| 1 | The -r option has been implemented. The -r option tells Yacc to
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| 2 | put the read-only tables in y.tab.c and the code and variables in
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| 3 | y.code.c. Keith Bostic asked for this option so that :yyfix could be
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| 4 | eliminated.
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| 5 |
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| 6 | The -l and -t options have been implemented. The -l option tells
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| 7 | Yacc not to include #line directives in the code it produces. The -t
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| 8 | option causes debugging code to be included in the compiled parser.
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| 9 |
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| 10 | The code for error recovery has been changed to implement the same
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| 11 | algorithm as AT&T Yacc. There will still be differences in the way
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| 12 | error recovery works because AT&T Yacc uses more default reductions
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| 13 | than Berkeley Yacc.
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| 14 |
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| 15 | The environment variable TMPDIR determines the directory where
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| 16 | temporary files will be created. If TMPDIR is defined, temporary files
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| 17 | will be created in the directory whose pathname is the value of TMPDIR.
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| 18 | By default, temporary files are created in /tmp.
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| 19 |
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| 20 | The keywords are now case-insensitive. For example, %nonassoc,
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| 21 | %NONASSOC, %NonAssoc, and %nOnAsSoC are all equivalent.
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| 22 |
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| 23 | Commas and semicolons that are not part of C code are treated as
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| 24 | commentary.
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| 25 |
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| 26 | Line-end comments, as in BCPL, are permitted. Line-end comments
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| 27 | begin with // and end at the next end-of-line. Line-end comments are
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| 28 | permitted in C code; they are converted to C comments on output.
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| 29 |
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| 30 | The form of y.output files has been changed to look more like
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| 31 | those produced by AT&T Yacc.
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| 32 |
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| 33 | A new kind of declaration has been added. The form of the declaration
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| 34 | is
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| 35 |
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| 36 | %ident string
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| 37 |
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| 38 | where string is a sequence of characters begining with a double quote
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| 39 | and ending with either a double quote or the next end-of-line, whichever
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| 40 | comes first. The declaration will cause a #ident directive to be written
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| 41 | near the start of the output file.
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| 42 |
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| 43 | If a parser has been compiled with debugging code, that code can be
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| 44 | enabled by setting an environment variable. If the environment variable
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| 45 | YYDEBUG is set to 0, debugging output is suppressed. If it is set to 1,
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| 46 | debugging output is written to standard output.
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