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+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
+	  in the macro invocation marks the buffer as interactive, a zero
+	  value as non-interactive.  Note that use of this macro overrides
+	  "%option always-interactive" or "%option never-interactive".
+
+	  yy_set_interactive() must be invoked prior to beginning to
+	  scan the buffer.
+
+	- The new macro
+
+		yy_set_bol(at_bol)
+
+	  can be used to control whether the current buffer's scanning
+	  context for the next token match is done as though at the
+	  beginning of a line (non-zero macro argument; makes '^' anchored
+	  rules active) or not at the beginning of a line (zero argument,
+	  '^' rules inactive).
+
+	- Related to this change, the mechanism for determining when a scan is
+	  starting at the beginning of a line has changed.  It used to be
+	  that '^' was active iff the character prior to that at which the
+	  scan started was a newline.  The mechanism now is that '^' is
+	  active iff the last token ended in a newline (or the last call to
+	  input() returned a newline).  For most users, the difference in
+	  mechanisms is negligible.  Where it will make a difference,
+	  however, is if unput() or yyless() is used to alter the input
+	  stream.  When in doubt, use yy_set_bol().
+
+	- The new beginning-of-line mechanism involved changing some fairly
+	  twisted code, so it may have introduced bugs - beware ...
+
+	- The macro YY_AT_BOL() returns true if the next token scanned from
+	  the current buffer will have '^' rules active, false otherwise.
+
+	- The new function
+
+		void yy_flush_buffer( struct yy_buffer_state* b )
+
+	  flushes the contents of the current buffer (i.e., next time
+	  the scanner attempts to match a token using b as the current
+	  buffer, it will begin by invoking YY_INPUT to fill the buffer).
+	  This routine is also available to C++ scanners (unlike some
+	  of the other new routines).
+
+	  The related macro
+
+		YY_FLUSH_BUFFER
+
+	  flushes the contents of the current buffer.
+
+	- A new "-ooutput" option writes the generated scanner to "output".
+	  If used with -t, the scanner is still written to stdout, but
+	  its internal #line directives (see previous item) use "output".
+
+	- Flex now generates #line directives relating the code it
+	  produces to the output file; this means that error messages
+	  in the flex-generated code should be correctly pinpointed.
+
+	- When generating #line directives, filenames with embedded '\'s
+	  have those characters escaped (i.e., turned into '\\').  This
+	  feature helps with reporting filenames for some MS-DOS and OS/2
+	  systems.
+
+	- The FlexLexer class includes two new public member functions:
+
+		virtual void switch_streams( istream* new_in = 0,
+						ostream* new_out = 0 )
+
+	  reassigns yyin to new_in (if non-nil) and yyout to new_out
+	  (ditto), deleting the previous input buffer if yyin is
+	  reassigned.  It is used by:
+
+		int yylex( istream* new_in = 0, ostream* new_out = 0 )
+
+	  which first calls switch_streams() and then returns the value
+	  of calling yylex().
+
+	- C++ scanners now have yy_flex_debug as a member variable of
+	  FlexLexer rather than a global, and member functions for testing
+	  and setting it.
+
+	- When generating a C++ scanning class, you can now use
+
+		%option yyclass="foo"
+
+	  to inform flex that you have derived "foo" as a subclass of
+	  yyFlexLexer, so flex will place your actions in the member
+	  function foo::yylex() instead of yyFlexLexer::yylex().  It also
+	  generates a yyFlexLexer::yylex() member function that generates a
+	  run-time error if called (by invoking yyFlexLexer::LexerError()).
+	  This feature is necessary if your subclass "foo" introduces some
+	  additional member functions or variables that you need to access
+	  from yylex().
+
+	- Current texinfo files in MISC/texinfo, contributed by Francois
+	  Pinard.
+
+	- You can now change the name "flex" to something else (e.g., "lex")
+	  by redefining $(FLEX) in the Makefile.
+
+	- Two bugs (one serious) that could cause "bigcheck" to fail have
+	  been fixed.
+
+	- A number of portability/configuration changes have been made
+	  for easier portability.
+
+	- You can use "YYSTATE" in your scanner as an alias for YY_START
+	  (for AT&T lex compatibility).
+
+	- input() now maintains yylineno.
+
+	- input() no longer trashes yytext.
+
+	- interactive scanners now read characters in YY_INPUT up to a
+	  newline, a large performance gain.
+
+	- C++ scanner objects now work with the -P option.  You include
+	  <FlexLexer.h> once per scanner - see comments in <FlexLexer.h>
+	  (or flex.1) for details.
