Changes between release 2.5.4 (11Sep96) and release 2.5.3:	- Fixed a bug introduced in 2.5.3 that blew it when a call	  to input() occurred at the end of an input file.	- Fixed scanner skeleton so the example in the man page of	  scanning strings using exclusive start conditions works.	- Minor Makefile tweaks.Changes between release 2.5.3 (29May96) and release 2.5.2:	- Some serious bugs in yymore() have been fixed.  In particular,	  when using AT&T-lex-compatibility or %array, you can intermix	  calls to input(), unput(), and yymore().  (This still doesn't	  work for %pointer, and isn't likely to in the future.)	- A bug in handling NUL's in the input stream of scanners using	  REJECT has been fixed.	- The default main() in libfl.a now repeatedly calls yylex() until	  it returns 0, rather than just calling it once.	- Minor tweak for Windows NT Makefile, MISC/NT/Makefile.Changes between release 2.5.2 (25Apr95) and release 2.5.1:	- The --prefix configuration option now works.	- A bug that completely broke the "-Cf" table compression	  option has been fixed.	- A major headache involving "const" declarators and Solaris	  systems has been fixed.	- An octal escape sequence in a flex regular expression must	  now contain only the digits 0-7.	- You can now use "--" on the flex command line to mark the	  end of flex options.	- You can now specify the filename '-' as a synonym for stdin.	- By default, the scanners generated by flex no longer	  statically initialize yyin and yyout to stdin and stdout.	  This change is necessary because in some ANSI environments,	  stdin and stdout are not compile-time constant.  You can	  force the initialization using "%option stdinit" in the first	  section of your flex input.	- "%option nounput" now correctly omits the unput() routine	  from the output.	- "make clean" now removes config.log, config.cache, and the	  flex binary.  The fact that it removes the flex binary means	  you should take care if making changes to scan.l, to make	  sure you don't wind up in a bootstrap problem.	- In general, the Makefile has been reworked somewhat (thanks	  to Francois Pinard) for added flexibility - more changes will	  follow in subsequent releases.	- The .texi and .info files in MISC/texinfo/ have been updated,	  thanks also to Francois Pinard.	- The FlexLexer::yylex(istream* new_in, ostream* new_out) method	  now does not have a default for the first argument, to disambiguate	  it from FlexLexer::yylex().	- A bug in destructing a FlexLexer object before doing any scanning	  with it has been fixed.	- A problem with including FlexLexer.h multiple times has been fixed.	- The alloca() chud necessary to accommodate bison has grown	  even uglier, but hopefully more correct.	- A portability tweak has been added to accommodate compilers that	  use char* generic pointers.	- EBCDIC contact information in the file MISC/EBCDIC has been updated.	- An OS/2 Makefile and config.h for flex 2.5 is now available in	  MISC/OS2/, contributed by Kai Uwe Rommel.	- The descrip.mms file for building flex under VMS has been updated,	  thanks to Pat Rankin.	- The notes on building flex for the Amiga have been updated for	  flex 2.5, contributed by Andreas Scherer.Changes between release 2.5.1 (28Mar95) and release 2.4.7:	- A new concept of "start condition" scope has been introduced.	  A start condition scope is begun with:		<SCs>{	  where SCs is a list of one or more start conditions.  Inside	  the start condition scope, every rule automatically has the	  prefix <SCs> applied to it, until a '}' which matches the	  initial '{'.  So, for example:		<ESC>{			"\\n"	return '\n';			"\\r"	return '\r';			"\\f"	return '\f';			"\\0"	return '\0';		}	  is equivalent to:		<ESC>"\\n"	return '\n';		<ESC>"\\r"	return '\r';		<ESC>"\\f"	return '\f';		<ESC>"\\0"	return '\0';	  As indicated in this example, rules inside start condition scopes	  (and any rule, actually, other than the first) can be indented,	  to better show the extent of the scope.	  Start condition scopes may be nested.	- The new %option directive can be used in the first section of	  a flex scanner to control scanner-generation options.  Most	  options are given simply as names, optionally preceded by the	  word "no" (with no intervening whitespace) to negate their	  meaning.  Some are equivalent to flex flags, so putting them	  in your scanner source is equivalent to always specifying	  the flag (%option's take precedence over flags):		7bit	-7 option		8bit	-8 option		align	-Ca option		backup	-b option		batch	-B option		c++	-+ option		caseful	opposite of -i option (caseful is the default);		case-sensitive	same as above		caseless	-i option;		case-insensitive	same as above		debug	-d option		default	opposite of -s option		ecs	-Ce option		fast	-F option		full	-f option		interactive	-I option		lex-compat	-l option		meta-ecs	-Cm option		perf-report	-p option		read	-Cr option		stdout	-t option		verbose	-v option		warn	opposite of -w option (so use "%option nowarn" for -w)		array	equivalent to "%array"		pointer	equivalent to "%pointer" (default)	  Some provide new features:		always-interactive	generate a scanner which always			considers its input "interactive" (no call to isatty()			will be made when the scanner runs)		main	supply a main program for the scanner, which			simply calls yylex().  