Changes between 2.0.1 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 "<>" 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. - \ now works for octal escape sequences; previously \0 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.