+
+	- C++ FlexLexer objects now use the "cerr" stream to report -d output
+	  instead of stdio.
+
+	- The -c flag now has its full glorious POSIX interpretation (do
+	  nothing), rather than being interpreted as an old-style -C flag.
+
+	- Scanners generated by flex now include two #define's giving
+	  the major and minor version numbers (YY_FLEX_MAJOR_VERSION,
+	  YY_FLEX_MINOR_VERSION).  These can then be tested to see
+	  whether certain flex features are available.
+
+	- Scanners generated using -l lex compatibility now have the symbol
+	  YY_FLEX_LEX_COMPAT #define'd.
+
+	- When initializing (i.e., yy_init is non-zero on entry to yylex()),
+	  generated scanners now set yy_init to zero before executing
+	  YY_USER_INIT.  This means that you can set yy_init back to a
+	  non-zero value in YY_USER_INIT if you need the scanner to be
+	  reinitialized on the next call.
+
+	- You can now use "#line" directives in the first section of your
+	  scanner specification.
+
+	- When generating full-table scanners (-Cf), flex now puts braces
+	  around each row of the 2-d array initialization, to silence warnings
+	  on over-zealous compilers.
+
+	- Improved support for MS-DOS.  The flex sources have been successfully
+	  built, unmodified, for Borland 4.02 (all that's required is a
+	  Borland Makefile and config.h file, which are supplied in
+	  MISC/Borland - contributed by Terrence O Kane).
+
+	- Improved support for Macintosh using Think C - the sources should
+	  build for this platform "out of the box".  Contributed by Scott
+	  Hofmann.
+
+	- Improved support for VMS, in MISC/VMS/, contributed by Pat Rankin.
+
+	- Support for the Amiga, in MISC/Amiga/, contributed by Andreas
+	  Scherer.  Note that the contributed files were developed for
+	  flex 2.4 and have not been tested with flex 2.5.
+
+	- Some notes on support for the NeXT, in MISC/NeXT, contributed
+	  by Raf Schietekat.
+
+	- The MISC/ directory now includes a preformatted version of flex.1
+	  in flex.man, and pre-yacc'd versions of parse.y in parse.{c,h}.
+
+	- The flex.1 and flexdoc.1 manual pages have been merged.  There
+	  is now just one document, flex.1, which includes an overview
+	  at the beginning to help you find the section you need.
+
+	- Documentation now clarifies that start conditions persist across
+	  switches to new input files or different input buffers.  If you
+	  want to e.g., return to INITIAL, you must explicitly do so.
+
+	- The "Performance Considerations" section of the manual has been
+	  updated.
+
+	- Documented the "yy_act" variable, which when YY_USER_ACTION is
+	  invoked holds the number of the matched rule, and added an
+	  example of using yy_act to profile how often each rule is matched.
+
+	- Added YY_NUM_RULES, a definition that gives the total number
+	  of rules in the file, including the default rule (even if you
+	  use -s).
+
+	- Documentation now clarifies that you can pass a nil FILE* pointer
+	  to yy_create_buffer() or yyrestart() if you've arrange YY_INPUT
+	  to not need yyin.
+
+	- Documentation now clarifies that YY_BUFFER_STATE is a pointer to
+	  an opaque "struct yy_buffer_state".
+
+	- Documentation now stresses that you gain the benefits of removing
+	  backing-up states only if you remove *all* of them.
+
+	- Documentation now points out that traditional lex allows you
+	  to put the action on a separate line from the rule pattern if
+	  the pattern has trailing whitespace (ugh!), but flex doesn't
+	  support this.
+
+	- A broken example in documentation of the difference between
+	  inclusive and exclusive start conditions is now fixed.
+
+	- Usage (-h) report now goes to stdout.
+
+	- Version (-V) info now goes to stdout.
+
+	- More #ifdef chud has been added to the parser in attempt to
+	  deal with bison's use of alloca().
+
+	- "make clean" no longer deletes emacs backup files (*~).
+
+	- Some memory leaks have been fixed.
+
+	- A bug was fixed in which dynamically-expanded buffers were
+	  reallocated a couple of bytes too small.
+
+	- A bug was fixed which could cause flex to read and write beyond
+	  the end of the input buffer.
+
+	- -S will not be going away.
+
+
+Changes between release 2.4.7 (03Aug94) and release 2.4.6:
+
+	- Fixed serious bug in reading multiple files.
+
+	- Fixed bug in scanning NUL's.
+
+	- Fixed bug in input() returning 8-bit characters.
+
+	- Fixed bug in matching text with embedded NUL's when
+	  using %array or lex compatibility.