Implies %option noyywrap.		never-interactive	generate a scanner which never			considers its input "interactive" (no call to isatty()			will be made when the scanner runs)		stack	if set, enable start condition stacks (see below)		stdinit	if unset ("%option nostdinit"), initialize yyin			and yyout statically to nil FILE* pointers, instead			of stdin and stdout		yylineno	if set, keep track of the current line			number in global yylineno (this option is expensive			in terms of performance).  The line number is available			to C++ scanning objects via the new member function			lineno().		yywrap	if unset ("%option noyywrap"), scanner does not			call yywrap() upon EOF but simply assumes there			are no more files to scan	  Flex scans your rule actions to determine whether you use the	  REJECT or yymore features (this is not new).  Two %options can be	  used to override its decision, either by setting them to indicate	  the feature is indeed used, or unsetting them to indicate it	  actually is not used:		reject		yymore	  Three %option's take string-delimited values, offset with '=':		outfile="<name>"	equivalent to -o<name>		prefix="<name>"		equivalent to -P<name>		yyclass="<name>"	set the name of the C++ scanning class					(see below)	  A number of %option's are available for lint purists who	  want to suppress the appearance of unneeded routines in	  the generated scanner.  Each of the following, if unset,	  results in the corresponding routine not appearing in the	  generated scanner:		input, unput		yy_push_state, yy_pop_state, yy_top_state		yy_scan_buffer, yy_scan_bytes, yy_scan_string	  You can specify multiple options with a single %option directive,	  and multiple directives in the first section of your flex input file.	- The new function:		YY_BUFFER_STATE yy_scan_string( const char *str )	  returns a YY_BUFFER_STATE (which also becomes the current input	  buffer) for scanning the given string, which occurs starting	  with the next call to yylex().  The string must be NUL-terminated.	  A related function:		YY_BUFFER_STATE yy_scan_bytes( const char *bytes, int len )	  creates a buffer for scanning "len" bytes (including possibly NUL's)	  starting at location "bytes".	  Note that both of these functions create and scan a *copy* of	  the string/bytes.  (This may be desirable, since yylex() modifies	  the contents of the buffer it is scanning.)  You can avoid the	  copy by using:		YY_BUFFER_STATE yy_scan_buffer( char *base, yy_size_t size )	  which scans in place the buffer starting at "base", consisting	  of "size" bytes, the last two bytes of which *must* be	  YY_END_OF_BUFFER_CHAR (these bytes are not scanned; thus, scanning	  consists of base[0] through base[size-2], inclusive).  If you	  fail to set up "base" in this manner, yy_scan_buffer returns a	  nil pointer instead of creating a new input buffer.	  The type yy_size_t is an integral type to which you can cast	  an integer expression reflecting the size of the buffer.	- Three new routines are available for manipulating stacks of	  start conditions:		void yy_push_state( int new_state )	  pushes the current start condition onto the top of the stack	  and BEGIN's "new_state" (recall that start condition names are	  also integers).		void yy_pop_state()	  pops the top of the stack and BEGIN's to it, and		int yy_top_state()	  returns the top of the stack without altering the stack's	  contents.	  The start condition stack grows dynamically and so has no built-in	  size limitation.  If memory is exhausted, program execution	  is aborted.	  To use start condition stacks, your scanner must include	  a "%option stack" directive.	- flex now supports POSIX character class expressions.  These	  are expressions enclosed inside "[:" and ":]" delimiters (which	  themselves must appear between the '[' and ']' of a character	  class; other elements may occur inside the character class, too).	  The expressions flex recognizes are:		[:alnum:] [:alpha:] [:blank:] [:cntrl:] [:digit:] [:graph:]			[:lower:] [:print:] [:punct:] [:space:] [:upper:] [:xdigit:]	  These expressions all designate a set of characters equivalent to	  the corresponding isXXX function (for example, [:alnum:] designates	  those characters for which isalnum() returns true - i.e., any	  alphabetic or numeric).  Some systems don't provide isblank(),	  so flex defines [:blank:] as a blank or a tab.	  For example, the following character classes are all equivalent:		[[:alnum:]]		[[:alpha:][:digit:]		[[:alpha:]0-9]		[a-zA-Z0-9]	  If your scanner is case-insensitive (-i flag), then [:upper:]	  and [:lower:] are equivalent to [:alpha:].	- The promised rewrite of the C++ FlexLexer class has not yet	  been done.  Support for FlexLexer is limited at the moment to	  fixing show-stopper bugs, so, for example, the new functions	  yy_scan_string() & friends are not available to FlexLexer	  objects.	- The new macro		yy_set_interactive(is_interactive)	  can be used to control whether the current buffer is considered	  "interactive".  An interactive buffer is processed more slowly,	  but must be used when the scanner's input source is indeed	  interactive to avoid problems due to waiting to fill buffers	  (see the discussion of the -I flag in flex.1).  A non-zero value