange()
		changeit(buf, pp)
		dumpit(buf, outf.write, pp)

	outf.write(open(trailerfile, 'r').read())

	outf.close()

main()