+
+	- Fixed multiple invocations of YY_USER_ACTION when using '|'
+	  continuation action.
+
+	- Minor prototyping fixes.
+
+Changes between release 2.4.6 (04Jan94) and release 2.4.5:
+
+	- Linking with -lfl no longer required if your program includes
+	  its own yywrap() and main() functions.  (This change will cause
+	  problems if you have a non-ANSI compiler on a system for which
+	  sizeof(int) != sizeof(void*) or sizeof(int) != sizeof(size_t).)
+
+	- The use of 'extern "C++"' in FlexLexer.h has been modified to
+	  get around an incompatibility with g++'s header files.
+
+Changes between release 2.4.5 (11Dec93) and release 2.4.4:
+
+	- Fixed bug breaking C++ scanners that use REJECT or variable
+	  trailing context.
+
+	- Fixed serious input problem for interactive scanners on
+	  systems for which char is unsigned.
+
+	- Fixed bug in incorrectly treating '$' operator as variable
+	  trailing context.
+
+	- Fixed bug in -CF table representation that could lead to
+	  corrupt tables.
+
+	- Fixed fairly benign memory leak.
+
+	- Added `extern "C++"' wrapper to FlexLexer.h header.  This
+	  should overcome the g++ 2.5.X problems mentioned in the
+	  NEWS for release 2.4.3.
+
+	- Changed #include of FlexLexer.h to use <> instead of "".
+
+	- Added feature to control whether the scanner attempts to
+	  refill the input buffer once it's exhausted.  This feature
+	  will be documented in the 2.5 release.
+
+
+Changes between release 2.4.4 (07Dec93) and release 2.4.3:
+
+	- Fixed two serious bugs in scanning 8-bit characters.
+
+	- Fixed bug in YY_USER_ACTION that caused it to be executed
+	  inappropriately (on the scanner's own internal actions, and
+	  with incorrect yytext/yyleng values).
+
+	- Fixed bug in pointing yyin at a new file and resuming scanning.
+
+	- Portability fix regarding min/max/abs macros conflicting with
+	  function definitions in standard header files.
+
+	- Added a virtual LexerError() method to the C++ yyFlexLexer class
+	  for reporting error messages instead of always using cerr.
+
+	- Added warning in flexdoc that the C++ scanning class is presently
+	  experimental and subject to considerable change between major
+	  releases.
+
+
+Changes between release 2.4.3 (03Dec93) and release 2.4.2:
+
+	- Fixed bug causing fatal scanner messages to fail to print.
+
+	- Fixed things so FlexLexer.h can be included in other C++
+	  sources.  One side-effect of this change is that -+ and -CF
+	  are now incompatible.
+
+	- libfl.a now supplies private versions of the the <string.h>/
+	  <strings.h> string routines needed by flex and the scanners
+	  it generates, to enhance portability to some BSD systems.
+
+	- More robust solution to 2.4.2's flexfatal() bug fix.
+
+	- Added ranlib of installed libfl.a.
+
+	- Some lint tweaks.
+
+	- NOTE: problems have been encountered attempting to build flex
+	  C++ scanners using g++ version 2.5.X.  The problem is due to an
+	  unfortunate heuristic in g++ 2.5.X that attempts to discern between
+	  C and C++ headers.  Because FlexLexer.h is installed (by default)
+	  in /usr/local/include and not /usr/local/lib/g++-include, g++ 2.5.X
+	  decides that it's a C header :-(.  So if you have problems, install
+	  the header in /usr/local/lib/g++-include instead.
+
+
+Changes between release 2.4.2 (01Dec93) and release 2.4.1:
+
+	- Fixed bug in libfl.a referring to non-existent "flexfatal" function.
+
+	- Modified to produce both compress'd and gzip'd tar files for
+	  distributions (you probably don't care about this change!).
+
+
+Changes between release 2.4.1 (30Nov93) and release 2.3.8:
+
+	- The new '-+' flag instructs flex to generate a C++ scanner class
+	  (thanks to Kent Williams).  flex writes an implementation of the
+	  class defined in FlexLexer.h to lex.yy.cc.  You may include
+	  multiple scanner classes in your program using the -P flag.  Note
+	  that the scanner class also provides a mechanism for creating
+	  reentrant scanners.  The scanner class uses C++ streams for I/O
+	  instead of FILE*'s (thanks to Tom Epperly).  If the flex executable's
+	  name ends in '+' then the '-+' flag is automatically on, so creating
+	  a symlink or copy of "flex" to "flex++" results in a version of
+	  flex that can be used exclusively for C++ scanners.
