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.