1*46059Scorbett The -r option has been implemented. The -r option tells Yacc to 2*46059Scorbettput the read-only tables in y.tab.c and the code and variables in 3*46059Scorbetty.code.c. Keith Bostic asked for this option so that :yyfix could be 4*46059Scorbetteliminated. 539771Sbostic 639771Sbostic The -l and -t options have been implemented. The -l option tells 739771SbosticYacc not to include #line directives in the code it produces. The -t 839771Sbosticoption causes debugging code to be included in the compiled parser. 939771Sbostic 1039771Sbostic The code for error recovery has been changed to implement the same 1139771Sbosticalgorithm as AT&T Yacc. There will still be differences in the way 1239771Sbosticerror recovery works because AT&T Yacc uses more default reductions 13*46059Scorbettthan Berkeley Yacc. 1439771Sbostic 1539771Sbostic The environment variable TMPDIR determines the directory where 1639771Sbostictemporary files will be created. If TMPDIR is defined, temporary files 1739771Sbosticwill be created in the directory whose pathname is the value of TMPDIR. 1839771SbosticBy default, temporary files are created in /tmp. 1939771Sbostic 2039771Sbostic The keywords are now case-insensitive. For example, %nonassoc, 2139771Sbostic%NONASSOC, %NonAssoc, and %nOnAsSoC are all equivalent. 2239771Sbostic 2339771Sbostic Commas and semicolons that are not part of C code are treated as 2439771Sbosticcommentary. 2539771Sbostic 2639771Sbostic Line-end comments, as in BCPL, are permitted. Line-end comments 2739771Sbosticbegin with // and end at the next end-of-line. Line-end comments are 2839771Sbosticpermitted in C code; they are converted to C comments on output. 2939771Sbostic 3039771Sbostic The form of y.output files has been changed to look more like 3139771Sbosticthose produced by AT&T Yacc. 3239771Sbostic 3339771Sbostic A new kind of declaration has been added. The form of the declaration 3439771Sbosticis 3539771Sbostic 3639771Sbostic %ident string 3739771Sbostic 3839771Sbosticwhere string is a sequence of characters begining with a double quote 3939771Sbosticand ending with either a double quote or the next end-of-line, whichever 4039771Sbosticcomes first. The declaration will cause a #ident directive to be written 4139771Sbosticnear the start of the output file. 4239771Sbostic 4339771Sbostic If a parser has been compiled with debugging code, that code can be 4439771Sbosticenabled by setting an environment variable. If the environment variable 4539771SbosticYYDEBUG is set to 0, debugging output is suppressed. If it is set to 1, 4639771Sbosticdebugging output is written to standard output. 47