+
+	  Note that without the '-+' flag, flex-generated scanners can still
+	  be compiled using C++ compilers, though they use FILE*'s for I/O
+	  instead of streams.
+
+	  See the "GENERATING C++ SCANNERS" section of flexdoc for details.
+
+	- The new '-l' flag turns on maximum AT&T lex compatibility.  In
+	  particular, -l includes support for "yylineno" and makes yytext
+	  be an array instead of a pointer.  It does not, however, do away
+	  with all incompatibilities.  See the "INCOMPATIBILITIES WITH LEX
+	  AND POSIX" section of flexdoc for details.
+
+	- The new '-P' option specifies a prefix to use other than "yy"
+	  for the scanner's globally-visible variables, and for the
+	  "lex.yy.c" filename.  Using -P you can link together multiple
+	  flex scanners in the same executable.
+
+	- The distribution includes a "texinfo" version of flexdoc.1,
+	  contributed by Roland Pesch (thanks also to Marq Kole, who
+	  contributed another version).  It has not been brought up to
+	  date, but reflects version 2.3.  See MISC/flex.texinfo.
+
+	  The flex distribution will soon include G.T. Nicol's flex
+	  manual; he is presently bringing it up-to-date for version 2.4.
+
+	- yywrap() is now a function, and you now *must* link flex scanners
+	  with libfl.a.
+
+	- Site-configuration is now done via an autoconf-generated
+	  "configure" script contributed by Francois Pinard.
+
+	- Scanners now use fread() (or getc(), if interactive) and not
+	  read() for input.  A new "table compression" option, -Cr,
+	  overrides this change and causes the scanner to use read()
+	  (because read() is a bit faster than fread()).  -f and -F
+	  are now equivalent to -Cfr and -CFr; i.e., they imply the
+	  -Cr option.
+
+	- In the blessed name of POSIX compliance, flex supports "%array"
+	  and "%pointer" directives in the definitions (first) section of
+	  the scanner specification.  The former specifies that yytext
+	  should be an array (of size YYLMAX), the latter, that it should
+	  be a pointer.  The array version of yytext is universally slower
+	  than the pointer version, but has the advantage that its contents
+	  remain unmodified across calls to input() and unput() (the pointer
+	  version of yytext is, still, trashed by such calls).
+
+	  "%array" cannot be used with the '-+' C++ scanner class option.
+
+	- The new '-Ca' option directs flex to trade off memory for
+	  natural alignment when generating a scanner's tables.  In
+	  particular, table entries that would otherwise be "short"
+	  become "long".
+
+	- The new '-h' option produces a summary of the flex flags.
+
+	- The new '-V' option reports the flex version number and exits.
+
+	- The new scanner macro YY_START returns an integer value
+	  corresponding to the current start condition.  You can return
+	  to that start condition by passing the value to a subsequent
+	  "BEGIN" action.  You also can implement "start condition stacks"
+	  by storing the values in an integer stack.
+
+	- You can now redefine macros such as YY_INPUT by just #define'ing
+	  them to some other value in the first section of the flex input;
+	  no need to first #undef them.
+
+	- flex now generates warnings for rules that can't be matched.
+	  These warnings can be turned off using the new '-w' flag.  If
+	  your scanner uses REJECT then you will not get these warnings.
+
+	- If you specify the '-s' flag but the default rule can be matched,
+	  flex now generates a warning.
+
+	- "yyleng" is now a global, and may be modified by the user (though
+	  doing so and then using yymore() will yield weird results).
+
+	- Name definitions in the first section of a scanner specification
+	  can now include a leading '^' or trailing '$' operator.  In this
+	  case, the definition is *not* pushed back inside of parentheses.
+
+	- Scanners with compressed tables are now "interactive" (-I option)
+	  by default.  You can suppress this attribute (which makes them
+	  run slightly slower) using the new '-B' flag.
+
+	- Flex now generates 8-bit scanners by default, unless you use the
+	  -Cf or -CF compression options (-Cfe  and -CFe result in 8-bit
+	  scanners).  You can force it to generate a 7-bit scanner using
+	  the new '-7' flag.  You can build flex to generate 8-bit scanners
+	  for -Cf and -CF, too, by adding -DDEFAULT_CSIZE=256 to CFLAGS
+	  in the Makefile.
+
+	- You no longer need to call the scanner routine yyrestart() to
+	  inform the scanner that you have switched to a new file after
+	  having seen an EOF on the current input file.  Instead, just
+	  point yyin at the new file and continue scanning.
+
+	- You no longer need to invoke YY_NEW_FILE in an <<EOF>> action
+	  to indicate you wish to continue scanning.  Simply point yyin
+	  at a new file.
+
+	- A leading '#' no longer introduces a comment in a flex input.
+
+	- flex no longer considers formfeed ('\f') a whitespace character.
+
+	- %t, I'm happy to report, has been nuked.
+
+	- The '-p' option may be given twice ('-pp') to instruct flex to
+	  report minor performance problems as well as major ones.
+
+	- The '-v' verbose output no longer includes start/finish time
+	  information.
+
+	- Newlines in flex inputs can optionally include leading or
+	  trailing carriage-returns ('\r'), in support of several PC/Mac
+	  run-time libraries that automatically include these.
+
+	- A start condition of the form "<*>" makes the following rule
+	  active in every start condition, whether exclusive or inclusive.
+
+	- The following items have been corrected in the flex documentation:
+
+		- '-C' table compression options *are* cumulative.
+
+		- You may modify yytext but not lengthen it by appending
+		  characters to the end.  Modifying its final character
+		  will affect '^' anchoring for the next rule matched
+		  if the character is changed to or from a newline.
+
+		- The term "backtracking" has been renamed "backing up",
+		  since it is a one-time repositioning and not a repeated
+		  search.  What used to be the "lex.backtrack" file is now
+		  "lex.backup".
+
+		- Unindented "/* ... */" comments are allowed in the first
+		  flex input section, but not in the second.
+
+		- yyless() can only be used in the flex input source, not
+		  externally.
+
+		- You can use "yyrestart(yyin)" to throw away the
+		  current contents of the input buffer.
+
+		- To write high-speed scanners, attempt to match as much
+		  text as possible with each rule.  See MISC/fastwc/README
+		  for more information.
+
+		- Using the beginning-of-line operator ('^') is fairly
+		  cheap.  Using unput() is expensive.  Using yyless() is
+		  cheap.
+
+		- An example of scanning strings with embedded escape
+		  sequences has been added.
+
+		- The example of backing-up in flexdoc was erroneous; it
+		  has been corrected.
+
+	- A flex scanner's internal buffer now dynamically grows if needed
+	  to match large tokens.  Note that growing the buffer presently
+	  requires rescanning the (large) token, so consuming a lot of
+	  text this way is a slow process.  Also note that presently the
+	  buffer does *not* grow if you unput() more text than can fit
+	  into the buffer.
+
+	- The MISC/ directory has been reorganized; see MISC/README for
+	  details.
+
+	- yyless() can now be used in the third (user action) section
+	  of a scanner specification, thanks to Ceriel Jacobs.  yyless()
+	  remains a macro and cannot be used outside of the scanner source.
+
+	- The skeleton file is no longer opened at run-time, but instead
+	  compiled into a large string array (thanks to John Gilmore and
+	  friends at Cygnus).  You can still use the -S flag to point flex
+	  at a different skeleton file.
+
+	- flex no longer uses a temporary file to store the scanner's
+	  actions.
+
+	- A number of changes have been made to decrease porting headaches.
+	  In particular, flex no longer uses memset() or ctime(), and
+	  provides a single simple mechanism for dealing with C compilers
+	  that still define malloc() as returning char* instead of void*.
+
+	- Flex now detects if the scanner specification requires the -8 flag
+	  but the flag was not given or on by default.
+
+	- A number of table-expansion fencepost bugs have been fixed,
+	  making flex more robust for generating large scanners.
+
+	- flex more consistently identifies the location of errors in
+	  its input.
+
+	- YY_USER_ACTION is now invoked only for "real" actions, not for
+	  internal actions used by the scanner for things like filling
+	  the buffer or handling EOF.
+
+	- The rule "[^]]" now matches any character other than a ']';
+	  formerly it matched any character at all followed by a ']'.
+	  This change was made for compatibility with AT&T lex.
+
+	- A large number of miscellaneous bugs have been found and fixed
+	  thanks to Gerhard Wilhelms.
+
+	- The source code has been heavily reformatted, making patches
+	  relative to previous flex releases no longer accurate.
+
+
+Changes between 2.3 Patch #8 (21Feb93) and 2.3 Patch #7:
+
+	- Fixed bugs in dynamic memory allocation leading to grievous
+	  fencepost problems when generating large scanners.
+	- Fixed bug causing infinite loops on character classes with 8-bit
+	  characters in them.
+	- Fixed bug in matching repetitions with a lower bound of 0.
+	- Fixed bug in scanning NUL characters using an "interactive" scanner.
+	- Fixed bug in using yymore() at the end of a file.
+	- Fixed bug in misrecognizing rules with variable trailing context.
+	- Fixed bug compiling flex on Suns using gcc 2.
+	- Fixed bug in not recognizing that input files with the character
+	  ASCII 128 in them require the -8 flag.
+	- Fixed bug that could cause an infinite loop writing out
+	  error messages.
+	- Fixed bug in not recognizing old-style lex % declarations if
+	  followed by a tab instead of a space.
+	- Fixed potential crash when flex terminated early (usually due
+	  to a bad flag) and the -v flag had been given.
+	- Added some missing declarations of void functions.
+	- Changed to only use '\a' for __STDC__ compilers.
+	- Updated mailing addresses.
+
+
+Changes between 2.3 Patch #7 (28Mar91) and 2.3 Patch #6:
+
+	- Fixed out-of-bounds array access that caused bad tables
+	  to be produced on machines where the bad reference happened
+	  to yield a 1.  This caused problems installing or running
+	  flex on some Suns, in particular.
+
+
+Changes between 2.3 Patch #6 (29Aug90) and 2.3 Patch #5:
+
+	- Fixed a serious bug in yymore() which basically made it
+	  completely broken.  Thanks goes to Jean Christophe of
+	  the Nethack development team for finding the problem
+	  and passing along the fix.
+
+
+Changes between 2.3 Patch #5 (16Aug90) and 2.3 Patch #4:
+
+	- An up-to-date version of initscan.c so "make test" will
+	  work after applying the previous patches
+
+
+Changes between 2.3 Patch #4 (14Aug90) and 2.3 Patch #3:
+
+	- Fixed bug in hexadecimal escapes which allowed only digits,
+	  not letters, in escapes
+	- Fixed bug in previous "Changes" file!
+
+
+Changes between 2.3 Patch #3 (03Aug90) and 2.3 Patch #2:
+
+	- Correction to patch #2 for gcc compilation; thanks goes to
+	  Paul Eggert for catching this.
+
+
+Changes between 2.3 Patch #2 (02Aug90) and original 2.3 release:
+
+	- Fixed (hopefully) headaches involving declaring malloc()
+	  and free() for gcc, which defines __STDC__ but (often) doesn't
+	  come with the standard include files such as <stdlib.h>.
+	  Reordered #ifdef maze in the scanner skeleton in the hope of
+	  getting the declarations right for cfront and g++, too.
+
+	- Note that this patch supercedes patch #1 for release 2.3,
+	  which was never announced but was available briefly for
+	  anonymous ftp.
+
+
+Changes between 2.3 (full) release of 28Jun90 and 2.2 (alpha) release:
+
+User-visible:
+
+	- A lone <<EOF>> rule (that is, one which is not qualified with
+	  a list of start conditions) now specifies the EOF action for
+	  *all* start conditions which haven't already had <<EOF>> actions
+	  given.  To specify an end-of-file action for just the initial
+	  state, use <INITIAL><<EOF>>.
+
+	- -d debug output is now contigent on the global yy_flex_debug
+	  being set to a non-zero value, which it is by default.
+
+	- A new macro, YY_USER_INIT, is provided for the user to specify
+	  initialization action to be taken on the first call to the
+	  scanner.  This action is done before the scanner does its
+	  own initialization.
+
+	- yy_new_buffer() has been added as an alias for yy_create_buffer()
+
+	- Comments beginning with '#' and extending to the end of the line
+	  now work, but have been deprecated (in anticipation of making
+	  flex recognize #line directives).
+
+	- The funky restrictions on when semi-colons could follow the
+	  YY_NEW_FILE and yyless macros have been removed.  They now
+	  behave identically to functions.
+
+	- A bug in the sample redefinition of YY_INPUT in the documentation
+	  has been corrected.
+
+	- A bug in the sample simple tokener in the documentation has
+	  been corrected.
+
+	- The documentation on the incompatibilities between flex and
+	  lex has been reordered so that the discussion of yylineno
+	  and input() come first, as it's anticipated that these will
+	  be the most common source of headaches.
+
+
+Things which didn't used to be documented but now are:
+
+	- flex interprets "^foo|bar" differently from lex.  flex interprets
+	  it as "match either a 'foo' or a 'bar', providing it comes at the
+	  beginning of a line", whereas lex interprets it as "match either
+	  a 'foo' at the beginning of a line, or a 'bar' anywhere".
+
+	- flex initializes the global "yyin" on the first call to the
+	  scanner, while lex initializes it at compile-time.
+
+	- yy_switch_to_buffer() can be used in the yywrap() macro/routine.
+
+	- flex scanners do not use stdio for their input, and hence when
+	  writing an interactive scanner one must explictly call fflush()
+	  after writing out a prompt.
+
+	- flex scanner can be made reentrant (after a fashion) by using
+	  "yyrestart( yyin );".  This is useful for interactive scanners
+	  which have interrupt handlers that long-jump out of the scanner.
+
+	- a defense of why yylineno is not supported is included, along
+	  with a suggestion on how to convert scanners which rely on it.
+
+
+Other changes:
+
+	- Prototypes and proper declarations of void routines have
+	  been added to the flex source code, courtesy of Kevin B. Kenny.
+
+	- Routines dealing with memory allocation now use void* pointers
+	  instead of char* - see Makefile for porting implications.
+
+	- Error-checking is now done when flex closes a file.
+
+	- Various lint tweaks were added to reduce the number of gripes.
+
+	- Makefile has been further parameterized to aid in porting.
+
+	- Support for SCO Unix added.
+
+	- Flex now sports the latest & greatest UC copyright notice
+	  (which is only slightly different from the previous one).
+
+	- A note has been added to flexdoc.1 mentioning work in progress
+	  on modifying flex to generate straight C code rather than a
+	  table-driven automaton, with an email address of whom to contact
+	  if you are working along similar lines.
+
+
+Changes between 2.2 Patch #3 (30Mar90) and 2.2 Patch #2:
+
+	- fixed bug which caused -I scanners to bomb
+
+
+Changes between 2.2 Patch #2 (27Mar90) and 2.2 Patch #1:
+
+	- fixed bug writing past end of input buffer in yyunput()
+	- fixed bug detecting NUL's at the end of a buffer
+
+
+Changes between 2.2 Patch #1 (23Mar90) and 2.2 (alpha) release:
+
+	- Makefile fixes: definition of MAKE variable for systems
+	  which don't have it; installation of flexdoc.1 along with
+	  flex.1; fixed two bugs which could cause "bigtest" to fail.
+
+	- flex.skel fix for compiling with g++.
+
+	- README and flexdoc.1 no longer list an out-of-date BITNET address
+	  for contacting me.
+
+	- minor typos and formatting changes to flex.1 and flexdoc.1.
+
+
+Changes between 2.2 (alpha) release of March '90 and previous release:
+
+User-visible:
+
+	- Full user documentation now available.
+
+	- Support for 8-bit scanners.
+
+	- Scanners now accept NUL's.
+
+	- A facility has been added for dealing with multiple
+	  input buffers.
+
+	- Two manual entries now.  One which fully describes flex
+	  (rather than just its differences from lex), and the
+	  other for quick(er) reference.
+
+	- A number of changes to bring flex closer into compliance
+	  with the latest POSIX lex draft:
+
+		%t support
+		flex now accepts multiple input files and concatenates
+		    them together to form its input
+		previous -c (compress) flag renamed -C
+		do-nothing -c and -n flags added
+		Any indented code or code within %{}'s in section 2 is
+		    now copied to the output
+
+	- yyleng is now a bona fide global integer.
+
+	- -d debug information now gives the line number of the
+	  matched rule instead of which number rule it was from
+	  the beginning of the file.
+
+	- -v output now includes a summary of the flags used to generate
+	  the scanner.
+
+	- unput() and yyrestart() are now globally callable.
+
+	- yyrestart() no longer closes the previous value of yyin.
+
+	- C++ support; generated scanners can be compiled with C++ compiler.
+
+	- Primitive -lfl library added, containing default main()
+	  which calls yylex().  A number of routines currently living
+	  in the scanner skeleton will probably migrate to here
+	  in the future (in particular, yywrap() will probably cease
+	  to be a macro and instead be a function in the -lfl library).
+
+	- Hexadecimal (\x) escape sequences added.
+
+	- Support for MS-DOS, VMS, and Turbo-C integrated.
+
+	- The %used/%unused operators have been deprecated.  They
+	  may go away soon.
+
+
+Other changes:
+
+	- Makefile enhanced for easier testing and installation.
+	- The parser has been tweaked to detect some erroneous
+	  constructions which previously were missed.
+	- Scanner input buffer overflow is now detected.
+	- Bugs with missing "const" declarations fixed.
+	- Out-of-date Minix/Atari patches provided.
+	- Scanners no longer require printf() unless FLEX_DEBUG is being used.
+	- A subtle input() bug has been fixed.
+	- Line numbers for "continued action" rules (those following
+	  the special '|' action) are now correct.
+	- unput() bug fixed; had been causing problems porting flex to VMS.
+	- yymore() handling rewritten to fix bug with interaction
+	  between yymore() and trailing context.
+	- EOF in actions now generates an error message.
+	- Bug involving -CFe and generating equivalence classes fixed.
+	- Bug which made -CF be treated as -Cf fixed.
+	- Support for SysV tmpnam() added.
+	- Unused #define's for scanner no longer generated.
+	- Error messages which are associated with a particular input
+	  line are now all identified with their input line in standard
+	  format.
+	- % directives which are valid to lex but not to flex are
+	  now ignored instead of generating warnings.
+	- -DSYS_V flag can now also be specified -DUSG for System V
+	  compilation.
+
+
+Changes between 2.1 beta-test release of June '89 and previous release:
+
+User-visible:
+
+	- -p flag generates a performance report to stderr.  The report
+	  consists of comments regarding features of the scanner rules
+	  which result in slower scanners.
+
+	- -b flag generates backtracking information to lex.backtrack.
+	  This is a list of scanner states which require backtracking
+	  and the characters on which they do so.  By adding rules
+	  one can remove backtracking states.  If all backtracking states
+	  are eliminated, the generated scanner will run faster.
+	  Backtracking is not yet documented in the manual entry.
+
+	- Variable trailing context now works, i.e., one can have
+	  rules like "(foo)*/[ \t]*bletch".  Some trailing context
+	  patterns still cannot be properly matched and generate
+	  error messages.  These are patterns where the ending of the
+	  first part of the rule matches the beginning of the second
+	  part, such as "zx*/xy*", where the 'x*' matches the 'x' at
+	  the beginning of the trailing context.  Lex won't get these
+	  patterns right either.
+
+	- Faster scanners.
+
+	- End-of-file rules.  The special rule "<<EOF>>" indicates
+	  actions which are to be taken when an end-of-file is
+	  encountered and yywrap() returns non-zero (i.e., indicates
+	  no further files to process).  See manual entry for example.
+
+	- The -r (reject used) flag is gone.  flex now scans the input
+	  for occurrences of the string "REJECT" to determine if the
+	  action is needed.  It tries to be intelligent about this but
+	  can be fooled.  One can force the presence or absence of
+	  REJECT by adding a line in the first section of the form
+	  "%used REJECT" or "%unused REJECT".
+
+	- yymore() has been implemented.  Similarly to REJECT, flex
+	  detects the use of yymore(), which can be overridden using
+	  "%used" or "%unused".
+
+	- Patterns like "x{0,3}" now work (i.e., with lower-limit == 0).
+
+	- Removed '\^x' for ctrl-x misfeature.
+
+	- Added '\a' and '\v' escape sequences.
+
+	- \<digits> now works for octal escape sequences; previously
+	  \0<digits> was required.
+
+	- Better error reporting; line numbers are associated with rules.
+
+	- yyleng is a macro; it cannot be accessed outside of the
+	  scanner source file.
+
+	- yytext and yyleng should not be modified within a flex action.
+
+	- Generated scanners #define the name FLEX_SCANNER.
+
+	- Rules are internally separated by YY_BREAK in lex.yy.c rather
+	  than break, to allow redefinition.
+
+	- The macro YY_USER_ACTION can be redefined to provide an action
+	  which is always executed prior to the matched rule's action.
+	
+	- yyrestart() is a new action which can be used to restart
+	  the scanner after it has seen an end-of-file (a "real" one,
+	  that is, one for which yywrap() returned non-zero).  It takes
+	  a FILE* argument indicating a new file to scan and sets
+	  things up so that a subsequent call to yylex() will start
+	  scanning that file.
+
+	- Internal scanner names all preceded by "yy_"
+
+	- lex.yy.c is deleted if errors are encountered during processing.
+
+	- Comments may be put in the first section of the input by preceding
+	  them with '#'.
+
+
+
+Other changes:
+
+	- Some portability-related bugs fixed, in particular for machines
+	  with unsigned characters or sizeof( int* ) != sizeof( int ).
+	  Also, tweaks for VMS and Microsoft C (MS-DOS), and identifiers all
+	  trimmed to be 31 or fewer characters.  Shortened file names
+	  for dinosaur OS's.  Checks for allocating > 64K memory
+	  on 16 bit'ers.  Amiga tweaks.  Compiles using gcc on a Sun-3.
+	- Compressed and fast scanner skeletons merged.
+	- Skeleton header files done away with.
+	- Generated scanner uses prototypes and "const" for __STDC__.
+	- -DSV flag is now -DSYS_V for System V compilation.
+	- Removed all references to FTL language.
+	- Software now covered by BSD Copyright.
+	- flex will replace lex in subsequent BSD releases.